Collecting duct carcinoma: A single-institution retrospective study

Abstract

Purpose: Collecting duct carcinoma is a rare pathologic entity with a paucity of clinical data in the literature. We aim to evaluate our institutional experience with the management of this disease.

Materials and methods: All renal tumors in the Mayo Clinic Nephrectomy Registry were re-reviewed retrospectively by an expert urologic pathologist. Cases of collecting duct carcinoma were identified. Descriptive statistics were used to characterize these cases. Overall survival and metastases-free survival were estimated using Kaplan-Meier methodology.

Results: Between 1970 and 2018, a total of 21 cases were identified with an incidence of 0.2%. Cases were seen predominantly in men (N = 17, 81%) with a median age at diagnosis of 57 years old. At the time of nephrectomy, high grade disease (grade 3 or 4) was noted in the majority of patients (90%). The median times to local recurrence and distant metastases were 5.6 and 5.1 months, respectively. Median overall survival occurred at 1.5 years. Median distant metastases-free survival among M0 patients occurred at 0.5 years. Four patients with localized disease and small tumor size who underwent nephrectomy lived longer than 10 years. No systemic therapies achieved a durable response in the metastatic setting.

Conclusion: The Mayo Clinic nephrectomy registry contains 21 patients with collecting duct carcinoma over nearly 50 years. Early local recurrence and distant metastases were seen after nephrectomy. However, M0 patients with a small tumor may have long-term benefits from nephrectomy. Neither chemotherapy nor targeted therapy resulted in a durable response in the metastatic setting.

Keywords: Collecting duct carcinoma; Non-clear cell renal cell carcinoma.