Prognostic value of seminal vesicle involvement due to prostate cancer in radical prostatectomy specimens

To study the influence, in terms of prognosis, of the finding of seminal vesicle involvement in patients with prostate adenocarcinoma treated with radical prostatectomy.

We reviewed a series of patients with seminal vesicle involvement with clinically localized prostate adenocarcinoma who underwent radical prostatectomy between 1989 and 2009, focusing on their clinical-pathological characteristics, biochemical progression-free survival (BPFS) and specific survival (SS). We assessed the variables that influenced BPFS and designed a risk model.

A total of 127 out of 1,132 patients who underwent surgery (11%) presented seminal vesicle invasion (i.e., pT3b). In the multivariate study of the entire series (Cox model), pT3b affects the BPFS (HR: 2; 95% CI: 1.4-3.3; P=.001). Other influential factors were the affected borders, initial prostate-specific antigen levels, pathological Gleason score and the presence of palpated tumor. The pT3b tumors have poorer clinical-pathological variables when compared with pT2 and pT3a tumors. Sixty-five percent of the patients evidenced biochemical progression. The BPFS was significantly poorer for pT3b (40 ± 4% and 28 ± 4% at 5 and 10 years, respectively) than for pT2 and pT3a (P<.0001). The SS was also poorer in patients with pT3b tumors (91 ± 2% and 76 ± 4% at 5 and 10 years, respectively) (P<.0001). The predictors within the pT3b patient group were: PSA levels >10 ng/mL (HR: 1.9; 95% CI: 1.04-3.6; P=.04) and pathological Gleason score 8-10 (HR: 2.1; 95% CI: 1.2-3.5; P=.03). We designed a risk model that accounts for the variables involved, which entails 2 groups with different BPFS (P=.004): Group 1 (0-1 variable), with a BPFS of 46 ± 7% and 27 ± 8% at 5 and 10 years, respectively; and Group 2 (2 variables), with a BPFS of 14 ± 7% and 5 ± 5% at 5 and 10 years, respectively.

Seminal vesicle involvement severely and negatively affects the BPFS and SS. We designed a risk model with the independent influential variables in BPFS (pathological Gleason score 8-10 and PSA levels >10 ng/mL). This model confirms that pT3b tumors are a heterogeneous group, which includes an important group with better prognosis when surgical treatment is performed.