The prognostic significance of capsular incision (CapI) into tumor during radical prostatectomy (RP) with otherwise organ-confined disease remains uncertain.

To evaluate the impact of CapI into tumor on oncologic outcome.

A retrospective review of 8110 consecutive patients with prostate cancer treated at Ottawa Hospital and at Memorial Sloan-Kettering Cancer Center, both tertiary academic centers, between 1985 and 2008.

All patients underwent an open, laparoscopic or robotic RP.

Patients were divided into four pathologic categories: group 1 (CapI group), positive surgical margins (PSMs) without extraprostatic extension (EPE); group 2, negative surgical margins (NSMs) without EPE; group 3, NSM with EPE; group 4, PSMs with EPE. Estimates of recurrence-free survival were generated with the Kaplan-Meier method. Recurrence was defined as a prostate-specific antigen (PSA) >0.2 ng/ml and rising. Cox proportional hazards regression was used to estimate the hazard ratio (HR) for recurrence controlling for pretreatment PSA, RP date, RP Gleason sum, seminal vesicle invasion, and lymph node involvement. Pathologic categories were defined in the model by including the variables EPE and surgical margins (SMs) as well as their interaction.

Median follow-up was 37.3 mo. The 5-yr recurrence-free probability after RP for the CapI group was 77% (95% confidence interval [CI], 72-83). This was not only inferior to patients with NSMs and no EPE (log rank p<0.0001) but also to those with NSMs and EPE (log rank p=0.0002). In multivariate analysis the interaction between EPE and SM was not significant (p=0.26). In the adjusted model excluding the interaction term, patients with EPE had an increased risk for recurrence (HR: 1.80; 95% CI, 1.49-2.17; p<0.0001) as did those with positive margins (HR: 1.81; 95% CI, 1.51-2.15; p<0.0001). This was a retrospective study.

CapI into tumor has a significant impact on patient outcome following RP. Patients, who otherwise would have organ-confined disease, will now have a higher probability of recurrence than those with completely resected extraprostatic disease.