Clinical Outcomes of Micropapillary Urothelial Carcinoma of the Bladder Treated With Radical Cystectomy.

Background/aim: This study examined the treatment outcomes of radical cystectomy (RC) for micropapillary subtype (MPS) bladder cancer treated at our hospital.

Patients and methods: Histopathological findings of RC specimens collected from 2003 to 2020 were evaluated. Recurrence-free survival (RFS) and overall survival (OS) after RC, as well as the efficacy of chemotherapy in cases of recurrence, were retrospectively assessed.

Results: Of 202 patients who underwent RC, seven (3.4%) had MPS bladder cancer. All seven patients underwent immediate RC without neoadjuvant chemotherapy. The median patient age was 58 years (range=52-71 years), and all patients were male. After RC, median RFS was 14 months (range=6-115 months), and median OS was 31 months (range=18-115 months). The clinical tumor stage was cT1 or lower in two patients (28.5%), cT2 in two patients (28.5%), and cT3 or higher in three patients (42.8%). No preoperative lymph node metastasis was observed. The pathological tumor stage was pT1 or lower in one patient (14.2%), pT2 in one patient (14.2%), and pT3 or higher in five patients (71.4%). The pathological lymph node stage was observed in five patients (71.4%). Although six of seven patients (85.7%) received adjuvant chemotherapy, all patients experienced relapse. The objective response rates of primary and secondary chemotherapy at relapse were both 33%. One patient received immune checkpoint inhibitor therapy and maintained stable disease for 12 months.

Conclusion: The recurrence rate after RC for MPS bladder cancer was high, and prognosis was poor.