Pathological response to neoadjuvant chemotherapy for muscle-invasive micropapillary bladder cancer.

Abstract

To describe the pathological outcomes of patients with muscle-invasive micropapillary bladder cancer who have undergone neoadjuvant chemotherapy. A total of 82 patients with muscle-invasive micropapillary bladder cancer were treated between 1997 and 2010. After excluding those with metastatic disease, micropapillary histology only at radical cystectomy (RC), and chemo-radiation as primary treatment, 44 patients remained. All patients had ≥cT2 disease before chemotherapy/surgery. The median follow-up after RC was 28 months. Neoadjuvant chemotherapy was initiated in 29 (66%) patients and all patients underwent RC (93%) or partial cystectomy (7%). Micropapillary histology was diagnosed at first transurethral resection in 37 (84%) patients. Final RC pathology revealed pT0 in 15 (34%) patients and positive lymph nodes in 13 (31%) patients. Down-staging to pT0 occurred in 13 (45%) of those who received neoadjuvant chemotherapy compared with two (13%) of those who did not (P = 0.049). Patients with pT0 disease with micropapillary histology had higher overall survival rates (25 vs. 92%) and lower rates of bladder cancer recurrence (21 vs. 79%) at the 24-month follow-up. Almost half of the patients responded completely to neoadjuvant chemotherapy with a pT0 rate of 45%; therefore, patients with the micropapillary variant of urothelial carcinoma should not be excluded from consideration for neoadjuvant chemotherapy.