Female gender is associated with higher risk of disease recurrence in patients with primary T1 high-grade urothelial carcinoma of the bladder

Purpose: An increasing body of evidence suggests gender differences in the presentation and prognosis of bladder cancer. We aimed to assess the impact of gender on outcomes in patients with primary T1 high-grade (HG) urothelial carcinoma of the bladder (UCB). Methods: We retrospectively analysed the data from 916 patients with primary T1HG UCB from 7 tertiary care centres. Patients were treated with transurethral resection of the bladder with or without intravesical instillation therapy (IVT). Univariable and multivariable Cox regression analyses assessed the effect of gender on outcomes. Results: Within a median follow-up of 42.8 months, 365 (39.8 %) patients experienced disease recurrence, 104 (11.4 %) progression, 59 (6.4 %) cancer-specific mortality and 190 (20.7 %) mortality of any cause. Overall, 634 (69.2 %) patients received IVT of which 234 (25.5 %) received BCG therapy. Female gender (n = 190, 20.7 %) was associated with higher risk of disease recurrence (HR:1.359;1.071-1.724, p = 0.012) in all patients and in a subgroup of patients treated with BCG therapy (HR:1.717;1.101-2.677, p = 0.017). There was no difference between genders with regard to disease progression, cancer-specific mortality and any-cause mortality. In multivariable analyses that adjusted for the effects of concomitant carcinoma in situ (CIS), tumour size, number of tumours, and IVT, gender remained an independent predictor for disease recurrence (p = 0.026) when analysed in all patients, but not in the subgroup of BCG treated patients (p = 0.093). Conclusions: In patients with T1HG UCB, female gender is associated with higher risk of disease recurrence, but not with disease progression. This gender disparity may be due to differences in care and/or biology of UCB.