The impact of inflammatory markers on prognosis of stage II colon cancers depends on tumour sidedness

Backgrounds: Accumulating evidence has reported a high correlation between inflammatory markers and oncological outcomes in colorectal cancer. In the present study, we aimed to assess the prognostic values of five inflammatory markers in stage II colon cancer patients with different tumour locations. Methods: The consecutive stage II colon adenocarcinoma patients undergoing curative resection were analysed retrospectively. ROC curves and the area under the curve (AUCs) via bootstrap method were used to analyse the prognostic impact of various inflammatory markers, including neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), systemic immune-inflammation index (SII) and prognostic nutrition index (PNI). Results: A total of 768 patients were enrolled for analysis. In univariate analysis, right-sided colon cancer (RCC) patients have significantly higher mean levels of all inflammatory markers than left-sided colon cancer (LCC) patients. In multivariate analyses, high NLR in LCC (P = 0.025) and low PNI in both RCC (P = 0.049) and LCC (P = 0.027) were significantly associated with a worse OS while none of the inflammatory markers was found to have a significant impact on DFS or CSS. Conclusions: The profiles and prognostic impact of inflammatory markers are significantly different between stage II RCC and LCC patients. Researchers should take sidedness into consideration when addressing survival analysis of inflammatory markers.