Purpose: Micropapillary bladder carcinoma is a rare variant of UC. Due to paucity of data regarding treatment outcomes, patients with nonmuscle invasive micropapillary UC often receive intravesical therapy in an attempt at bladder preservation.
Materials and methods: We reviewed the records of all patients evaluated at our institution who had micropapillary UC of the bladder. Of these, 44 had nonmuscle invasive disease at presentation and form the basis of this report.
Results: Mean patient age was 64.3 years (range 45 to 81) with a male-to-female ratio of 13:1. Stage distribution at presentation was 5 Ta (11%), 4 CIS (9%) and 35 T1 (80%). Median CSS was 81 months. Kaplan-Meier estimates of 5 and 10-year CSS rates were 64% and 26%, respectively. Intravesical BCG therapy was attempted in 27 patients (61%). Of these 27 patients, 67% (18 of 27) had progression (cT2 or greater), including 22% in whom metastatic disease developed. Only 19% of patients (5 of 27, all T1) remain disease-free with an intact bladder at a median followup of 30 months. A total of 30 patients (68%) underwent cystectomy. Among patients who underwent cystectomy after progression (18), median CSS was 61.7 months with no patient surviving 10 years, whereas among those undergoing cystectomy as initial therapy (12), median survival was not reached and the 10-year CSS rate was 72%.
Conclusions: Intravesical BCG therapy appears to be ineffective against micropapillary UC. Our results suggest that the optimal treatment strategy for nonmuscle invasive micropapillary UC is radical cystectomy performed before progression.