Effect of Postoperative Nadir PSA and Period until Nadir PSA on Biochemical Recurrence in Patients with Negative Surgical Margins at Pathological T2 Stage Following Radical Prostatectomy

Abstract

Background: The surgical treatment radical prostatectomy (RP) is an effective treatment for limited prostate cancer. However, some patients experience biochemical recurrence (BCR) after surgery, leading to disease recurrence. The aim of this study is to investigate the relationship between a series of clinical indicators, including postoperative nadir prostate-specific antigen (PSA), the period until nadir PSA, and BCR in pathological T2 stage (pT2), negative surgical margins (NSM) patients, with the goal of identifying the high-risk population of BCR in these patients and promptly intervening clinically. Methods: A retrospective study was conducted on 119 patients admitted to our hospital, between October 2015 and December 2020, for RP with pT2 pN0, NSM and no prior use of neoadjuvant chemotherapy or endocrine therapy, and no history of other malignancies. PSA levels were initially measured one month after surgery, followed by weekly checks from one to seven months and monthly checks thereafter. PSA can be detected at PSA >0.01 ng/mL. BCR was defined as two consecutive postoperative PSA ≥0.2 ng/mL or a postoperative nadir PSA ≥0.2 ng/mL. Patients were monitored for BCR for three years following surgery. The prognostic model for BCR after RP was established by univariate and multifactorial analysis through the Cox proportional hazards model. Kaplan-Meier analysis was used to plot the BCR-free rate curves. Results: During the three years of follow-up, a total of 57 of 119 patients (48.7%) experienced BCR. In univariate analysis, pathological Gleason score (≤3+4 vs ≥4+3, p < 0.001), pathological maximum tumor diameter (p = 0.035), postoperative nadir PSA (≤0.01 ng/mL vs >0.01 ng/mL, p < 0.001), and period until nadir PSA (≤60 days vs >60 days, p < 0.001) were all associated with postoperative BCR. In contrast, only postoperative nadir PSA (p < 0.001) and the period until nadir PSA (p = 0.05) had statistically significant differences in multifactorial analysis and were independent risk factors for postoperative BCR in pT2 and NSM patients. Conclusions: In this paper, we point out that in pT2 and NSM patients, both had a detectable postoperative PSA minimum (>0.01 ng/mL) and a longer PSA decline (>60 days) increasing the risk of BCR.