Assessing the clinical utility of pre-operative neutrophil–lymphocyte ratio as a predictor of clinicopathological parameters in patients being treated for primary breast cancer

Background: There is a paucity of data supporting the role of neutrophil–lymphocyte ratios (NLR) to determine clinicopathological parameters in patients being treated for primary breast cancer. Aims: To evaluate the association between pre-operative NLR and clinicopathological parameters in patients diagnosed with breast cancer. Methods: A retrospective cohort study was performed. This included consecutive patients indicated to undergo surgery for primary breast cancer at University Hospital Limerick between January 2010 and June 2017. NLR was expressed as a continuous variable. Univariable and multivariable linear regression analyses were used to determine the correlation between NLR and clinicopathological data. Data analytics was performed using SPSS v29.0. Results: 673 patients met the inclusion criteria. Overall, the median preoperative NLR is 2.63 (standard deviation: 1.42). At univariable analysis, patient age (beta coefficient: 0.009, 95% confidence interval (CI) 0.001–0.017, P = 0.027), tumour size (beta coefficient: 0.013, 95% CI 0.005–0.021, P = 0.001), and human epidermal growth factor receptor-2 status (beta coefficient: − 0.370, 95% CI − 0.676–0.065, P = 0.017) were all predicted using NLR. However, at multivariable analysis, tumour size was the sole parameter predictable by NLR (beta coefficient: 0.011, 95% CI 0.002–0.019, P = 0.013). Conclusions: This study demonstrates that pre-operative NLR may serve as an independent predictor of tumour size in patients being treated with primary breast cancer. Ratification of these preliminary findings is warranted before robustly adopted into clinical practice.