Clinical outcome of patients with T1 micropapillary urothelial carcinoma of the bladder

Purpose We report cancer specific outcomes of micropapillary nonmuscle invasive bladder cancer. Materials and Methods We retrospectively reviewed the records of 36 cases restaged within 3 months of the initial diagnosis of micropapillary nonmuscle invasive bladder cancer. Early radical cystectomy within a 3-month landmark after restaging transurethral bladder tumor resection or conservative treatment with intravesical bacillus Calmette-Guérin, surveillance or deferred radical cystectomy was offered according to surgeon and patient preference. The cumulative incidence of cancer specific mortality and metastasis was estimated using the Kaplan-Meier method. Differences in the cumulative incidence of cancer specific mortality and metastasis between the groups were tested using the log rank test. Results Median patient age was 68 years (IQR 63-77). The male-to-female ratio was 3:1. At restaging all patients had cT1 disease or less. Early radical cystectomy was performed in 15 patients (42%) while 21 (58%) underwent conservative treatment. Median followup after landmark in cancer specific survivors was 3.1 years (IQR 1.1-5.9). The 5-year cumulative incidence of cancer specific mortality was 17% in the early radical cystectomy group and 25% in the conservative management group for an absolute difference of 7% (95% CI -26-41, p = 0.8). The 5-year cumulative incidence of metastasis was 21% and 34%, respectively, with an absolute difference of 13% (95% CI -23-49, p = 0.9). The extent of the micropapillary component was not significantly associated with cancer specific mortality (p = 0.4) or metastasis (p = 0.9). Conclusions Using proper selection criteria, including patient and pathological factors, certain patients in whom cT1 micropapillary urothelial carcinoma was managed conservatively did not have significantly worse outcomes than patients treated with early radical cystectomy.