Cumulative incidence and predictive factors of radiation cystitis in patients with localized prostate cancer.

PURPOSE: To determine the cumulative incidence of overall and severe radiation cystitis in a high volume cohort of patients and to investigate its potential predictive factors.

METHODS

We have performed a retrospective analysis of clinical data from patients diagnosed with localized prostate cancer and treated with radiotherapy at our institution (June 2005-January 2013), and quantified the cumulative incidence of radiation cystitis. Cox regression analysis and Kaplan-Meier curves were computed to evaluate the determinants of radiation cystitis.

RESULTS

Data from 783 patients was retrieved (557 treated with primary radiotherapy, 188 with adjuvant and 38 with salvage). Median follow-up time was 49 months (P25-P75: 31.8-69.3). At 5 years of follow-up, cumulative incidence of overall and severe radiation cystitis was 9.1 and 1.6%, respectively. No association was found between the incidence of radiation cystitis and age, tumor T stage, baseline PSA level, Gleason score, D'Amico risk classification, radiotherapy setting (primary versus adjuvant versus salvage) or radiation dose applied.

CONCLUSIONS

Within our cohort, radiation cystitis is an uncommon complication of prostatic radiotherapy treatment, and severe cases requiring hospitalization are even more infrequent. We found no association between tumor characteristics, radiotherapy setting or radiation dose and the cumulative incidence of radiation cystitis.