Neutrophil-lymphocyte ratio and prediction of pathological complete response to neoadjuvant treatment in breast cancer.

Abstract

e12627 Background: Pathological complete response (pCR) after neoadjuvant therapy in breast cancer is an important prognostic indicator for improved disease free survival. High tumour grade, low ER-status, HER2-positivity predict higher likelihood of a pCR however better predictive biomarkers are needed. The role of the immune system and specifically the presence of tumour infiltrating lymphocytes in increasing response to chemotherapy has been extensively studied across cancer subtypes2. We sought to determine if neutrophil-to-lymphocyte ratio (NLR) as a marker of immune inflammatory response could be informative in predicting likelihood of pCR. Methods: We identified a cohort of patients who had received neoadjuvant chemotherapy between 2012 to 2018. We extracted clinical, pathological and laboratory data for each case. A pretreatment peripheral blood test was used to calculate a neutrophil-to-lymphocyte ratio. We used R-studio to analyse our data. The primary objective was to determine if there was an association between NLR and pCR. Statistical analysis was performed to assess whether NLR ratio correlated with pCR. Results: We identified 107 patients who had received NAC for early stage breast cancer during our study period. The mean NLR in the cohort was 2.95 (range 0.76-11.9). 35 (32.7%) patients achieved a pCR. There was no statistically significant different in NLR in those who achieved pCR (n=35) and those who did not (n=72) (p value= 0.75). Patients with triple negative breast cancer (TNBC) had a higher rate of pCR (45.1%), compared to HER2-positive (42.1%) and ER-positive HER2-negative (25.4%). The NLR was not significant in predicting pCR within the separate histological cohorts. Conclusions: NLR did not predict for pathological complete response in our cohort. Further studies into the predictive value of NLR in this setting with larger cohorts are needed. Investigation into the dynamic changes of NLR both pre, post during treatment may provide further insights as may larger cohorts for analysis in each histological subtype.