Abstract: Objective To explore the application value of different inflammatory markers in the diagnosis of early colorectal cancer and precancerous lesions. Methods We collected the general data, laboratory examination results, colonoscopy results and other clinical medical records of patients with early colorectal cancer and precancerous lesions in the digestive endoscopy center of our unit from February 2008 to January 2019, and analyzed the correlation between inflammatory markers and clinicopathological characteristics of early colorectal cancer and precancerous lesions. Results The univariate analysis showed that smoking history(P =0.006), lesion location(P =0.000), lesion size(P =0.000), lesion number(P =0.004), lesion treatment method(P =0.000), neutrophil count(P =0.000), NLR(P =0.000), SII(P =0.001)are related to the pathological properties of early colorectal cancer and colorectal precancerous lesions. Multivariate Logistic regression analysis showed that history of hyperlipidemia(P =0.009), lesion location(P =0.000), lesion size(P =0.000), lesion number(P =0.024), SII (P =0.004)are independent predictors of the pathological properties of the two groups of patients, and the area under the ROC curve of SII to distinguish the two groups of patients is 0.643 (95% CI: 0.560－0.725; P=0.001). When the SII is 500.27, its sensitivity for diagnosing early colorectal cancer is 54.9%, and its specificity is 70.7%, but the consistency between the diagnostic results and pathological is poor (Kappa < 0.40). Conclusion The use of SII in the screening of early colorectal cancer and precancerous lesions may be helpful for colonoscopist to diagnose the pathological types.

Key words: early colorectal cancer, colorectal precancerous lesions, inflammation markers, systemic immune-inflammation index