Sex-Related Differences Include Stage, Histology, and Survival in Urethral Cancer Patients

To test the effect of sex on histologic subtype, stage at presentation, treatment, and cancer-specific mortality (CSM) in urethral cancer.

We identified urethral cancer patients within the Surveillance, Epidemiology, and End Results (SEER) registry (2004-2016). After matching for tumor and patient characteristics, cumulative incidence plots and multivariable competing risks regression models, adjusted for other-cause mortality, tested CSM according to sex.

Of 1645 eligible urethral cancer patients, 1073 (65%) were male. Urothelial histologic subtype was most frequent in male (59%) but not female (27%) subjects. Adenocarcinoma, squamous cell carcinoma, and other histologies were more frequent in female patients. Most male subjects harbored T1N0M0 (32%) stage disease, whereas most female subjects harbored T3-4N0M0 (29%) stage disease. In urothelial and adenocarcinoma histologic subtypes, African American female subjects were most prevalent (31 and 78%) versus whites (16 and 52%) versus Hispanics (27 and 74%). In T1N0M0 stage, single-mode surgical treatment was more frequent in male than female patients (respectively, 73% vs 59%). In T3-4 and/or N1-2 stage disease, multimodal therapy was more frequent in female than male (42% vs 37%) patients. In nonmetastatic urethral cancer (T1-4N0-2M0), after propensity score matching for stage, race, treatment, and age, cumulative incidence plots showed 5-year CSM of 36% and 25% in female and male patients, respectively, and after further multivariable adjustment resulted in 1.3-fold higher CSM in female as opposed to male patients (P = .07).

Female patients with urethral cancer present with higher disease stage. Despite higher rates of multimodal therapy, and despite matching for stage disadvantage, female subjects with urethral cancer exhibited higher CSM.