Peer Review #1 of "Neutrophil–lymphocyte ratio is prognostic in early stage resected small-cell lung cancer (v0.2)"

Abstract

Background For selected early-stage small cell lung cancer (SCLC), curative intent surgery is often performed. Previous studies, predominantly from East Asia, reported that high neutrophil to lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) correlate with poor prognosis in several types of tumors including SCLC. Our aim was to investigate the prognostic value of NLR and PLR in Caucasian patients with resected SCLC, as potential tool to select patients for multimodal treatment including surgery. Methods Consecutive patients evaluated at three centers between 2000 and 2013 with histologically confirmed and surgically resected SCLC were retrospectively analyzed. NLR and PLR at diagnosis was used to categorize patients into "high" and "low" groups based on ROC analysis. Univariate and multivariate analyses were used to evaluate the impact of clinical and pathological characteristics on outcome. Results There were a total of 189 patients with a median age of 58 years, and the majority had stage I or II disease. We found a significant correlation between NLR and tumor stage (p=0.007) and age (p=0.038). Low NLR (LNLR) was associated with significantly longer overall survival (OS), while PLR had no prognostic impact. There were significant associations between NLR and PLR but not with gender, vascular involvement, tumor necrosis, peritumoral inflammation, or tumor grade. Conclusion Pre-operative LNLR may be a favorable prognostic factor in stage I-II SCLCs. PLR is not prognostic in this population. LNLR is easy to assess and can be integrated into routine clinical practice. Further prospective studies are needed to confirm these observations.