Phase II evaluation of carboplatin and VP-16 for patients with metastatic breast cancer and only one prior chemotherapy regimen.

Abstract

BACKGROUND. New salvage chemotherapy is needed for metastatic breast cancer. Cisplatin and VP-16 have activity but considerable toxicity. This study determines the response rate, response duration, and toxicity of a combination chemotherapy regimen of the better-tolerated carboplatin plus VP-16 in a group of patients with metastatic breast cancer and only one prior exposure to cytotoxic chemotherapy. Twenty-three patients received an average of 2.8 courses of treatment before a lack of response or progression of disease was noticed. Four patients had evidence of rapidly progressive disease or early death and received only one course. No complete responses occurred, but three patients (13%) experienced partial responses. Mean response duration was 5 months. Metastatic disease which responded included lung, lymph node, and chest wall sites. Toxicity was mainly myelosuppression with 57% of patients having grade 3-4 neutropenia or thrombocytopenia. Two patients (8%) had significant infection with neutropenia requiring hospitalization but no toxic deaths occurred. Carboplatin and VP-16 at this dose and schedule was a reasonably well-tolerated regimen with only modest activity in metastatic breast cancer as second-line cytotoxic chemotherapy.