Purpose: Collecting duct carcinoma of the kidney is a rare and aggressive neoplasm of the distal collecting tubules for which there is no established treatment. Since the histology of collecting duct carcinoma is similar to that of urothelial carcinoma, the standard chemotherapy regimen defined by a gemcitabine and platinum salts combination was prospectively investigated in patients with metastatic collecting duct carcinoma.
Materials and methods: A total of 23 patients with metastatic collecting duct carcinoma with no prior systemic chemotherapy were treated with 1,250 mg/m(2) gemcitabine on days 1 and 8 plus 70 mg/m(2) cisplatin or carboplatin (AUC 5) in patients with renal insufficiency on day 1. The drugs were repeated every 21 days for 6 cycles according to toxicity and efficacy. The objective response rate was the primary end point.
Results: There were 1 complete and 5 partial responses for an objective response rate of 26% (95% CI 8 to 44). Median progression-free and overall survival was 7.1 (95% CI 3 to 11.3) and 10.5 months (95% CI 3.8 to 17.1), respectively. Toxicity was mainly hematological with grade 3-4 neutropenia and thrombocytopenia in 52% and 43% of patients, respectively. The severity of granulocytopenia and the number of metastatic sites were associated with overall survival on univariate and multivariate analyses.
Conclusions: To our knowledge this is the first prospective, multicenter, phase II study showing that the platinum salts combination is an active and safe regimen as first line treatment in patients with metastatic collecting duct carcinoma. This platinum based chemotherapy should be considered the standard regimen in these patients.