Predictors of Progression to Castration-resistant Prostate Cancer After Radical Prostatectomy in High-risk Prostate Cancer Patients.

Background/aim: To examine the specific time frame and identify associated risk factors from commencement of hormonal therapy to the onset of castration-resistant prostate cancer among patients who have developed biochemical recurrence following radical prostatectomy.

Patients and methods: We retrospectively reviewed the records of 92 patients who developed biochemical recurrence and received hormonal therapy as initial salvage treatment after radical prostatectomy for high-risk localized prostate cancer from 2005 to 2021. The castration-resistant prostate cancer-free survival rates from the commencement of salvage hormonal therapy were analyzed using log-rank methods. Cox proportional hazard regression was performed to analyze the risk factors associated with acquiring castration resistance. The patients were stratified based on those risk factors.

Results: During a median follow-up duration of 57 months, 24 (26.1%) patients developed castration-resistant prostate cancer. The 5- and 10-year castration-resistant prostate cancer-free survival rates were 73.6% and 54.5%, respectively. A multivariate analysis showed that Grade Group of 5 and prostate-specific antigen doubling time at biochemical recurrence of ≤3 months were independent predictors of castration-resistant prostate cancer. The 5-year castration-resistant prostate cancer-free survival rates in the low- and high-risk groups, stratified according to the aforementioned factors, were 85.4% and 47.6%, respectively.

Conclusion: Patients in high Grade Group and short prostate-specific antigen doubling time after radical prostatectomy are more likely to develop resistance to salvage hormonal therapy.