To analyze the biochemical failure rate and its predictive factors after radical prostatectomy (RP) in patients with high-risk localized prostate cancer.

The data of 166 patients with high-risk localized prostate cancer who underwent RP surgery in Peking university cancer hospital from January 2015 to November 2021 were retrospectively reviewed. The average age was 65.4±6.2 years old, and the average body mass index (BMI) was 24.86±3.23 kg/m². The median prostate-specific antigen (PSA) was 19.84 (10.98, 44.47) ng/ml, PSA density was 0.68 (0.34, 1.32)ng/ml², and prostate volume was 31.20 (25.58, 40.23) ml. Biopsy pathology Gleason score according to the International society of Urological Pathology(ISUP) grade group: 18 cases of group 1, 33 cases of group 2, 30 cases of group 3, 51 cases of group 4, and 33 cases of group 5, 1 case was unknown. The percentage of puncture positive needles was (55.4±25.7)%, and the largest linear length of positive lesions was 80.0% (60.0%, 90.0%). Preoperative clinical stage : 14 cases in ≤T_2b stage, 117 cases in T_2c stage, 13 cases in T_3a stage and 22 cases in ≥T_3b stage; 157 cases in N₀ stage, 9 cases in N₁ stage. One hundred and three patients (62.0%) were assessed by traditional imaging and 63(38.0%) were assessed by PSMA PET-CT. The patients underwent laparoscopic radical prostatectomy. 64 patients (38.6%) received neoadjuvant therapy, including 37 received neoadjuvant therapy for 1-3 months, 23 for 4-6 months and 4 for over 6 months. The postoperative pathological characteristics, treatment and prognosis of the patients were analyzed. The primary endpoint was biochemical failure, including biochemical persistence(BCP, defined as PSA≥0.1ng/ml at 4-6 weeks after operation, and confirmed by re-examination at least 1 week interval) and biochemical recurrence(BCR, PSA falling below 0.1ng/ml after operation and then rising ≥0.2 ng/ml without adjuvant therapy or after the end of adjuvant treatment).

Compared with preoperative clinicopathological characteristics, 48(28.9%) cases had postoperative pathological ISUP upgrade, 98 (59.0%)cases had T stage upgrade, and 13 (7.8%) cases had N stage upgrade. The rate of positive margins was 53%, and apex margin was the most common positive site (65.9%). The postoperative PSA in 114 patients (68.7%) decreased to less than 0.1ng/ml, of which 74 patients didn't receive the therapy and 40 patients received adjuvant therapy. 52 patients (31.3%) had postoperative PSA more than 0.1ng/ml and among them, 51 cases received salvage treatment. 5 patients (3.0%) underwent PSA progression during adjuvant or salvage endocrine therapy and were considered to have castration resistance. After a median follow-up time of 25.5 (12.0, 40.0) months, 78 patients (48.4%, 78/161) experienced biochemical failure, including 49 BCP and 29 BCR, the median time of biochemical failure was 30.0 (95% CI 14.5-45.5) months. Adjuvant therapy could reduce the rate of BCR (31.1% and 15.8%, P=0.08). Baseline PSA, PSA density, proportion of pathological ISUP ≥4, proportion of pathological T stage ≥T_3a, adjuvant therapy, and positive surgical margins were significantly associated with biochemical failure (P=0.034, 0.002, 0.004, 0.025, <0.001and 0.047). Multivariate Cox regression analysis showed that adjuvant therapy (P<0.001, OR=0.12), PSA density (P=0.03, OR=1.19) and positive surgical margins (P=0.034, OR=1.80) were independent factors for biochemical failure.

Patients with high-risk localized prostate cancer have a high rate of biochemical failure after RP and need to receive RP-based multimodal therapy. Adjuvant therapy, PSA density and positive surgical margins are independent factors associated with postoperative biochemical failure.

Prostatic neoplasms; Carcinoma; High-risk; Localized; Radical prostatectomy; Biochemical failure; Biochemical recurrence