Analysis Of Related Factors Between Simple Lung Metastasis And Simple Liver Metastasis After Radical Resection Of Rectal Cancer

Objective: To investigate the relationship between the first metastasis site and clinicopathological features,immunohistochemistry and gene detection after radical resection of rectal cancer.To analysis whether the site of the first postoperative metastasis of rectal cancer can be determined according to these related factors,and to guide the postoperative monitoring.Methods: By collecting the clinical data of patients with colorectal cancer after radical resection of solstice on January 1,2015 and November 1,2019 in Chifeng Municipal Hospital,the patients were divided into liver metastasis alone group and lung metastasis alone group according to the site of metastasis after disease recurrence.In strict accordance with the admission and discharge criteria,there were 55 patients in lung metastasis alone group and 28 patients in liver metastasis alone group.The differences in clinicopathological characteristics,immunohistochemistry and gene detection between the two groups were analyzed.Logistic multivariate regression model was used to analyze the related factors affecting the site of the first metastasis in patients with rectal cancer after radical resection.Results:1.A total of 83 patients undergoing radical resection of rectal cancer were included in this study,including 55 patients in the group with lung metastasis alone(mean age60.16±12.06 years old,male to female ratio 1.62:1),and 28 patients in the group with liver metastasis alone(mean age 59.93±8.95 years old,male to female ratio2.11.1).Single factor statistical analysis: After radical resection of rectal cancer patients with lung metastasis alone and liver metastasis alone,there were no significant statistical differences in gender,age,tissue type,degree of differentiation,depth of invasion,lymph node metastasis,TNM stage,EGFR and MMR(P>0.05),and there were statistically significant differences between the two groups in the site of primary tumor,the presence of nerve invasion,and the mutation status of KRAS(P < 0.05),suggesting that the location of the first metastasis in patients after radical resection of rectal cancer is related to the location of the primary tumor(above the peritoneal retroline vs below the peritoneal retroline),the presence of nerve invasion and the mutation status of KRAS2.Logistic multivariate regression model analysis showed that primary tumor location and KRAS mutation status were independent predictors of pure lung metastasis and pure liver metastasis after radical resection of rectal cancer(P<0.05),but the presence of nerve invasion was not an independent predictor of pure lung metastasis or pure liver metastasis after radical resection of rectal cancer(P>0.05)Conclusion: Primary tumor location and KRAS mutation status can be used as independent predictors of pure lung metastasis and pure liver metastasis after radical resection of rectal cancer.Compared with patients above the peritoneal retrofold line,patients below the peritoneal retrofold line are more likely to develop simple lung metastasis.The incidence of lung metastasis was higher in patients with KRAS mutation than in patients with KRAS wild-type.