Type of patients in whom biochemical recurrence after radical prostatectomy can be observed without salvage therapy

Purpose: To examine the prognosis after BCR with and without salvage therapy, including radiation and/or androgen deprivation. Methods: The study population consisted of 431 patients, all of whom underwent radical prostatectomy and developed BCR (PSA > 0.2 ng/mL). According to the two risk factors [Gleason score ≥ 8 and PSA-doubling time (DT) < 6 months], we divided the patients into two groups. The high/intermediate-risk group consisted of patients with both or one risk factor. On the other hand, patients with neither factor were in the low-risk group. We set the starting point at the timing of BCR, and the endpoints were development to castration-resistant prostate cancer (CRPC) and cancer-specific death. Results: During the mean follow-up period of 8.3 years after BCR, CRPC was observed in 49 patients (11.4%), and 21 patients (4.9%) died due to prostate cancer. We first divided the 191 high/intermediate-risk patients according to the PSA level (PSA < 1.0 ng/mL, PSA 1.0–4.0, and PSA > 4.0 or no therapy) at the initiation of salvage therapy, including radiation and/or androgen deprivation. We found that delayed (PSA > 4.0 ng/mL) or no salvage therapy was significantly associated with CRPC and cancer-specific death. In the 240 low-risk patients, Kaplan–Meier curves demonstrated no significant difference in CRPC-free survival or cancer-specific survival within 10 years from the timing of BCR. Conclusions: Observation after BCR without salvage therapy or delayed administration may be an option for low-risk patients with a Gleason score ≤ 7 and PSA-DT ≥ 6 months when their life expectancy is within 10 years.