Abstract: Objective To investigate the correlation between tumor location,body mass index(BMI) and prognosis of colorectal cancer(CRC) patients after radical resection.Methods The clinical data of 102 patients with CRC who underwent radical resection in the hospital from June 2015 to June 2017 were retrospectively analyzed.The 5year survival of the patients was observed,and the patients were divided into a death group and a survival group accordingly.Baseline data,tumor location,and BMI were compared between the two groups.To explore the prognostic factors of CRC patients after radical resection and the relationship between tumor location,BMI and prognosis of patients.The predictive power of tumor location and BMI on the 5year prognosis of patients was analyzed,and the 5year survival of patients with different tumor locations and BMI was observed.Results In this group of 102 CRC patients who underwent radical resection,32 died within 5 years and were classified as the death group;70 patients survived for 5 years and were classified as the survival group.There were significant differences in pathological stage,tumor differentiation,lymph node metastasis,tumor location and BMI between the two groups(P＜0.05).COX regression analysis showed that pathological stage,tumor differentiation,lymph node metastasis,tumor location,and BMI were the prognostic factors of death in patients with CRC after radical resection(P＜0.05).After further adjusting for confounding factors such as pathological stage,tumor differentiation,lymph node metastasis and other confounding factors through COX regression analysis,it was found that tumor location and BMI were still significantly correlated with the prognosis and death of patients(P＜0.05).The receiver operating characteristic(ROC) curve showed that the area under the curve(AUC) of tumor location combined with BMI to predict the 5year death of patients was 0.822,which was higher than tumor location or BMI alone.The sensitivity and the specificity of tumor location combined with BMI was 68.75% and 84.29%,respectively.The Kaplan-Meier curve analysis showed that the 5year survival rate of patients with rectal tumor was higher than that of patients with right and left colon(Log-Rank χ2=7.530，P=0.023),the 5year survival rate of patients with left colon tumor was higher than that of patients with right colon(Log-Rank χ2＝5.362,P＝0.042),and the 5year survival rate of patients with lower BMI was higher than that of patients with higher BMI patients(Log-Rank χ2=24.043,P＜0.001).Conclusion Tumor location and BMI are closely related to the prognosis of patients with CRC after radical resection.The combination of tumor location and BMI has a high efficacy in predicting the prognosis of patients with death,which can provide a certain reference for prognosis evaluation.

Key words: tumor site, body mass index, radical resection of colorectal cancer, prognosis