BACKGROUND AND AIM: The neutrophil/lymphocyte ratio (NLR) has been demonstrated to be a prognostic marker in various cancers, including non-small cell lung cancer (NSCLC). Nevertheless, very little is known about this ratio in the specific NSCLC population that includes a targetable epidermal growth factor receptor (EGFR) mutation.

METHODS: Histologically or cytologically confirmed stage IIIB or IV NSCLC cases with a targetable EGFR mutation between 2014 and 2018 were retrospectively evaluated. The optimal cut-off value for NLR for prognostic purposes was determined by Receiver Operating Characteristic (ROC) analysis. The patients were divided into two groups according to the determined cut-off value, and the groups were compared in terms of variables, and the effect on overall survival was evaluated. Univariate cox regression analysis included age, gender, the extent of the primary tumor (T), involvement of regional lymph nodes (N), Tumor, Node, and Metastasis (TNM), and cancer treatment, in addition to NLR.

RESULTS: The study included 62 patients. In the ROC analysis, Area Under the Curve (AUC): 0.643 (95% Confidence Interval (CI): 0.504−0.783), and the cut-off for NLR was determined as 2.57 considering the highest “Youden’s index”. Accordingly, the specificity was found to be 51.85%, and sensitivity was 74.29%. Survival was 23 (15.824−30.176) months in the NLR>2.57 group, while it was 38 (29.665−46.335) months in the NLR equal to or lower than 2.57 (p=0.218). No statistically significant difference was found between the NLR rate and overall survival (OS).

CONCLUSIONS: Although no statistical significance was reached, the high NLR ratio was possibly found to be associated with poor prognosis in cases with EGFR mutant lung cancer, mostly composed of stage 4 cancer.