Prognostic factors of salvage radiotherapy after radical prostatectomy / 中华泌尿外科杂志

ABSTRACT

Objective:To investigate the prognosis after salvage radiotherapy with or without hormone therapy for prostate cancer.Methods:From May 2014 to December 2020, 248 patients undergoing salvage radiotherapy due to prostate-specific antigen (PSA)persistence or biochemical progression after radical prostatectomy at Sun Yat-sen University Cancer Center (n=157) and West China Hospital, Sichuan University (n=91) were analyzed. Median age was 66 (45-78) years old. Median PSA was 23.50 (0.18-845.00) ng/ml. The number of PSA persistence and biochemical progression were 143 (59%) and 105 (42%). The number of pT 2, pT 3a, pT 3b, pT 4, and unknown T stage was 99, 49, 78, 15 and 7 cases.The number of N 0, N 1 and unknown N stage was 153, 44 and 51 cases. 165 cases had positive surgical margin. Gleason score of 6, 7, 8, >8 score and unknown was in 12, 104, 34, 90 and 8 patients. Early and late salvage radiotherapy was performed in 117 and 131 patients, and 70 patients (28%) were CRPC. Hormone therapy was used combined with radiotherapy in 182 patients (73%). PSA decline after radiotherapy was compared with Chi-squre test. Kaplan-Meier method and log-rank test were used to compare progression free-survival (PFS)after radiotherapy. Univariate and multivariate analyses of PFS were performed using Cox proportional hazards model. Early salvage radiotherapy was defined as PSA≤0.5 ng/ml before radiotherapy, and late salvage radiotherapy was defined as PSA>0.5ng/ml. Results:PSA response (PSA decline ≥50%) rate was 94% (233/248), and 82% (203/248) patients had PSA decline ≥ 90%. Twelve (5%) patients had rising PSA after completing radiotherapy, but only 4 (2%) had real progression. The median PFS was 69 months (95% CI 68-70), and 3-year and 5-year PFS rate were 80% and 67%. PFS of PSA persistence and biochemical progression were similar ( HR =0.71, 95% CI 0.37-1.37, P=0.311). Compared with late salvage radiotherapy, early salvage radiotherapy had better PFS [69 (95% CI 68-70) vs. 59 (95% CI 44-74) months, P<0.001]. Compared with hormone sensitive, castration-resistant was associated with worse PFS (5-year PFS rate 74% vs. 51%, P<0.001). In multivariate analysis, Gleason score>8, castration-resistant and late salvage radiotherapy were unfavorable prognostic factors. Conclusions:In patients receiving salvage radiotherapy with or without hormone therapy for PSA persistence and biochemical progression after radical prostatectomy, high PSA level before radiotherapy and castration resistant is associated with poor prognosis.