Tumor volume, surgical margin, and the risk of biochemical recurrence in men with organ-confined prostate cancer

Abstract

ObjectivesWe proposed to investigate predictors of biochemical recurrence (BCR) in pT2 prostate cancer by identifying the interrelationship between the tumor volume and surgical margin status, and their impact on recurrence. Materials and methodsClinical, pathologic, and follow-up data of 404 consecutive patients who were treated with radical prostatectomy alone and were diagnosed as pT2 prostate cancer in our institution were reviewed. Percent tumor volume (PTV) was estimated from the cancer distribution map, and the surgical margin status was reviewed by a single pathologist (JYR). Clinicopathologic variables were analyzed with respect to the risk of BCR. Results and limitationsRecurrence was observed in 39 (9.7%) patients at a mean of 28.9 (5–47) months. Preoperative PSA, biopsy Gleason score, surgical Gleason score, PTV, and surgical margin status were significantly related to BCR in univariate analysis; in multivariate analysis, PTV (P < 0.001) and surgical Gleason score (P = 0.021) were independent predictors of BCR. PTV was also an independent determinant of positive surgical margin (P = 0.035, HR 1.026, 95% CI 1.002–1.050). By combining the 2 predictors 5-year recurrence-free survivals for PTV ≤ 14.5% and surgical Gleason score ≤ 7, PTV >14.5% or surgical Gleason score > 7, and PTV > 14.5% and surgical Gleason score > 7 were 97.5%, 88.7%, and 44.5%, respectively (log-rank test, P < 0.01). Retrospective study nature, use of PTV instead of actual volume, and intermediate follow-up length are the main limitations of the study. ConclusionsIn men with pT2 prostate cancer, percent tumor volume and the surgical Gleason score were independently prognostic of BCR and by combining the 2 factors, risk of BCR could be significantly stratified. Tumor volume further determined surgical margin status undermining its prognostic value as an independent variable.