Patient reported outcomes for quality of life (QOL) by Expanded Prostate Cancer Index (EPIC) on average 15 years post treatment

•Reported here are patient reported outcomes to 15.8 median years of follow up for initial therapy including brachytherapy, external beam radiotherapy, and radical prostatectomy.•Differences within each domain across modalities differences were generally preserved beyond 6 years of follow up.•Limited changes in quality of life over time suggest that shorter interval changes are largely representative of persistent changes in quality of life.•Costly and time consuming reporting of long term quality of life beyond 2–5 years may be limited value in future studies.