Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratio help identify patients with lung cancer, but do not differentiate between lung cancer subtypes

AIM: To assess the diagnostic value of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in lung cancer (LC). We compared the ratios between healthy participants and all LC patients, as well patients with different pathohistological LC subtypes. METHODS: We retrieved the data on neutrophil, lymphocyte, and platelet levels in 449 patients with different pathohistological LC subtypes (non-small cell LC, small-cell LC, atypical or metastatic LC, neuroendocrine, and sarcomatoid carcinoma) and 47 healthy controls. NLR and PLR were calculated by dividing the absolute number of neutrophils or platelets with the absolute number of lymphocytes. RESULTS: There were significant differences in both NLR and PLR (P < 0.001) between all LC patients and the control group, but there were no differences between patients with different LC subtypes. Reciever operating characteristics analysis for NLR showed the optimal cut-off value of 2.71, with a sensitivity of 77.05% and specificity of 87.23%. The optimal cut-off value for PLR was 182.31, with a sensitivity of 51.09% and specificity of 91.49%. CONCLUSION: The results showed that the NLR and PLR may have added value in the early diagnosis of LC, but further research is needed to confirm these results.