Prognostic significance of capsular invasion and capsular penetration in patients with clinically localized prostate cancer undergoing radical prostatectomy.

One hundred thirty patients with an observed follow-up of more than 10 years after radical prostatectomy were restaged with regard to local extent of the tumor in relation to the prostate capsule. Of 112 patients with surgically staged negative pelvic lymph nodes, 62 had a tumor-free prostate capsule, 24 had capsular invasion without penetration, and 26 had tumors extending through the capsule of the prostate. Observed overall and disease-free 10-year-survival rates were 79% and 69.4%, respectively, in patients with absence of capsular involvement and 70.8% and 66.7%, respectively, in patients with capsular invasion alone. In patients with capsular penetration, however, the survival rates significantly decreased to 57.7% (P = 0.018) and to 38.5 (P = 0.017), respectively. The overall progression rate was found to be significantly higher in patients with tumors extending through the prostatic capsule (46.2%), as compared to those with absence of capsular involvement (21%; P = 0.014) as well as to those with capsular invasion alone without penetration (25%; P = 0.034). Thus, in contrast to capsular invasion alone, capsular penetration means a poor prognostic indicator, which accounts for a reduced survival expectancy and a higher progression rate following radical prostatectomy. Therefore, tumors with capsular invasion and those with capsular penetration should not be grouped together in the same tumor stage as done in the 1987 edition of the TNM tumor classification system.