Prognostic implications of prostatic urethral involvement in non-muscle-invasive bladder cancer

Non-muscle-invasive bladder cancer involving the prostatic urethra is associated with pathologic upstaging and shorter survival. We investigated the survival impact of prostatic urethral involvement in non-muscle-invasive patients who are not upstaged at cystectomy.

From 2000 to 2016, 177 male patients underwent cystectomy for high-risk non-muscle-invasive bladder cancer and remained pT1, pTis, or pTa, and N0 on final pathology; 63 (35.6%) patients had prostatic urethral involvement and 114 (64.4%) did not. Prostatic involvement was non-invasive (Ta or Tis) in 56 (88.9%) patients and superficially invasive (T1) in 7 (11.1%) patients. No patient had stromal invasion. Log-rank and Cox regression analyses were used to evaluate survival.

Compared to patients without prostatic urethral involvement, patients with involvement were more likely to have received intravesical therapy (84.6% vs. 64.4%, p < 0.01), have multifocal tumor (90.8% vs. 51.7%, p < 0.01), and have positive urethral margins (7.7% vs. 0%, p < 0.01) and ureteral margins (18.5% vs. 5.1%, p < 0.01). Log-rank comparison showed inferior recurrence-free, cancer-specific, and overall survival in patients with prostatic involvement (p = 0.01, p = 0.03, p < 0.01). Patients with prostatic urethral involvement were more likely to experience recurrence in the urinary tract (p < 0.01). On Cox regression, prostatic urethral involvement was an independent predictor of overall mortality (HR = 2.08, p < 0.01).

Prostatic urethral involvement is associated with inferior survival in patients who undergo cystectomy for non-muscle-invasive bladder cancer and remain pT1, pTis, or pTa on final pathology. Prostatic urethral involvement is thus an adverse pathologic feature independent of its association with upstaging.