Sex-related differences in urothelial cell carcinoma of the bladder in Germany

Background: Urothelial cell carcinoma (UCC), also called transitional cell cancer, occurs significantly more often in males than in females. Essential for the prognosis of recovery is depth of infiltration (muscle-invasive or non-muscle invasive) and tumor-differentiation at initial diagnosis. The current study aimed to explore sex-related differences after initial diagnosis of UCC in Germany. Methods: We identified patients who underwent transurethral resection of the bladder tumor (TUR-BT). Data were retrospectively analyzed, including TNM classification, histopathological grading, risk group according to the European Association of Urology (EAU), use of photodynamic diagnosis (PDD), and early intravesical chemotherapy (IVC). Results: A total of 539 male and 190 female patients with UCC underwent TUR-BT. Approximately 75% were non-muscle invasive bladder cancer (NMIBC). Females evidenced significantly higher rates of muscle-invasive bladder cancer (MIBC; P=0.04). Carcinoma in situ (CIS) was significantly more common among males (P=0.01). Recurrence and progression rates showed no significant sex differences-only in the small subgroup of EAU low-risk NMIBC females, we found a significantly higher progression rate (P=0.03). In a Cox proportional hazards model, we found for MIBC, an HR for progression of 6.5 (95% CI, 1.29-33.2; P=0.02) after a median follow-up of 56 months. Use of PDD or IVC showed no significant differences in recurrence and progression between females and males. Conclusion: Females were significantly more likely to suffer from MIBC at the time of first diagnosis. In NMIBC, males showed a significantly higher prevalence of CIS and EAU low-risk NMIBC females showed significantly higher rates of progression. Sex was not associated with recurrence rates in NMIBC. PDD and IVC were equally effective in both sexes. Based on the collected data we suggest to further investigate possible sex differences in UCC with therapeutical impact. Additional prospective multicenter studies are needed to evaluate both sex-related long-term disease courses and effectiveness of therapies.