A new study reports the 5-year patient-reported outcome data from a population-based cohort of men with localized prostate cancer. These findings in conjunction with data on survival, treatment burden and treatment cost can assist clinicians in explaining to newly diagnosed patients the likely effects of modern management options on quality of life.
Refers to Hoffman K. E. et al. Patient-reported outcomes through 5 years for active surveillance, surgery, brachytherapy, or external beam radiation with or without androgen deprivation therapy for localized prostate cancer. JAMA 323, 149–163 (2020).
Optimal management of localized prostate cancer involves consideration of patient and clinical risk factors, as well as patient preferences. Given the high survival for localized disease (approaching 100% at 5 years1), the long-term effects of management strategies on health-related quality of life (HRQOL) are important considerations. People value information about how cancer and its management might affect their day-to-day functioning and HRQOL. This information requires rigorous collection, analysis, interpretation and application of high-quality data obtained using validated patient-reported outcome measures (PROMs).
A patient-reported outcome (PRO) is a direct report from a patient about the effect of disease or treatment that has not been interpreted by anyone else. PROMs can be used to assess the severity or bother of disease symptoms and adverse effects of treatment and also the effect that these factors have on function (such as physical, emotional, social and role function) and overall HRQOL. High-quality, comprehensive PRO studies can provide evidence about the benefits and harms of treatment from the perspective of the patient2. PRO data are particularly useful because certain issues are otherwise not always observable, for example, pain. In prostate cancer research, some commonly used PROMs include the Expanded Prostate Index Composite-26 (EPIC-26), the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLQ-C30) and prostate cancer module (QLQ-PR25) and the Functional Assessment for Cancer Therapy Prostate cancer module (FACT-P).
A recent population-based cohort study of 2,005 men with localized prostate cancer published in JAMA is particularly informative3. Men from five Surveillance, Epidemiology and End Results programme registries and the observational Cancer of the Prostate Strategic Urologic Research Endeavor registry between 2011 and 2012 were included and followed for a median of 73 months3. Participants were categorized into two groups for analysis according to clinical risk: favourable risk (clinical stage cT1 to cT2bN0M0, PSA ≤20 ng/ml, or Grade Group 1–2 (n = 1,386)) and unfavourable risk (clinical stage cT2cN0M0, PSA of 20–50 ng/ml, or Grade Group 3–5 (n = 619)), and then according to the primary treatment received after diagnosis. Among the participants with favourable-risk disease, the treatment groups were nerve-sparing prostatectomy (n = 675), external beam radiotherapy (EBRT; n = 261), low-dose brachytherapy (n = 87) and active surveillance (AS; n = 363).
Among those with unfavourable-risk disease, participants received either EBRT with androgen deprivation therapy (ADT; n = 217) or prostatectomy (n = 402). Participants included in the analysis completed PRO questionnaires at baseline and at one or more of their follow-up assessments at 6 months, 1 year, 3 years and 5 years after treatment3. The EPIC-26 questionnaire was used to assess sexual function, urinary incontinence, urinary irritation, bowel function and hormonal function. The Medical Outcomes Study Short Form-36 (SF-36) was used to assess physical function, emotional wellbeing, energy and fatigue. Scores from the EPIC-26 and SF-36 range from 0 to 100, with high scores indicating improved functioning. Both of these PROMs have extensive evidence of validity and reliability in prostate cancer research4,5.
A major strength of this study3 is that changes in PRO scores over time and differences between groups were interpreted according to their clinical significance on the basis of published values for minimal clinically important differences (MCIDs), in addition to their statistical significance. A MCID is the smallest difference in PRO scores (longitudinally or cross-sectionally) that is considered important to a patient. Methods for establishing MCIDs can be categorized as distribution-based, in which the change is considered meaningful if the magnitude of difference exceeds statistical criteria of variability (for example, half a standard deviation)6; or anchor-based, in which actual changes in a correlated, reliable, external indicator of change (for example, patient ratings of change or clinicians’ ratings of Karnofsky Performance Status) are mapped to changes in questionnaire scores6. The ideal method is to use both approaches, as was done to establish MCIDS for the EPIC-26 (ref.7) and SF-36 (ref.8) in prostate cancer.
Among men with favourable-risk prostate cancer, Hoffman and colleagues3 found that sexual function up to 24 months and urinary incontinence up to 5 years were worse in those managed with prostatectomy than in those who received EBRT, brachytherapy or AS. Men who had brachytherapy experienced the worst urinary irritation and bowel function in the first year, which then improved to levels similar to those in other treatment groups at 5 years. Bowel function and urinary irritation were minimally affected in all other groups. All treatment groups experienced clinically meaningful declines in sexual function from baseline up to 5 years, with the worst sexual function at 5 years in those treated with EBRT. Scores for hormonal function were high throughout, with no differences between treatment groups. Only one prostate cancer-related death occurred among the 1,386 men in the favourable-risk group. Of the men managed with AS, 25% subsequently had definitive treatment with radiation or surgery and had worse functional outcomes at 5 years than men who remained on AS. Men treated with EBRT and AS were older and had more comorbidities at baseline than those managed with prostatectomy or brachytherapy3.
Among men with unfavourable-risk prostate cancer, those managed with EBRT plus ADT were older and had more baseline comorbidities than those who underwent prostatectomy. Men who received EBRT plus ADT reported fewer problems with incontinence at all time points (statistically and clinically) than men who underwent prostatectomy, after adjusting for differences at baseline. No differences were observed in urinary irritation, which remained fairly stable over 5 years in both groups. Bowel and hormonal function were better following prostatectomy than EBRT plus ADT throughout the 5 years, but the differences were only clinically significant in the first year. Sexual function declined steeply from baseline to 6 months with EBRT plus ADT and prostatectomy, and remained low thereafter. Of men who could maintain an erection sufficient for intercourse at baseline, the proportions who could maintain an erection at 5 years were 31% after prostatectomy and 46% after EBRT plus ADT. No difference was observed between these two treatments in sexual bother at 5 years, even though scores at 5 years for sexual function were worse for prostatectomy than EBRT plus ADT. Only 8 prostate cancer-related deaths occurred among the 619 men with unfavourable-risk prostate cancer3.
Baseline physical function was higher among those who underwent prostatectomy than EBRT in both favourable-risk and unfavourable-risk groups. Scores for all other SF-36 domains were similar up to 5 years for all management approaches3. However, the SF-36 scale for emotional well-being is general in nature and might not be ideal for assessing anxiety and fear of cancer progression associated with managing localized prostate cancer.
“These data … are directly relevant to clinical consultations with newly diagnosed patients”
These data from Hoffman et al.3 are particularly valuable because they compare the quality of life profiles of men treated with contemporary treatment options and are, therefore, directly relevant to clinical consultations with newly diagnosed patients who are deciding on appropriate management strategies.
“These findings will assist clinicians in explaining … the adverse effects … of modern treatment options”
These findings will assist clinicians in explaining and quantifying the adverse effects and functional implications of modern treatment options. This information is vital for men with localized prostate cancer who are weighing up the advantages and disadvantages of different approaches and deciding between them. Another important consideration is treatment burden, which includes the effect of the personal workload of health care (for example attending appointments, taking medication and other aspects of self-management) on patient function and well-being. High treatment burden is associated with poor adherence, increased burden on health-care systems and caregivers and poor health outcomes9, so it should be discussed before committing to a management option. Financial costs incurred by both the patient and health-care system should also be considered10. A comprehensive appraisal of management approaches is particularly important given that the survival outcomes were excellent and similar for all studied options.
Howlader, N. et al. SEER cancer statistics review (CSR)1975–2016. National Cancer Institute https://seer.cancer.gov/csr/1975_2016/ (2019).
Weiner, A. B. et al. Increasing incidence of metastatic prostate cancer in the United States (2004–2013). Prostate Cancer Prostatic Dis. 19, 395–397 (2016).
Hoffman, K. E. et al. Patient-reported outcomes through 5 years for active surveillance, surgery, brachytherapy, or external beam radiation with or without androgen deprivation therapy for localized prostate cancer. JAMA 323, 149–163 (2020).
McHorney, C. A., Ware, J. E. Jr & Raczek, A. E. The MOS 36-Item Short-Form Health Survey (SF-36): II. Psychometric and clinical tests of validity in measuring physical and mental health constructs. Med. Care 31, 247–263 (1993).
Szymanski, K. M. et al. Development and validation of an abbreviated version of the expanded prostate cancer index composite instrument for measuring health-related quality of life among prostate cancer survivors. Urology 76, 1245–1250 (2010).
Ousmen, A. et al. Distribution- and anchor-based methods to determine the minimally important difference on patient-reported outcome questionnaires in oncology: a structured review. Health Qual. Life Outcomes 16, 228 (2018).
Skolarus, T. A. et al. Minimally important difference for the expanded prostate cancer index composite short form. Urology 85, 101–105 (2015).
Jayadevappa, R. et al. Comparison of distribution- and anchor-based approaches to infer changes in health-related quality of life of prostate cancer survivors. Health Serv. Res. 47, 1902–1925 (2012).
Sav, A. et al. Burden of treatment for chronic illness: a concept analysis and review of the literature. Health Expect. 18, 312–324 (2015).
Sharma, V. et al. Cost-effectiveness of active surveillance, radical prostatectomy and external beam radiotherapy for localized prostate cancer: an analysis of the ProtecT trial. J. Urol. 202, 964–972 (2019).
M.R.S. has received support to his institution for research from Astellas Pharma, Celgene, Bayer, Bionomics, Medivation, Sanofi, Pfizer, AstraZeneca, Bristol-Myers Squibb, Roche, Amgen, Merck Sharp & Dohme and Tilray. He has also received travel, accommodations and expenses from Medivation/Pfizer. R.M.-B. declares no competing interests.
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Mercieca-Bebber, R., Stockler, M.R. Patient-reported outcomes and localized prostate cancer management. Nat Rev Urol 17, 257–258 (2020). https://doi.org/10.1038/s41585-020-0303-2