Margin involvement at prostatectomy for clinically localized prostate cancer: does a low-risk group exist?

Abstract

Purpose: To determine whether additional pathology details may provide risk stratification for patients with involved surgical margins at radical prostatectomy (RP).

Methods and materials: Eligible patients underwent RP between 2003 and 2010. Patients with preoperative prostate-specific antigen (PSA) ≥20, follow-up <12 months, lymph node or seminal vesicle involvement, or who received radiation therapy or hormone therapy prior to PSA relapse were excluded. Surgical specimens were reviewed by a study pathologist, blinded to outcomes. Survival analysis methods were employed to assess disease control and survival rates, as well as association of patient-, tumor-, and treatment-specific factors for endpoints.

Results: Of 355 RP cases, 279 patients were eligible for the present analysis. At a median follow-up of 53 months (range, 16-127), 31/114 (27%) of patients with involved surgical margins experienced PSA relapse, as compared with 7/165 (4%) for negative margins (hazard ratio, 4.997; 95% confidence interval, 2.425-10.296; P < .0001). Detailed pathology review demonstrated associations between PSA relapse and Gleason score at RP, extent of margin involvement (width), capsule penetration, and perineural invasion. Subgroup analysis identified low risk (4%) of 5-year PSA relapse for patients with Gleason ≤6 mm and margin width ≤4 mm (single maximal or cumulative). All subgroups with higher Gleason score or wider margin were associated with >20% risk of PSA relapse at 5 years.

Conclusions: Within the present study, Gleason score, 6 patients with margin width ≤4 mm appear to have low rates of early PSA relapse following RP. Low-grade cases with larger extent of margin involvement or higher risk Gleason score patients with any margin involvement have high rates of early PSA relapse.