The neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios predict efficacy of platinum-based chemotherapy in patients with metastatic triple negative breast cancer

Platinum salts are active against metastatic triple negative breast cancer (mTNBC), and biomarkers to predict their effectiveness are urgently needed. In recent years, the neutrophil-to-lymphocyte ratio (NLR) and the platelet-to-lymphocyte ratio (PLR) have emerged as prognostic biomarkers in many malignancies, but their predictive role in platinum-treated mTNBC patients remains unexplored. We performed a retrospective, single centre study to evaluate the association between baseline NLR or PLR and progression free survival (PFS) of mTNBC patients treated with platinum-based chemotherapy. As a control population, we analysed data from patients with hormone receptor-positive HER2-negative (HR+ HER2-) metastatic breast cancer. Among 57 mTNBC patients treated with the carboplatin-paclitaxel or carboplatin-gemcitabine combination, high NLR and PLR were associated with significantly lower PFS at both univariate and multivariable analysis. Conversely, we did not find a significant association between NLR or PLR and the PFS of 148 patients in the control population. Our findings suggest that the NLR and PLR are predictive of benefit from platinum-containing chemotherapy specifically in mTNBC patients. If validated in larger prospective studies, these easy-to-measure parameters could be combined with emerging predictive biomarkers, such as BRCA 1/2 mutations, to improve the selection of mTNBC patients more likely to benefit from platinum-based chemotherapy.