Cisplatin-gemcitabine therapy in metastatic breast cancer: Improved outcome in triple negative breast cancer patients compared to non-triple negative patients.

Triple negative or basal-like breast cancers lack expression of estrogen, progesterone and HER2neu receptors. There are no specific treatment guidelines for this group of patients, however, it has been postulated that their phenotypic and molecular similarity to BRCA-1 related cancers would confer sensitivity to certain cytotoxic agents like cisplatin (CDDP). The aim of the study was to retrospectively examine the clinical outcome at our institution of patients with metastatic breast cancer treated with CDDP and gemcitabine combination chemotherapy who had triple negative breast cancer compared to non-triple negative breast cancer. Thirty-six patients with metastatic breast cancer were treated with CDDP and gemcitabine combination chemotherapy, 17 of whom were triple negative (47%) and 19 were non-triple negative (53%). The median progression free survival for triple negative and non-triple negative metastatic breast cancer patients were 5.3 months and 1.7 months respectively (p = 0.058). By multivariate Cox proportional hazard model after adjusting for age, race and menopausal status the risk of progression was reduced by 47% for triple negative compared to non-triple negative metastatic breast cancer patients (HR = 0.53, p = 0.071).