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Quality of life and colorectal cancer: a review

Quality of life and colorectal cancer: a review Jeff Dunn Queensland Cancer Fund; School of Social Science, University of Queensland; School of Population Health, University of Queensland Abstract Objectives: To describe what is known of quality of life for colorectal cancer patients, to review what has been done in the Australian setting and to identify emerging directions for future research to address current gaps in knowledge. Brigid Lynch Queensland Cancer Fund; School of Population Health, University of Queensland Joanne Aitken Queensland Cancer Fund; School of Population Health, University of Queensland; School of Public Health, Queensland University of Technology Method: A literature search (using Medline, PsychInfo, CINAHL and Sociological Abstracts) was conducted and 41 articles identified for review. Barbara Leggett Royal Brisbane Hospital, Queensland Results: Three key areas relating to quality of life in colorectal cancer patients emerged from the literature review: the definition and measurement of quality of life; predictors of quality of life; and the relationship of quality of life to survival. Results of existing studies are inconsistent in relation to quality of life over time and its relationship to survival. Small sample sizes and methodological limitations make interpretation difficult. Kenneth Pakenham School of Psychology, University of Queensland Beth Newman School of Public Health, Queensland University of Technology olorectal cancer is the most common invasive cancer in Australia affecting both men and women, accounting for 11,245 new cases and 4,678 deaths in 1997.1 Approximately one in every 20 Australians will develop the disease in their lifetime, with the risk increasing progressively with age and greatest in those over 50.2,3 Prognosis varies with the extent of the disease at diagnosis; five-year survival is approximately 90% for patients with local disease only, compared with 7% for those diagnosed with metastatic disease.2,3 Symptoms may not be apparent until late in the course of the disease and as a consequence it is often diagnosed at an advanced stage. While incidence rates for colorectal cancer have remained largely unchanged over the past two decades, mortality rates have fallen steadily due in part to improved surgical techniques and adjuvant therapy.3 Screening for colorectal cancer is already recommended by the National Health and Medical Research Council for asymptomatic individuals from the age of 50 years3 and the Australian Government is currently assessing the feasibility of faecal occult blood testing (FOBT) as a method of population screening for colorectal cancer.4 These initiatives are likely to improve early detection and survival and will further increase the prevalence of colorectal cancer. The rising prevalence of colorectal cancer is likely to be responsible for increasing physical and psychosocial morbidity in the Australian community,1 although the magnitude of this public health burden is yet to be established. Although considerable research has been conducted on morbidity and quality of life experienced by colorectal cancer patients during treatment and in the following year or so after, there is limited information regarding quality of life for individuals who have survived beyond the first year posttreatment.5-7 Understanding the quality of life experienced by survivors of colorectal Conclusions: There is a need for largescale, longitudinal, population-based studies describing the quality of life experienced by colorectal cancer patients and its determinants. Measurement and simultaneous adjustment for potential confounding factors would productively advance knowledge in this area, as would an analysis of the economic cost of morbidity to the community and an assessment of the cost effectiveness of proposed interventions. Implications: As the Australian population ages, the prevalence of colorectal cancer within the community will increase. This burden of disease presents as a priority area for public health research. An improved understanding of quality of life and its predictors will inform the development and design of supportive interventions for those affected by the disease. (Aust N Z J Public Health 2003; 27: 41-53) Correspondence to: Dr Jeff Dunn, Queensland Cancer Fund, PO Box 201, Spring Hill, Queensland 4004. Fax: (07) 3257 1306; e-mail: jdunn@qldcancer.com.au Submitted: June 2002 Revision requested: September 2002 Accepted: November 2002 2003 VOL. 27 NO. 1 AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH Dunn et al. cancer is essential for evaluating the full impact of the disease on the individual, their family and their community.5,6 Further, such information is vital for the development of interventions to improve the health and well-being of the growing population of colorectal cancer survivors.3 There is an enormous potential to improve patient well-being and quality of life over time if patient needs are identified. With this in mind, the aims of this review are to describe what is known of the major predictors of quality of life for colorectal cancer patients, to discuss the prognostic value of measuring quality of life at diagnosis, to review what has been done in the Australian setting and to identify directions for future research that would address gaps in knowledge identified by this review. Results Description of studies reviewed Of the 24 experimental studies reporting primary data, 15 were of a cross-sectional design,5,7-20 six were prospective21-25,45 and three were descriptive.6,26,27 The other 17 articles comprised seven editorial or expert opinion pieces;28-34 five papers describing the development and testing of quality of life measures;35-39 two metaanalyses;40,41 two reports based on secondary analysis of data from other studies;42,43 and one literature review.44 Appendix 1 summarises the studies selected for this review. More than half the research reviewed (24 articles) was conducted in the US.5,7,9-14,16,18,19,25-27,30,32-35,37,39,41-43,45 The remainder came from the Netherlands (n=4),21,28,29,38 Australia (n=2),31,36 Canada (n=3),6,22,44 the UK (n=3),15,17,40 Sweden (n=2)23,24 and Israel (n=1).8 One study collected data in 10 different countries.20 There was no apparent standardised instrument used across the studies to assess quality of life and related constructs. A wide variety of measures were used in the data collection process, including the Brief Symptom Inventory,8,11,19 the Functional Assessment of Cancer Therapy,5,22,35,39 the Psychological Adjustment to Illness Scale,8,21 the Profile of Mood State18,39 and the Multidimensional Quality of Life Scale – Cancer version.43 A number of studies used purpose-designed interviews or focus groups to collect quality of life and psychosocial adjustment data.6,15,26,27,42 Upon analysing the 41 articles selected for this review, three key areas that relate to quality of life in colorectal cancer patients emerged. These were, first, the definition and measurement of quality of life, second, predictors of quality of life and, third, the relationship of quality of life to survival. Method Literature search strategy Articles describing quality of life in colorectal cancer patients were identified using four electronic databases: Medline (19792000); CINAHL (1982-01/2001); Psychinfo (1977-02/2001); and Sociological Abstracts (1963-2000). The search strategy identified articles that had ‘colorectal cancer’ or ‘colorectal neoplasm(s)’ and ‘quality of life’ or ‘cost of illness’ or ‘lifestyle’ or ‘sickness impact’ in the key words or text of the title or abstract. Papers written in English and published between 1980 and 2001 were considered. The literature search was then repeated with ‘Australia*’ included as an extra search criterion, meaning that matching articles would contain the word ‘Australia’, ‘Australian’ or ‘Australians’ in their title, abstract or key words. Selection of articles for review The literature search identified 313 matching articles using the Medline database, 130 matching articles using the CINAHL database, 11 articles using Psychinfo and none using Sociological Abstracts. The Medline search was further refined to 172 articles using the keywords ‘stage of disease’ or ‘neoplasm staging’; ‘cancer and care’; and ‘palliative’ or ‘palliation’ or ‘patient care’. The Australian literature search revealed nine matching articles using Medline, 12 articles using CINAHL, one article using Psychinfo and no matching articles using Sociological Abstracts. The authors reviewed the titles and abstracts of all the articles identified to assess their relevance to the study. Papers were included for review if they related to quality of life experienced by people with colorectal cancer. Papers solely describing treatment regimens, screening procedures or cancer prevention were excluded. Thirty-one articles were selected for initial review, of which four were later excluded as they were judged not to meet the criteria for this review (one article was a descriptive piece about the author’s experiences treating dying cancer patients; another dealt with recent life changes and colorectal cancer onset and the other two articles were surveys of public knowledge of colorectal cancer symptoms). A further 14 papers that related to the aim of the study were referenced in the selected articles and were included in this review, for a final total of 41 articles. Quality of life – definition and measurement Quality of life is a fundamentally subjective concept and as such no single definition has gained universal adoption. Researchers define quality of life as a multidimensional concept encompassing an individual’s perceived physical, psychosocial and emotional functioning.7,14,23,26,28-30,33,43,44 It also encompasses domains such as sexual functioning, spiritual well-being and vocational or role performance.7,26,43,44 The World Health Organization (WHO) defines quality of life as “an individual’s perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns. It is a broad-ranging concept affected in a complex way by the person’s physical health, psychological state, personal beliefs, social relationships and their relationship to salient features of their environment”. With the aid of 15 collaborating centres around the world, WHO has defined 24 facets of quality of life and derived response scales for the development of two instruments for measuring quality of life (the WHOL-100 and the WHOQOL-BREF) that can be used in a variety of cultural settings while allowing the results from different populations and countries to be compared.46 For the purpose of this review, the authors conceptualise quality of life as the degree of physical, emotional, social and spiritual well-being as perceived by the patient. 2003 VOL. 27 NO. 1 AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH Common Concerns: Uncommon Perspectives Quality of life and colorectal cancer In recent years, there has been a growing interest in assessing cancer therapies not only in terms of objective, biologic response and patient survival but also in terms of the patient’s quality of life during and following treatment.12,25,28,32,34,45 Quality of life is now regarded in clinical trials as almost or as important an end point as survival.32,45 Quality-of-life assessment in oncology serves a number of functions. First, quality of life information complements objective, medical assessment of treatment outcomes. Improvement in tumour response and patient survival at the expense of patient quality of life is not an optimum result. Changes can be made to treatment regimes or clinical practices if quality of life is found to be compromised.28,29 In the clinical trial setting, quality of life assessment can help discriminate between competing treatments that may achieve similar outcomes in terms of survival.28,29,45 Second, quality of life assessment is important when palliation is the objective of medical intervention.12,25,35,40,45 In patients with advanced-stage disease, cancer therapies may compromise quality of life rather than enhance patient well-being.34 Quality-oflife measures can also bring to light patients’ unmet emotional, social and spiritual concerns, all of which might usefully be addressed in a palliative care setting.32 Third, quality-of-life information is also necessary for evaluating the impact of disease on survivors.5,7,34 Despite the prevalence of colorectal cancer in Western countries, little is known about patients’ quality of life status over time and the long-term effects of cancer treatment.5,7 Prospective, longitudinal studies are needed to establish the burden of disease carried by colorectal cancer survivors in the community setting.5,6,21 Quality of life, being a subjective, patient-rated concept, is difficult to quantify. Structured questionnaires are generally used to measure quality of life32 and there are a multitude of instruments currently available, some generic and some disease-specific. The wide range of available instruments presents researchers with a potentially confusing and complex assortment of options. Not all of the instruments created to measure quality of life have addressed methodological issues such as validity and reliability.12,35 Even carefully designed and tested instruments that are currently being widely used are still undergoing revision and adjustment.45 Without standardised instruments, it is difficult to compare the findings of different studies as the various instruments available for assessing quality of life may differ in the dimensions that they actually measure.28,30 Nevertheless, Aaronson et al.28,29 caution against identifying one ‘gold standard’ instrument for quality-of-life assessment as doing so would risk adopting an instrument that could potentially be bettered with continued attempts at refinement. Instruments designed purposely to assess quality of life in specific circumstances will have higher internal validity than generic instruments and will provide more meaningful data. The emerging consensus regarding the most efficacious type of quality-of-life measure seems to be an overall, generic instrument comprised of multiple dimensions, supplemented by a disease-specific subscale.28,44,45 The inclusion of a direct, global 2003 VOL. 27 NO. 1 measure of quality of life has also been suggested.44 This is preferable to simply aggregating the scores for the different dimensions to give one overall measure of quality of life. Individuals will value high functioning in some dimensions more strongly than in others, but determining how to weight the various dimensions of quality of life for each individual has yet to be described.30,44 Predictors of quality of life A number of factors have been shown to be associated with the nature and degree of quality of life reported by colorectal cancer patients. These factors clump into five broad categories: demographic characteristics; disease descriptors; time since diagnosis; support received; and lifestyle factors. 1. Demographic characteristics. Little clear evidence emerges from the literature describing the effect of demographic characteristics such as sex and age upon the quality of life in colorectal cancer patients. Baider et al.8 reported better psychosocial adjustment in male colon cancer patients than in female patients. Dibble et al.43 found no significant difference in overall quality of life between male and female cancer patients; however, female patients were shown to have better interpersonal well-being than male patients. Klemm et al.14 found that the demands of illness were higher for younger patients than for older patients and MacDonald et al.15 showed that younger rectal cancer patients felt more stigmatised than older patients, whereas Forsberg et al.23,24 report no significant effect of sex or age upon the quality of life in colorectal and gastric cancer patients. Low-income earners are more likely to have reduced quality of life when compared with patients with higher incomes.5,14 For example, Ramsey et al.5 found that low-income status was significantly correlated with worse outcomes in the physical, social and emotional well-being dimensions of a quality-of-life scale. 2. Disease descriptors. Although morbidity and mortality remain central measures of treatment success, patients’ ability to perform daily living tasks and their general sense of well-being are being increasingly recognised as important outcomes of therapy that should also be considered.24 The stage and site of colorectal cancer at diagnosis are inherently associated with subsequent quality of life, as they determine symptoms, which treatment modalities will be used and the duration of the therapy.33 Therefore, stage and site influence many of the treatment-associated morbidities that may compromise patients’ quality of life.26,33 The Dukes system of clinicopathological staging is widely used to describe the extent of tumour spread and the presence or absence of metastases. The Dukes A, B, C and D stages correlate well with patient survival.3 Pathological staging (pTNM – tumour, node, metastasis) is also a commonly used system. The pTNM stages range from 0 (for carcinoma in situ) to IV (tumour with involvement of regional lymph nodes and distant metastasis).3 Tumour site determines what type of surgery will be undertaken, for example some colon cancers may require a hemicolectomy, whereas rectal cancers may require an anterior resection (a bigger operation than a hemicolectomy) or, less commonly, an AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH Dunn et al. Article abdominoperineal resection which results in a permanent stoma.3 Ramsey et al.5 found that colorectal cancer patients with pTNM Stage I and Stage IV disease experienced relatively consistent increases and decreases, respectively, in quality of life from their time of diagnosis. Those with Stage II and Stage III disease experienced an initial decline in their quality of life, which then improved over time. Patients who require a permanent stoma score lower on quality-of-life scales than patients who undergo sphincter-saving resection.15,17,32 In particular, patients with a colostomy have reported lower quality of life in relation to social factors such as employment, leisure pursuits and sexual function.15,17 Bekkers et al.21 found that stoma patients initially had significant problems, especially in relation to work and sexual function, however these problems diminished during the course of the first post-operative year. The same study found that both stoma and non-stoma patients experienced similar levels of psychosocial problems four years after surgery; however, patients with stomas were more likely to have dropped out of the study prior to the end of the four-year follow-up period.21 It is not clear from these results whether the lower levels of quality of life initially experienced by patients with stomas continues or diminishes over time. Adjuvant therapies (primarily chemotherapy, but also radiation therapy for some rectal cancers) impact upon the quality of life of colorectal cancer patients. If patients require multi-modal therapy they may experience distress and discomfort as a result of adverse reactions and complications related to their treatment course.19,32 The toxicity of these treatments is a particularly important factor that can affect patient quality of life, although patients who experience adverse effects and are able to provide input into the adjustment of their treatment regimens tend to be more satisfied.6 For patients with advanced colorectal cancer, quality of life is very much dependent on control of pain.32 Health-related quality of life is increasingly being used as an outcome measure in clinical trials.47 However, efforts to compare across clinical trials are confounded by inconsistencies in the way quality of life is measured and reported. It is evident that some standardisation would be of benefit here and while a number of authors have suggested guidelines48,49 and several international groups are working to this end, internationally agreed standards are unlikely in the near future.50 3. Time since diagnosis. Time since diagnosis is associated with quality of life in colorectal cancer patients. The passage of time appears to improve patient quality of life,5,7 possibly because of a reduction in the illness-related demands experienced, or perhaps due to patient adjustment to the disease.14 However, very few studies have addressed quality of life in cancer survivors, so long-term physical or psychological problems resulting from colorectal cancer diagnosis and treatment are yet to be properly explored.7 In a study involving 117 colon cancer patients, Schag et al.7 showed a positive association between quality of life and time since diagnosis. The improvement over time was most evident in the psychosocial domain, although there was some improvement in all areas except for sexuality, which remained the same. Ramsey et al.5 report the impact of colorectal cancer on quality of life as being most apparent in the first two to three years post diagnosis. Quality of life was found to stabilise at a relatively high level three years after diagnosis, except in colorectal cancer patients with Stage IV disease. However, Moinpour et al.25 note that quality of life status is often overestimated, as only data collected from patients who survive and are well enough to participate in research studies is utilised. 4. Support received. Support from partners, family, friends and health care providers appears to influence the quality of life experienced by colorectal cancer patients. Sahay et al.6 describe patient satisfaction with their cancer specialists based on information provision and communication. Patients who felt that they were well informed throughout the process of their treatment were satisfied with their care. Most patients seemed to equate involvement in their care with information provision. The relationship between colorectal cancer patients and their families, and spouses in particular, is related to patient quality of life. Patients who live alone report lower perceived well-being than those who live with family.23,24 Patients report receiving most of their emotional and instrumental support from spouses and families.6 While social support appears to be associated with better patient reported quality of life, further research is required to examine potential differential relations between types of social support (e.g. information, emotional, advice, and practical support) and specific quality of life domains. Furthermore, the potential adverse effects of social support efforts have not been examined. 5. Lifestyle factors. Lifestyle factors, exercise in particular, may also play a role in determining the quality of life experienced by colorectal cancer patients. Current evidence suggests that physical activity may be effective in maximising quality of life following diagnosis. In a small, prospective study of postsurgical colorectal cancer patients, Courneya et al.22 found that increasing the frequency of mild exercise undertaken correlated positively with quality of life at follow-up four months later. Exercise has been shown to elevate a range of quality of life factors, including physical, psychological and social well-being; however, little research has been conducted in this field.22,51 Relationship to survival There is some evidence to suggest that the quality of life experienced by colorectal cancer patients is prognostic of subsequent survival; however, potential confounding by stage of disease makes interpretation of existing studies difficult. In a retrospective analysis of 173 colorectal cancer patients, Ramsey et al.5 discovered that patients who died within 12 months of being surveyed had lower quality-of-life scores compared with those who lived beyond 12 months, although this may simply have been a function of their more advanced disease at diagnosis. Sloan et al.45 also found that higher quality-of-life scores were somewhat prognostic of improved survival. In this study of patients with advanced colorectal cancer undergoing chemotherapy, the median survival duration for patients with high quality-of-life scores was 2003 VOL. 27 NO. 1 AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH Common Concerns: Uncommon Perspectives Quality of life and colorectal cancer 5.8 months, compared with a median of 3.7 months for patients with low quality-of-life scores (Wilcoxon p=0.01). Coates et al.20 showed a significant independent association between qualityof-life scores and survival duration in a large sample of patients with advanced malignancies. Studies assessing psychosocial adjustment in colorectal cancer patients also found that survival was significantly associated with a number of psychosocial variables that constitute quality of life. Bekkers et al.21 assessed the psychosocial adjustment of people who had undergone major bowel surgery (for either colorectal cancer or for treatment of a benign disease). Significant differences in regard to work, sexuality and psychological distress were identified between those who survived four years after surgery and those who had died or dropped out of the study. Jepson et al.13 found that personal and social competence had a significant effect on the survival of cancer patients (approximately a quarter of whom had colorectal cancer) independent of illness severity. Discussion Australia has one of the highest colorectal cancer case-survival rates in the world and the overall five-year case survival rate in Australia is reportedly rising.3 Many people diagnosed with colorectal cancer today survive the disease3 and these numbers are expected to increase with continuing advances in treatment. Thus, as the Australian population ages the prevalence of colorectal cancer will rise. Gaining a comprehensive understanding of the issues surrounding quality of life in colorectal cancer patients will enhance current ability to understand the burden of disease for patients as well as the community, and to better design appropriate interventions. Little is known about changes in colorectal cancer patients’ quality of life over time5,6 as studies examining quality of life in colorectal cancer patients beyond one year post-surgery are few. Only six studies identified by this review were of a prospective design21-25,45 and only two of them collected quality-of-life information at least 12 months post-surgery.21,24 For these two studies, samples were small and retention rates were low, raising a question about the generalisability of the results to the broader patient population. One of these longitudinal studies had an initial sample of 96 but had only 69 (72%) remaining one year after surgery;24 the other study began with 123 participants, which reduced to 99 (80%) at one year follow-up and 68 (55%) remained in the study four years after surgery.21 The need exists for large, longitudinal studies into the quality of life experienced by survivors of colorectal cancer and also for standardisation of quality-of-life measures to allow comparison of research findings. Incorporating an economic analysis into any such studies would be enlightening. This economic analysis might usefully address the economic burden of morbidity upon survivors of colorectal cancer as well as the cost effectiveness of any proposed interventions. Limited evidence is available on the ability of quality of life to predict survival in colorectal cancer patients, in part again 2003 VOL. 27 NO. 1 because of the methodological limitations of existing studies. A multitude of confounding factors, such as the stage and site of the tumour and the treatment received, will have an impact on both quality of life and survival. Of the five studies5,9,13,21,45 identified in the literature over the past 20 years that dealt with the prognostic value of quality of life and its component dimensions for colorectal cancer, only two were prospective,21,45 while the other three5,9,13 were cross-sectional studies that obtained survival data at a later point and performed retrospective survival analyses. None of the above studies involved a sample of more than 200 colorectal cancer patients. While four of the studies controlled for the potential confounding effect of stage,9,13,21,45 only two controlled for treatment type, age and other demographic characteristics.13,21 The prognostic value of quality of life in colorectal cancer clearly emerges as an area for further detailed investigation, on a prospective basis and with the simultaneous measurement of and adjustment for potential confounders. Although a number of factors including demographic and disease characteristics, time since diagnosis, social support and physical activity have been identified as predictors or correlates of quality of life in colorectal patients, it is difficult to integrate these findings into a coherent framework, mainly due to the inability to compare across studies, their methodological limitations and the absence of a theoretical basis for modelling predictors of quality of life. Theoretical frameworks such as stress and coping theory52 have been found to have utility in predicting quality of life in other chronic illnesses53 and may inform future investigation of potential determinants of quality of life and subsequent supportive interventions for colorectal cancer patients. Quality of life and colorectal cancer, in terms of burden of disease, presents as a priority area for public health research. A comprehensive understanding of the issues surrounding quality of life and its determinants in survivors of colorectal cancer, including the impact of the disease on patients and their families, would make a significant contribution to reducing the escalating burden of this disease within our community http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Australian and New Zealand Journal of Public Health Wiley

Quality of life and colorectal cancer: a review

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Wiley
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Copyright © 2003 Wiley Subscription Services, Inc., A Wiley Company
ISSN
1326-0200
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1753-6405
DOI
10.1111/j.1467-842X.2003.tb00378.x
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Abstract

Jeff Dunn Queensland Cancer Fund; School of Social Science, University of Queensland; School of Population Health, University of Queensland Abstract Objectives: To describe what is known of quality of life for colorectal cancer patients, to review what has been done in the Australian setting and to identify emerging directions for future research to address current gaps in knowledge. Brigid Lynch Queensland Cancer Fund; School of Population Health, University of Queensland Joanne Aitken Queensland Cancer Fund; School of Population Health, University of Queensland; School of Public Health, Queensland University of Technology Method: A literature search (using Medline, PsychInfo, CINAHL and Sociological Abstracts) was conducted and 41 articles identified for review. Barbara Leggett Royal Brisbane Hospital, Queensland Results: Three key areas relating to quality of life in colorectal cancer patients emerged from the literature review: the definition and measurement of quality of life; predictors of quality of life; and the relationship of quality of life to survival. Results of existing studies are inconsistent in relation to quality of life over time and its relationship to survival. Small sample sizes and methodological limitations make interpretation difficult. Kenneth Pakenham School of Psychology, University of Queensland Beth Newman School of Public Health, Queensland University of Technology olorectal cancer is the most common invasive cancer in Australia affecting both men and women, accounting for 11,245 new cases and 4,678 deaths in 1997.1 Approximately one in every 20 Australians will develop the disease in their lifetime, with the risk increasing progressively with age and greatest in those over 50.2,3 Prognosis varies with the extent of the disease at diagnosis; five-year survival is approximately 90% for patients with local disease only, compared with 7% for those diagnosed with metastatic disease.2,3 Symptoms may not be apparent until late in the course of the disease and as a consequence it is often diagnosed at an advanced stage. While incidence rates for colorectal cancer have remained largely unchanged over the past two decades, mortality rates have fallen steadily due in part to improved surgical techniques and adjuvant therapy.3 Screening for colorectal cancer is already recommended by the National Health and Medical Research Council for asymptomatic individuals from the age of 50 years3 and the Australian Government is currently assessing the feasibility of faecal occult blood testing (FOBT) as a method of population screening for colorectal cancer.4 These initiatives are likely to improve early detection and survival and will further increase the prevalence of colorectal cancer. The rising prevalence of colorectal cancer is likely to be responsible for increasing physical and psychosocial morbidity in the Australian community,1 although the magnitude of this public health burden is yet to be established. Although considerable research has been conducted on morbidity and quality of life experienced by colorectal cancer patients during treatment and in the following year or so after, there is limited information regarding quality of life for individuals who have survived beyond the first year posttreatment.5-7 Understanding the quality of life experienced by survivors of colorectal Conclusions: There is a need for largescale, longitudinal, population-based studies describing the quality of life experienced by colorectal cancer patients and its determinants. Measurement and simultaneous adjustment for potential confounding factors would productively advance knowledge in this area, as would an analysis of the economic cost of morbidity to the community and an assessment of the cost effectiveness of proposed interventions. Implications: As the Australian population ages, the prevalence of colorectal cancer within the community will increase. This burden of disease presents as a priority area for public health research. An improved understanding of quality of life and its predictors will inform the development and design of supportive interventions for those affected by the disease. (Aust N Z J Public Health 2003; 27: 41-53) Correspondence to: Dr Jeff Dunn, Queensland Cancer Fund, PO Box 201, Spring Hill, Queensland 4004. Fax: (07) 3257 1306; e-mail: jdunn@qldcancer.com.au Submitted: June 2002 Revision requested: September 2002 Accepted: November 2002 2003 VOL. 27 NO. 1 AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH Dunn et al. cancer is essential for evaluating the full impact of the disease on the individual, their family and their community.5,6 Further, such information is vital for the development of interventions to improve the health and well-being of the growing population of colorectal cancer survivors.3 There is an enormous potential to improve patient well-being and quality of life over time if patient needs are identified. With this in mind, the aims of this review are to describe what is known of the major predictors of quality of life for colorectal cancer patients, to discuss the prognostic value of measuring quality of life at diagnosis, to review what has been done in the Australian setting and to identify directions for future research that would address gaps in knowledge identified by this review. Results Description of studies reviewed Of the 24 experimental studies reporting primary data, 15 were of a cross-sectional design,5,7-20 six were prospective21-25,45 and three were descriptive.6,26,27 The other 17 articles comprised seven editorial or expert opinion pieces;28-34 five papers describing the development and testing of quality of life measures;35-39 two metaanalyses;40,41 two reports based on secondary analysis of data from other studies;42,43 and one literature review.44 Appendix 1 summarises the studies selected for this review. More than half the research reviewed (24 articles) was conducted in the US.5,7,9-14,16,18,19,25-27,30,32-35,37,39,41-43,45 The remainder came from the Netherlands (n=4),21,28,29,38 Australia (n=2),31,36 Canada (n=3),6,22,44 the UK (n=3),15,17,40 Sweden (n=2)23,24 and Israel (n=1).8 One study collected data in 10 different countries.20 There was no apparent standardised instrument used across the studies to assess quality of life and related constructs. A wide variety of measures were used in the data collection process, including the Brief Symptom Inventory,8,11,19 the Functional Assessment of Cancer Therapy,5,22,35,39 the Psychological Adjustment to Illness Scale,8,21 the Profile of Mood State18,39 and the Multidimensional Quality of Life Scale – Cancer version.43 A number of studies used purpose-designed interviews or focus groups to collect quality of life and psychosocial adjustment data.6,15,26,27,42 Upon analysing the 41 articles selected for this review, three key areas that relate to quality of life in colorectal cancer patients emerged. These were, first, the definition and measurement of quality of life, second, predictors of quality of life and, third, the relationship of quality of life to survival. Method Literature search strategy Articles describing quality of life in colorectal cancer patients were identified using four electronic databases: Medline (19792000); CINAHL (1982-01/2001); Psychinfo (1977-02/2001); and Sociological Abstracts (1963-2000). The search strategy identified articles that had ‘colorectal cancer’ or ‘colorectal neoplasm(s)’ and ‘quality of life’ or ‘cost of illness’ or ‘lifestyle’ or ‘sickness impact’ in the key words or text of the title or abstract. Papers written in English and published between 1980 and 2001 were considered. The literature search was then repeated with ‘Australia*’ included as an extra search criterion, meaning that matching articles would contain the word ‘Australia’, ‘Australian’ or ‘Australians’ in their title, abstract or key words. Selection of articles for review The literature search identified 313 matching articles using the Medline database, 130 matching articles using the CINAHL database, 11 articles using Psychinfo and none using Sociological Abstracts. The Medline search was further refined to 172 articles using the keywords ‘stage of disease’ or ‘neoplasm staging’; ‘cancer and care’; and ‘palliative’ or ‘palliation’ or ‘patient care’. The Australian literature search revealed nine matching articles using Medline, 12 articles using CINAHL, one article using Psychinfo and no matching articles using Sociological Abstracts. The authors reviewed the titles and abstracts of all the articles identified to assess their relevance to the study. Papers were included for review if they related to quality of life experienced by people with colorectal cancer. Papers solely describing treatment regimens, screening procedures or cancer prevention were excluded. Thirty-one articles were selected for initial review, of which four were later excluded as they were judged not to meet the criteria for this review (one article was a descriptive piece about the author’s experiences treating dying cancer patients; another dealt with recent life changes and colorectal cancer onset and the other two articles were surveys of public knowledge of colorectal cancer symptoms). A further 14 papers that related to the aim of the study were referenced in the selected articles and were included in this review, for a final total of 41 articles. Quality of life – definition and measurement Quality of life is a fundamentally subjective concept and as such no single definition has gained universal adoption. Researchers define quality of life as a multidimensional concept encompassing an individual’s perceived physical, psychosocial and emotional functioning.7,14,23,26,28-30,33,43,44 It also encompasses domains such as sexual functioning, spiritual well-being and vocational or role performance.7,26,43,44 The World Health Organization (WHO) defines quality of life as “an individual’s perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards and concerns. It is a broad-ranging concept affected in a complex way by the person’s physical health, psychological state, personal beliefs, social relationships and their relationship to salient features of their environment”. With the aid of 15 collaborating centres around the world, WHO has defined 24 facets of quality of life and derived response scales for the development of two instruments for measuring quality of life (the WHOL-100 and the WHOQOL-BREF) that can be used in a variety of cultural settings while allowing the results from different populations and countries to be compared.46 For the purpose of this review, the authors conceptualise quality of life as the degree of physical, emotional, social and spiritual well-being as perceived by the patient. 2003 VOL. 27 NO. 1 AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH Common Concerns: Uncommon Perspectives Quality of life and colorectal cancer In recent years, there has been a growing interest in assessing cancer therapies not only in terms of objective, biologic response and patient survival but also in terms of the patient’s quality of life during and following treatment.12,25,28,32,34,45 Quality of life is now regarded in clinical trials as almost or as important an end point as survival.32,45 Quality-of-life assessment in oncology serves a number of functions. First, quality of life information complements objective, medical assessment of treatment outcomes. Improvement in tumour response and patient survival at the expense of patient quality of life is not an optimum result. Changes can be made to treatment regimes or clinical practices if quality of life is found to be compromised.28,29 In the clinical trial setting, quality of life assessment can help discriminate between competing treatments that may achieve similar outcomes in terms of survival.28,29,45 Second, quality of life assessment is important when palliation is the objective of medical intervention.12,25,35,40,45 In patients with advanced-stage disease, cancer therapies may compromise quality of life rather than enhance patient well-being.34 Quality-oflife measures can also bring to light patients’ unmet emotional, social and spiritual concerns, all of which might usefully be addressed in a palliative care setting.32 Third, quality-of-life information is also necessary for evaluating the impact of disease on survivors.5,7,34 Despite the prevalence of colorectal cancer in Western countries, little is known about patients’ quality of life status over time and the long-term effects of cancer treatment.5,7 Prospective, longitudinal studies are needed to establish the burden of disease carried by colorectal cancer survivors in the community setting.5,6,21 Quality of life, being a subjective, patient-rated concept, is difficult to quantify. Structured questionnaires are generally used to measure quality of life32 and there are a multitude of instruments currently available, some generic and some disease-specific. The wide range of available instruments presents researchers with a potentially confusing and complex assortment of options. Not all of the instruments created to measure quality of life have addressed methodological issues such as validity and reliability.12,35 Even carefully designed and tested instruments that are currently being widely used are still undergoing revision and adjustment.45 Without standardised instruments, it is difficult to compare the findings of different studies as the various instruments available for assessing quality of life may differ in the dimensions that they actually measure.28,30 Nevertheless, Aaronson et al.28,29 caution against identifying one ‘gold standard’ instrument for quality-of-life assessment as doing so would risk adopting an instrument that could potentially be bettered with continued attempts at refinement. Instruments designed purposely to assess quality of life in specific circumstances will have higher internal validity than generic instruments and will provide more meaningful data. The emerging consensus regarding the most efficacious type of quality-of-life measure seems to be an overall, generic instrument comprised of multiple dimensions, supplemented by a disease-specific subscale.28,44,45 The inclusion of a direct, global 2003 VOL. 27 NO. 1 measure of quality of life has also been suggested.44 This is preferable to simply aggregating the scores for the different dimensions to give one overall measure of quality of life. Individuals will value high functioning in some dimensions more strongly than in others, but determining how to weight the various dimensions of quality of life for each individual has yet to be described.30,44 Predictors of quality of life A number of factors have been shown to be associated with the nature and degree of quality of life reported by colorectal cancer patients. These factors clump into five broad categories: demographic characteristics; disease descriptors; time since diagnosis; support received; and lifestyle factors. 1. Demographic characteristics. Little clear evidence emerges from the literature describing the effect of demographic characteristics such as sex and age upon the quality of life in colorectal cancer patients. Baider et al.8 reported better psychosocial adjustment in male colon cancer patients than in female patients. Dibble et al.43 found no significant difference in overall quality of life between male and female cancer patients; however, female patients were shown to have better interpersonal well-being than male patients. Klemm et al.14 found that the demands of illness were higher for younger patients than for older patients and MacDonald et al.15 showed that younger rectal cancer patients felt more stigmatised than older patients, whereas Forsberg et al.23,24 report no significant effect of sex or age upon the quality of life in colorectal and gastric cancer patients. Low-income earners are more likely to have reduced quality of life when compared with patients with higher incomes.5,14 For example, Ramsey et al.5 found that low-income status was significantly correlated with worse outcomes in the physical, social and emotional well-being dimensions of a quality-of-life scale. 2. Disease descriptors. Although morbidity and mortality remain central measures of treatment success, patients’ ability to perform daily living tasks and their general sense of well-being are being increasingly recognised as important outcomes of therapy that should also be considered.24 The stage and site of colorectal cancer at diagnosis are inherently associated with subsequent quality of life, as they determine symptoms, which treatment modalities will be used and the duration of the therapy.33 Therefore, stage and site influence many of the treatment-associated morbidities that may compromise patients’ quality of life.26,33 The Dukes system of clinicopathological staging is widely used to describe the extent of tumour spread and the presence or absence of metastases. The Dukes A, B, C and D stages correlate well with patient survival.3 Pathological staging (pTNM – tumour, node, metastasis) is also a commonly used system. The pTNM stages range from 0 (for carcinoma in situ) to IV (tumour with involvement of regional lymph nodes and distant metastasis).3 Tumour site determines what type of surgery will be undertaken, for example some colon cancers may require a hemicolectomy, whereas rectal cancers may require an anterior resection (a bigger operation than a hemicolectomy) or, less commonly, an AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH Dunn et al. Article abdominoperineal resection which results in a permanent stoma.3 Ramsey et al.5 found that colorectal cancer patients with pTNM Stage I and Stage IV disease experienced relatively consistent increases and decreases, respectively, in quality of life from their time of diagnosis. Those with Stage II and Stage III disease experienced an initial decline in their quality of life, which then improved over time. Patients who require a permanent stoma score lower on quality-of-life scales than patients who undergo sphincter-saving resection.15,17,32 In particular, patients with a colostomy have reported lower quality of life in relation to social factors such as employment, leisure pursuits and sexual function.15,17 Bekkers et al.21 found that stoma patients initially had significant problems, especially in relation to work and sexual function, however these problems diminished during the course of the first post-operative year. The same study found that both stoma and non-stoma patients experienced similar levels of psychosocial problems four years after surgery; however, patients with stomas were more likely to have dropped out of the study prior to the end of the four-year follow-up period.21 It is not clear from these results whether the lower levels of quality of life initially experienced by patients with stomas continues or diminishes over time. Adjuvant therapies (primarily chemotherapy, but also radiation therapy for some rectal cancers) impact upon the quality of life of colorectal cancer patients. If patients require multi-modal therapy they may experience distress and discomfort as a result of adverse reactions and complications related to their treatment course.19,32 The toxicity of these treatments is a particularly important factor that can affect patient quality of life, although patients who experience adverse effects and are able to provide input into the adjustment of their treatment regimens tend to be more satisfied.6 For patients with advanced colorectal cancer, quality of life is very much dependent on control of pain.32 Health-related quality of life is increasingly being used as an outcome measure in clinical trials.47 However, efforts to compare across clinical trials are confounded by inconsistencies in the way quality of life is measured and reported. It is evident that some standardisation would be of benefit here and while a number of authors have suggested guidelines48,49 and several international groups are working to this end, internationally agreed standards are unlikely in the near future.50 3. Time since diagnosis. Time since diagnosis is associated with quality of life in colorectal cancer patients. The passage of time appears to improve patient quality of life,5,7 possibly because of a reduction in the illness-related demands experienced, or perhaps due to patient adjustment to the disease.14 However, very few studies have addressed quality of life in cancer survivors, so long-term physical or psychological problems resulting from colorectal cancer diagnosis and treatment are yet to be properly explored.7 In a study involving 117 colon cancer patients, Schag et al.7 showed a positive association between quality of life and time since diagnosis. The improvement over time was most evident in the psychosocial domain, although there was some improvement in all areas except for sexuality, which remained the same. Ramsey et al.5 report the impact of colorectal cancer on quality of life as being most apparent in the first two to three years post diagnosis. Quality of life was found to stabilise at a relatively high level three years after diagnosis, except in colorectal cancer patients with Stage IV disease. However, Moinpour et al.25 note that quality of life status is often overestimated, as only data collected from patients who survive and are well enough to participate in research studies is utilised. 4. Support received. Support from partners, family, friends and health care providers appears to influence the quality of life experienced by colorectal cancer patients. Sahay et al.6 describe patient satisfaction with their cancer specialists based on information provision and communication. Patients who felt that they were well informed throughout the process of their treatment were satisfied with their care. Most patients seemed to equate involvement in their care with information provision. The relationship between colorectal cancer patients and their families, and spouses in particular, is related to patient quality of life. Patients who live alone report lower perceived well-being than those who live with family.23,24 Patients report receiving most of their emotional and instrumental support from spouses and families.6 While social support appears to be associated with better patient reported quality of life, further research is required to examine potential differential relations between types of social support (e.g. information, emotional, advice, and practical support) and specific quality of life domains. Furthermore, the potential adverse effects of social support efforts have not been examined. 5. Lifestyle factors. Lifestyle factors, exercise in particular, may also play a role in determining the quality of life experienced by colorectal cancer patients. Current evidence suggests that physical activity may be effective in maximising quality of life following diagnosis. In a small, prospective study of postsurgical colorectal cancer patients, Courneya et al.22 found that increasing the frequency of mild exercise undertaken correlated positively with quality of life at follow-up four months later. Exercise has been shown to elevate a range of quality of life factors, including physical, psychological and social well-being; however, little research has been conducted in this field.22,51 Relationship to survival There is some evidence to suggest that the quality of life experienced by colorectal cancer patients is prognostic of subsequent survival; however, potential confounding by stage of disease makes interpretation of existing studies difficult. In a retrospective analysis of 173 colorectal cancer patients, Ramsey et al.5 discovered that patients who died within 12 months of being surveyed had lower quality-of-life scores compared with those who lived beyond 12 months, although this may simply have been a function of their more advanced disease at diagnosis. Sloan et al.45 also found that higher quality-of-life scores were somewhat prognostic of improved survival. In this study of patients with advanced colorectal cancer undergoing chemotherapy, the median survival duration for patients with high quality-of-life scores was 2003 VOL. 27 NO. 1 AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH Common Concerns: Uncommon Perspectives Quality of life and colorectal cancer 5.8 months, compared with a median of 3.7 months for patients with low quality-of-life scores (Wilcoxon p=0.01). Coates et al.20 showed a significant independent association between qualityof-life scores and survival duration in a large sample of patients with advanced malignancies. Studies assessing psychosocial adjustment in colorectal cancer patients also found that survival was significantly associated with a number of psychosocial variables that constitute quality of life. Bekkers et al.21 assessed the psychosocial adjustment of people who had undergone major bowel surgery (for either colorectal cancer or for treatment of a benign disease). Significant differences in regard to work, sexuality and psychological distress were identified between those who survived four years after surgery and those who had died or dropped out of the study. Jepson et al.13 found that personal and social competence had a significant effect on the survival of cancer patients (approximately a quarter of whom had colorectal cancer) independent of illness severity. Discussion Australia has one of the highest colorectal cancer case-survival rates in the world and the overall five-year case survival rate in Australia is reportedly rising.3 Many people diagnosed with colorectal cancer today survive the disease3 and these numbers are expected to increase with continuing advances in treatment. Thus, as the Australian population ages the prevalence of colorectal cancer will rise. Gaining a comprehensive understanding of the issues surrounding quality of life in colorectal cancer patients will enhance current ability to understand the burden of disease for patients as well as the community, and to better design appropriate interventions. Little is known about changes in colorectal cancer patients’ quality of life over time5,6 as studies examining quality of life in colorectal cancer patients beyond one year post-surgery are few. Only six studies identified by this review were of a prospective design21-25,45 and only two of them collected quality-of-life information at least 12 months post-surgery.21,24 For these two studies, samples were small and retention rates were low, raising a question about the generalisability of the results to the broader patient population. One of these longitudinal studies had an initial sample of 96 but had only 69 (72%) remaining one year after surgery;24 the other study began with 123 participants, which reduced to 99 (80%) at one year follow-up and 68 (55%) remained in the study four years after surgery.21 The need exists for large, longitudinal studies into the quality of life experienced by survivors of colorectal cancer and also for standardisation of quality-of-life measures to allow comparison of research findings. Incorporating an economic analysis into any such studies would be enlightening. This economic analysis might usefully address the economic burden of morbidity upon survivors of colorectal cancer as well as the cost effectiveness of any proposed interventions. Limited evidence is available on the ability of quality of life to predict survival in colorectal cancer patients, in part again 2003 VOL. 27 NO. 1 because of the methodological limitations of existing studies. A multitude of confounding factors, such as the stage and site of the tumour and the treatment received, will have an impact on both quality of life and survival. Of the five studies5,9,13,21,45 identified in the literature over the past 20 years that dealt with the prognostic value of quality of life and its component dimensions for colorectal cancer, only two were prospective,21,45 while the other three5,9,13 were cross-sectional studies that obtained survival data at a later point and performed retrospective survival analyses. None of the above studies involved a sample of more than 200 colorectal cancer patients. While four of the studies controlled for the potential confounding effect of stage,9,13,21,45 only two controlled for treatment type, age and other demographic characteristics.13,21 The prognostic value of quality of life in colorectal cancer clearly emerges as an area for further detailed investigation, on a prospective basis and with the simultaneous measurement of and adjustment for potential confounders. Although a number of factors including demographic and disease characteristics, time since diagnosis, social support and physical activity have been identified as predictors or correlates of quality of life in colorectal patients, it is difficult to integrate these findings into a coherent framework, mainly due to the inability to compare across studies, their methodological limitations and the absence of a theoretical basis for modelling predictors of quality of life. Theoretical frameworks such as stress and coping theory52 have been found to have utility in predicting quality of life in other chronic illnesses53 and may inform future investigation of potential determinants of quality of life and subsequent supportive interventions for colorectal cancer patients. Quality of life and colorectal cancer, in terms of burden of disease, presents as a priority area for public health research. A comprehensive understanding of the issues surrounding quality of life and its determinants in survivors of colorectal cancer, including the impact of the disease on patients and their families, would make a significant contribution to reducing the escalating burden of this disease within our community

Journal

Australian and New Zealand Journal of Public Health – Wiley

Published: Feb 1, 2003

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