Risk of Biochemical Recurrence and Metastasis in Prostate Cancer Patients Treated with Radical Prostatectomy After a 10-year Disease-free Interval.

Abstract

Background and objective: Prostate-specific antigen (PSA) testing is used to follow up prostate cancer (PCa) patients treated with radical prostatectomy (RP). Research on PSA thresholds for identifying PCa patients with biochemical recurrence (BCR) who are at a higher risk of progression yielded inconclusive results. This study aims to investigate the risk of late BCR in PCa patients treated with RP and long postoperative (120 mo) undetectable PSA follow-up, and to identify prognostic factors for late BCR within this patient cohort.

Methods: PCa patients treated with curative RP (1992-2012) and free of BCR during the first 120 mo following RP were retrospectively identified within five European tertiary centers; BCR was defined as two consecutive PSA values of ≥0.2 ng/ml. Kaplan-Meier and Cox regression models tested for an association between BCR and patient or tumor characteristics.

Key findings and limitations: The study cohort consisted of 4639 patients, of whom 243 (5.2%) developed BCR at a medium follow-up of 147 mo. Of those with BCR, 23 (9.5%) subsequently developed metastatic progression. In Kaplan-Meier models, BCR-free survival differed according to advanced tumor status. In multivariable Cox regression models, pT stage (pT3a: hazard ratio [HR]: 1.46; pT3b: HR: 2.42), pathological Gleason score (pGS 3 + 4: HR: 1.71; pGS ≥4 + 3: HR: 2.47), surgical margin (R1/Rx: HR: 1.72), and pNx stage (pNx: HR: 0.72) represented independent predictors for BCR (all p < 0.05). Conversely, age, PSA at diagnosis, and year of surgery failed to achieve independent predictor status for BCR.

Conclusions and clinical implications: Among PCa patients with an uneventful follow-up of at least 10 yr after RP, still one in 20 patients subsequently develop late BCR. Nevertheless, late BCR and subsequent progression to metastasis (0.3%) rates in patients with pT2 stage and pGS ≤3 + 4 were strikingly low, implicating that abandoning follow-up beyond an uneventful period of 10 yr is justifiable within this cohort of patients.

Patient summary: In this study, prostate cancer patients treated with a radical prostatectomy and at least 10 yr of uneventful prostate-specific antigen testing were identified within five European centers. Relying on these patients, the rate of subsequent late biochemical recurrence was calculated and risk factors were identified for biochemical recurrence following 10 yr of uneventful prostate-specific antigen testing.