Radical prostatectomy and positive surgical margins: tumor volume and Gleason score predicts cancer outcome

Introduction: positive surgical margins (PSMs) are common adverse factors to predict the outcome of a patient submitted to radical prostatectomy (PR). However, not all of these men will follow with biochemical (BCR) or clinical (CR) recurrence. Relationship between PSMs with these recurrent events has to be correlated with other clinicopathological findings in order to recognize more aggressive tumors in order to recommend complementary treatment to these selected patients. Materials and methods: we retrospectively reviewed the outcome of 228 patients submitted to open retropubic RP between March 1991 and June 2008, where 161 had and 67 did not have PSMs. Minimum follow-up time was considered 2 years after surgery. BCR was considered when PSA ≥ 0.2 ng/ml. CR was determined when clinical evidence of tumor appeared. Chi-square test was used to correlate clinical and pathologic variables with PSMs. The estimated 5-year risk of BCR and CR in presence of PSMs was determined using the Kaplan-Meier method and compared to log-rank tests. Results: from the total of 228 patients, 161 (71%) had PSMs, while 67 (29%) had negative surgical margins (NSMs). Prostatic circumferential margin was the most common (43.4%) site. Univariate analysis showed statistically significant (p < 0.001) associations between the presence of PSMs and BCR, but not with CR (p = 0.06). Among 161 patients with PSMs, 61 (37.8%) presented BCR, while 100 (62.8%) did not. Predicting progression-free survival for 5 years, BCR was correlated with pathological stage; Gleason score; pre-treatment PSA; tumor volume in specimen; capsular and perineural invasion; presence and number of PSMs. RC correlated only with angiolymphatic invasion and Gleason score. Considering univariate analyses the clinicopathological factors predicting BCR for 5 years, results statistically significant links with prostate weight; pre-treatment PSA; Gleason score; pathological stage; tumor volume; PSMs; capsular and perineural invasion. Multivariate analysis, otherwise, evidence only Gleason score and percentage of tumor volume more than 20% of total specimen volume, as significant independent predictors of BCR. Conclusion: In univariate analyses, presence, number and localization of PSMs have consistent correlation with BCR following RP but on follow-up BCR occurred only in 38% of our patients with PSMs. In multivariate analyses, percentage tumor volume and Gleason score in the surgical specimen were the significant risk factors for BCR. Angiolymphatic invasion and Gleason score were significantly correlated with CR. (author)