[Combined external radiotherapy and hormone therapy in patients with locally advanced prostate cancer: predictive factors of genitourinary toxicity]

Abstract

Introduction: Radiotherapy and androgen deprivation are an established treatment option for locally advanced prostate cancer. We evaluate outcomes in efficacy and toxicity for patients treated with this combined therapy at our institution.

Methods: A retrospective study of 80 patients with locally advanced prostate cancer treated with radiotherapy combined with neo-adjuvant (2 months) and adjuvant (24 months) androgen deprivation. We studied the clinical variables and side effects. We evaluated treatment outcomes using PSA nadir and biochemical failure, and recorded acute and late gastrointestinal and urinary toxicity. We assessed the correlation between clinical variables and urinary toxicity by means of univariate and multivariate analyses (multiple logistic regression).

Results: The mean patient age was 68 ± 5.81 years; the initial PSA was 20.05 ± 16.27 ng/ ml and the mean prostate volume 43.7 ± 27.57 cc. The clinical stage was T3a in 33% and T3b in 66%. The Gleason score was <7 in 39%, 7 in 46% and ≥8 in 15%. The mean follow-up was 44.4 months and biochemical failure was observed in 3 cases. Acute urinary toxicity was recorded in 90% of the patients (chronic in 35%) and acute gastrointestinal toxicity in 75% (late in 32%). In a univariate analysis, prostate volume and urinary symptoms were statistically correlated to acute and late urinary toxicity. Both prostate volume and urinary symptoms were independently associated with an increase in urinary toxicity in the logistic regression analysis.

Conclusions: Hormone-radiotherapy is a valid option to locally treat advanced prostate cancer with optimal short-term outcomes, although it is not devoid of side effects. Prostate volume and urinary symptoms before treatment can predict genitourinary toxicity.