Health-related quality of life in men with localized prostate cancer treated with radiotherapy: validation of an abbreviated version of the Expanded Prostate Cancer Index Composite for Clinical Practice in Spain

BACKGROUND: Health-related quality of life (HRQoL) is greatly affected by prostate cancer (PCa) and associated treatments. This study aimed to measure the impact of radiotherapy on HRQoL and to further validate the Spanish version of the 16-item Expanded Prostate Cancer Index Composite (EPIC-16) in routine clinical practice. METHODS: An observational, non-interventional, multicenter study was conducted in Spain with localized PCa patients initiating treatment with external beam radiotherapy (EBRT) or brachytherapy (BQT). Changes from baseline in EPIC-16, University of California-Los Angeles Prostate Cancer Index (UCLA-PCI), and patient-perceived health status were longitudinally assessed at end of radiotherapy (V2) and 90 days thereafter (V3). Psychometric evaluations of the Spanish EPIC-16 were conducted. RESULTS: Of 516 patients enrolled, 495 were included in the analysis (EBRT, n = 361; BQT, n = 134). At baseline, mean (standard deviation [SD]) EPIC-16 global scores were 11.9 (7.5) and 10.3 (7.7) for EBRT and BQT patients, respectively; scores increased, i.e., HRQoL worsened, from baseline, by mean (SD) of 6.8 (7.6) at V2 and 2.4 (7.4) at V3 for EBRT and 4.2 (7.6) and 3.9 (8.2) for BQT patients. Changes in Spanish EPIC-16 domains correlated well with urinary, bowel, and sexual UCLA-PCI domains. EPIC-16 showed good internal consistency (Cronbach’s alpha = .84), reliability, and construct validity. CONCLUSION: The Spanish EPIC-16 questionnaire demonstrated sensitivity, strong discriminative properties and reliability, and validity for use in clinical practice. EPIC-16 scores worsened after radiotherapy in different HRQoL domains; however, a strong tendency towards recovery was seen at the 3-month follow-up visit. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12955-021-01856-z.