Prognostic significance of the lymphocyte-to-neutrophil ratio in percutaneous fine-needle aspiration biopsy specimens of advanced nonsmall cell lung carcinoma

Abstract

BACKGROUND. The prognostic significance of tumor-infiltrating lymphocytes (TILs) in surgically resected carcinomas was reported. To apply this to inoperable non-small cell lung carcinomas (NSCLC) of Stage IIIB-IV, the authors estimated the occurrence of TILs using percutaneous fine-needle aspiration biopsy specimens, and tested the validity of this method. METHODS. The authors defined the L-N index as [LS/(LS + NS) - L B/(LB + NB)], in which LS and N S denoted lymphocyte and neutrophil counts in the aspiration smear, and LB and NB denoted lymphocyte and neutrophil counts in the peripheral blood specimen. The cutoff value was set at twice the standard deviation of the L-N index of 41 smears contaminated with abundant blood. Retrospectively, the authors compared the survival rate of the group with a high L-N index (lymphocyte-dominant group) (n = 12) with the survival rate of the group with a low L-N index (lymphocyte-nondominant group) (n = 60). Then, they performed a prospective study and compared the survival rates of these 2 groups (n = 21 and n = 54). The Cox proportional hazards model was used to determine the effect of the L-N index as a continuous variable and other prognostic factors. The correlation (r) between the L-N index-based grouping (L-N grouping) and the histologie grade of TILs was studied among resected lung tumor specimens (n = 164). RESULTS. In the retrospective and prospective studies, the survival rate was significantly higher in the lymphocyte-dominant group than in the lymphocyte-nondominant group (P = 0.0019 and P = 0.0001). Using multivariate analysis, the L-N index was an independent prognostic factor. A significant correlation was noted between L-N grouping and histologic grade of TILs (r = 0.476). CONCLUSIONS. The L-N index of aspiration smears was found to be an independent prognostic factor for patients with advanced-stage NSCLC. L-N grouping was correlated with the histologic assessment of TILs. © 2005 American Cancer Society.