Platinum-based chemotherapy appears active in the treatment of metastatic triple-negative breast cancers, particularly among patients with a BRCA1/2 mutation. These findings were reported in the Journal of Clinical Oncology.
Breast cancers that are not stimulated to grow from exposure to estrogen or progesterone and are HER2 (human epidermal growth factor receptor)-negative are called triple-negative breast cancers. Triple-negative breast cancers tend to be more aggressive than other breast cancers and have fewer treatment options.
Platinum-based chemotherapy is a potential treatment option for some patients with triple-negative breast cancer. Researchers are currently interested in finding ways to identify which patients are more likely to benefit from platinum drugs.
Researchers recently conducted a study to evaluate the platinum chemotherapy drugs Platinol® (cisplatin) and carboplatin in patients with metastatic triple-negative breast cancer. Their goals were to measure the effectiveness of platinum therapy as well as find ways to determine which patients were likely to benefit.
The study included 86 patients with metastatic triple-negative breast cancer who were treated with platinum chemotherapy as first- or second-line treatment. They received either Platinol (43 patients) or carboplatin (43 patients).
Among all patients, 25.6% responded to treatment. The response rate for Platinol was higher at 23.6% than carboplatin at 18.7%.
The patients’ BRCA mutation status appeared to influence their response to platinum chemotherapy. Of the 11 individuals with BRCA1/2 mutations, 54.5% responded to treatment. Of the 66 patients without a BRCA mutation, 32 patients with something known as genomic instability, or gene mutations similar to BRCA, appeared more likely to respond to treatment.
The researchers concluded that platinum chemotherapy agents were active in the treatment of metastatic triple-negative breast cancer. Patients with BRCA mutations were most likely to benefit, and patients without BRCA mutations with genomic instability similar to BRCA could also benefit. These findings call for more study into platinum-based chemotherapy for these patients.
Reference: Isakoff SJ, Mayer EL, He L, et al. A Multicenter Phase II Clinical Trial of Platinum Monotherapy With Biomarker Assessment in Metastatic Triple-Negative Breast Cancer. Journal of Clinical Oncology. 10.1200/JCO.2014.57.6660.