Pretreatment neutrophil-to-lymphocyte ratio is correlated with response to neoadjuvant chemotherapy as an independent prognostic indicator in breast cancer patients: a retrospective study

Background: A high neutrophil-to-lymphocyte ratio (NLR) may be related to increased mortality in patients with lung, colorectal, stomach, liver, and pancreatic cancer. To date, the utility of NLR to predict the response to neoadjuvant chemotherapy (NAC) has not been studied. The aim of our study was to determine whether the NLR is a predictor of response to NAC and to investigate the prognostic impact of the NLR on relapse-free survival (RFS) and breast cancer-specific survival (BCSS) in patients with breast cancer who received NAC. Methods: We retrospectively studied patients who received NAC and subsequent surgical therapy for stage II-III invasive breast carcinoma at Sun Yat-sen Memorial Hospital between 2001 and 2010. The correlation of NLR with the pathological complete response (pCR) rate of invasive breast cancer to NAC was analyzed. Survival analysis was used to evaluate the predictive value of NLR. Results: A total of 215 patients were eligible for analysis. The pCR rate in patients with lower pretreatment NLR (NLR < 2.06) was higher than those with higher NLR (NLR >= 2.06) (24.5 % vs. 14.3 %, p < 0.05). Those patients with higher pretreatment NLR (NLR >= 2.1) had more advanced stages of cancer and higher disease-specific mortality. Through a multivariate analysis including all known predictive clinicopathologic factors, NLR >= 2.1 was a significant independent parameter affecting RFS (HR: 1.57, 95 % CI: 1.05-3.57, p < 0.05) and BCSS (HR: 2.21, 95 % CI: 1.01-4.39, p < 0.05). Patients with higher NLR (NLR >= 2.1) before treatment showed significantly lower relapse-free survival rate and breast cancer-specific survival rate than those with lower NLR (NLR < 2.1) (log-rank p = 0.0242 and 0.186, respectively). Conclusions: Pretreatment NLR < 2.06 is associated with pCR rate, suggesting that NLR may be an important factor predicting the response to NAC in breast cancer patients. NLR is an independent predictor of RFS and BCSS in breast cancer patients with NLR >= 2.1 who receive NAC. We suggest prospective studies to evaluate NLR as a simple prognostic test for breast cancer.