Pre-radiotherapy PSA progression is a negative prognostic factor in prostate cancer patients using 5‑alpha-reductase inhibitors

Abstract

Objective

To investigate the impact of 5‑alpha-reductase inhibitor (5-ARI) use on radiotherapy outcomes for localized prostate cancer.

Patients and methods

We included 203 patients on a 5-ARI from our institutional database comprising over 2500 patients who had been treated with either external beam radiotherapy (EBRT) or brachytherapy for localized prostate cancer. Patients received a 5-ARI for urinary symptoms or active surveillance. Cancer progressions at the time of definitive treatment were analyzed according to the following criteria: (a) progression of Gleason score or increase in cancer volume on biopsy, (b) first biopsy positive for cancer after being treated for urinary symptoms with a 5-ARI, and (c) prostate-specific antigen (PSA) progression with or without a previous cancer diagnosis. Biochemical failure (BF) was defined by the Phoenix definition. Log-rank test was used for survival analysis.

Results

At a median follow-up of 38.2 months (standard deviation 22.2 months), 10 (4.9%) patients experienced BF. Concerning prostate cancer progression criteria, 52% of men demonstrated none, 37% showed only one criterion, and 11% showed two. Using univariate analysis, PSA progression (p = 0.004) and appearance of a positive biopsy (p < 0.001) were significant predictive factors for BF, while Gleason progression (p = 0.3) was not. In multivariate analysis adjusted for cancer aggressiveness, rising PSA (hazard ratio, HR, 5.7; 95% confidence interval, CI, 1.1–28.8; p = 0.04) and the number of cancer progression factors (HR 2.9, 95% CI 1.2–7.0, p = 0.02) remained adverse risk factors.

Conclusion

PSA progression experienced during 5‑ARI treatment before radiotherapy is predictive of worse biochemical outcome. Such details should be considered when counseling men prior to radiation therapy.

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