Quality of life in breast cancer patients: measurement issues in cancer clinical trials

Health-related quality of life in breast cancer patients: a bibliographic review of the literature from 1974 to 2007

Background

Quality of life in patients with breast cancer is an important outcome. This paper presents an extensive overview on the topic ranging from descriptive findings to clinical trials.

Methods

This was a bibliographic review of the literature covering all full publications that appeared in English language biomedical journals between 1974 and 2007. The search strategy included a combination of key words 'quality of life' and 'breast cancer' or 'breast carcinoma' in titles. A total of 971 citations were identified and after exclusion of duplicates, the abstracts of 606 citations were reviewed. Of these, meetings abstracts, editorials, brief commentaries, letters, errata and dissertation abstracts and papers that appeared online and were indexed ahead of publication were also excluded. The remaining 477 papers were examined. The major findings are summarized and presented under several headings: instruments used, validation studies, measurement issues, surgical treatment, systemic therapies, quality of life as predictor of survival, psychological distress, supportive care, symptoms and sexual functioning.

Results

Instruments-Several valid instruments were used to measure quality of life in breast cancer patients. The European Organization for Research and Treatment of Cancer Core Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and its breast cancer specific complementary measure (EORTC QLQ-BR23) and the Functional Assessment Chronic Illness Therapy General questionnaire (FACIT-G) and its breast cancer module (FACIT-B) were found to be the most common and well developed instruments to measure quality of life in breast cancer patients. Surgery-different surgical procedures led to relatively similar results in terms of quality of life assessments, although mastectomy patients compared to conserving surgery patients usually reported a lower body image and sexual functioning. Systemic therapies-almost all studies indicated that breast cancer patients receiving chemotherapy might experience several side-effects and symptoms that negatively affect their quality of life. Adjuvant hormonal therapies also were found to have similar negative impact on quality of life, although in general they were associated with improved survival. Quality of life as predictor of survival-similar to known medical factors, quality of life data in metastatic breast cancer patients was found to be prognostic and predictive of survival time. Psychological distress-anxiety and depression were found to be common among breast cancer patients even years after the disease diagnosis and treatment. Psychological factors also were found to predict subsequent quality of life or even overall survival in breast cancer patients. Supportive care-clinical treatments to control emesis, or interventions such as counseling, providing social support and exercise could improve quality of life. Symptoms-Pain, fatigue, arm morbidity and postmenopausal symptoms were among the most common symptoms reported by breast cancer patients. As recommended, recognition and management of these symptoms is an important issue since such symptoms impair health-related quality of life. Sexual functioning-breast cancer patients especially younger patients suffer from poor sexual functioning that negatively affect quality of life.

Conclusion

There was quite an extensive body of the literature on quality of life in breast cancer patients. These papers have made a considerable contribution to improving breast cancer care, although their exact benefit was hard to define. However, quality of life data provided scientific evidence for clinical decision-making and conveyed helpful information concerning breast cancer patients' experiences during the course of the disease diagnosis, treatment, disease-free survival time, and recurrences; otherwise finding patient-centered solutions for evidence-based selection of optimal treatments, psychosocial interventions, patient-physician communications, allocation of resources, and indicating research priorities were impossible. It seems that more qualitative research is needed for a better understanding of the topic. In addition, issues related to the disease, its treatment side effects and symptoms, and sexual functioning should receive more attention when studying quality of life in breast cancer patients.

Breast cancer management: quality-of-life and cost considerations

The purpose of this article was to provide a literature-based extensive overview of the quality-of-life and cost issues posed by the management of breast cancer. Incidence and mortality rates vary widely in different countries. Breast cancer accounts approximately for one-fifth of all deaths in women aged 40-50 years. The 1994-1998 incidence rate in the US population was on average 114.3 per 100 000 women. Treatment options include surgery, radiotherapy and drug therapy (cytotoxic and endocrine drugs). All treatment options affect patients' health-related quality of life (HR-QOL) in various ways. The use of cytotoxic agents has a particularly large HR-QOL impact. HR-QOL questionnaires are complex tools, not routinely used in breast cancer trials.Worldwide, around 10 million individuals develop cancer each year; this figure is expected to increase to 15 million in 2020. For all cancers, the total economic burden of this disease worldwide was projected by the authors to be in the range of $US 300-400 billion in 2001 (about $US 100-140 billion as direct costs and the remainder as indirect costs [morbidity and mortality]). According to the National Institute of Health (NIH), the total cost of cancer was estimated at $US 156.7 billion in 2001 in US ($US 56.4 billion as direct costs, $US 15.6 as indirect morbidity costs, and $US 84.7 billion as indirect mortality costs). Based on limited information, in the US, breast cancer can be projected to account for about one-fifth/one-fourth of the total cost of cancer. Breast cancer treatment costs are higher in the US than in other developed countries. Both direct and indirect costs are dependent on disease stage. The per-patient costs for initial care in 1992 were estimated at $US 10 813, for continuing care at $US 1084 and for terminal care at $US 17 886. Stage-specific costs provide information for cost-effectiveness analyses of cancer-control initiatives, such as screening programmes. Economic studies on breast cancer are heterogeneous, and the cost estimates made are not easily generalisable. The cost of treatment for breast cancer in developing countries is < or =5% of that in developed regions.

Quality of life in patients undergoing systemic therapy for advanced breast cancer

To date no published reviews have examined the effects of systemic therapy on health-related quality of life (HRQOL) in patients with advanced breast cancer. We did a systematic review identifying 19 randomised controlled trials, with 5732 participants. Most of the trials (12) involved chemotherapy, but six involved hormonal therapies, and one a biological therapy. 15 studies assessed HRQOL as a secondary endpoint; only seven reported any significant differences in HRQOL between treatment groups. We identified several limitations with methods. Most studies reported problems with withdrawal of patients, which reduces statistical power and can lead to bias. Baseline characteristics of patients were not reported in many cases, and only three studies examined clinical significance. We conclude that HRQOL data provide some invaluable insights into the treatment and care of patients, but future studies should address several common problems with methods. We propose some approaches to overcome these limitations and improve future study designs.