Prognostic significance of microscopic bladder neck invasion in prostate cancer.

OBJECTIVE

To assess the prognostic significance of microscopic bladder neck invasion (BNI+) after radical prostatectomy (RP).

PATIENTS AND METHOD: From January 1988 to December 2006, 1480 patients with clinically localized prostate cancer were surgically treated at one tertiary university hospital. The risk of biochemical progression, defined as a prostate-specific antigen (PSA) level after RP of >0.2 ng/mL, was assessed with univariate and multivariate analyses for clinical and pathological variables. We compared the biochemical progression-free survival (bPFS) of patients with BNI+ vs stages pT2, pT3a, pT3b and positive lymph nodes (N+). In a second analysis, we evaluated the bPFS of patients in different stages associated with BNI+ and compared them with those in the same stages with no BNI.

RESULTS

BNI+ was found in 132 (9%) patients; the 5-year bPFS was 86%, 54%, 26% and 10% for stages pT2, pT3a, pT3b and N+, respectively, while it was 30% for BNI+ (P < 0.001). There was no difference in the 5-year bPFS between stage pT2 and pT2 + BNI (P = 0.32). Stages pT3a and pT3b had a better 5-year bPFS than stage pT3a + BNI (P = 0.003) and pT3b + BNI (P = 0.001), respectively. In the univariate analysis all variables were associated with BP. In the multivariate analysis, only BNI+ had no association with BP (odds ratio 1.14, 95% confidence interval 0.70-1.85; P = 0.59).

CONCLUSIONS

Microscopic BNI+ in prostate cancer is not an independent risk factor for biochemical progression and should be regarded as a factor that worsens the prognosis of the underlying tumour stage. A longer follow-up is necessary to confirm these findings.