High neutrophil‐to‐lymphocyte ratio as an early sign of cardiotoxicity in breast cancer patients treated with anthracycline

BACKGROUND: Cardiotoxicity, defined mainly as left ventricle (LV) dysfunction, is a significant side effect of anthracyclines (ANT) therapy. The need for an early simple marker to identify patients at risk is crucial. A high neutrophil‐to‐lymphocyte ratio (NLR) has been associated with poor prognosis in cancer patients; however, its role as a predictor for cardiotoxicity development is unknown. OBJECTIVE: Evaluating whether elevated NLR, during ANT exposure, plays a predictive role in the development of cardiotoxicity as defined by LV global longitudinal strain (LV GLS) relative reduction (≥10%). METHODS AND RESULTS: Data were prospectively collected as part of the Israel Cardio‐Oncology Registry. A total of 74 female patients with breast cancer, scheduled for ANT therapy were included. NLR levels were assessed at baseline (T1) and during ANT therapy (T2). All patients underwent serial echocardiography at baseline (T1) and after the completion of ANT therapy (T3). NLR ≥ 2.58 at T2 was found to be the optimal predictive cutoff for LV GLS deterioration. A relative LV GLS reduction ≥10% was significantly more common among patients with high NLR (50% vs. 20%, p = .009). NLR ≥ 2.58 at T2 increases the risk for LV GLS reduction by fourfold (odds ratio [OR]: 4.63, 95% confidence interval [CI]: 1.29–16.5, p = .02), with each increase of 1‐point NLR adding an additional 15% risk (OR: 1.15, 95% CI: 1.01–1.32, p = .046). CONCLUSIONS: Our study provides novel data that high NLR levels, during ANT exposure, have an independent association with the development of LV dysfunction. Routine surveillance of NLR may be an effective means of risk‐stratifying.