Carboplatin and Gemcitabine Combination in Metastatic Triple-Negative Anthracycline- and Taxane-Pretreated Breast Cancer Patients: A Phase II Study

Triple-negative breast cancer (TNBC) is characterized by lack of hormone receptors and HER-2 and shares many features with BRCA1-associated cancer. Preclinical data indicate cisplatin sensitivity, suggesting that these tumors may have defects in the BRCA1 pathway. The carboplatin and gemcitabine (CG) combination is active in unselected anthracycline/taxane pretreated metastatic breast cancer patients, so we carried out a phase II study to evaluate the activity of the CG combination in pretreated metastatic TNBC patients. From 10/2004 to 3/2009 we enrolled 31 patients. Median age was 57 years and 29 patients out of 31 had visceral involvement. The overall response rate (ORR) was 32% (1 complete response /9 partial responses), in addition 5 patients obtained stable disease for >= 12 weeks. After a median follow-up of 34 months, all patients progressed with a median time to progression of 5.5 months and median overall survival of 11 months. Dose reductions, delays and omissions occurred in 75 (60%), 36 (29%) and 22 (18%) cycles. Grade 3/4 neutropenia occurred in 17 and febrile neutropenia in 4 patients. Ten patients had Grade 3/4 thrombocytopenia. Non hematological toxicities were manageable. The CG combination is a reasonable option for the treatment of metastatic pretreated TNBC patients.