Analysis Of Risk Factors For Lymph Node Metastasis In Submucosal Invasive Colorectal Cancer

Objective:Submucosal invasive colorectal cancer(SICRC)refers to the malignant tumor cells directly infiltrate into the submucosal layer through the muscularis mucosa without involving the muscularis propria,regardless of lymph node status.With the vigorous development of endoscopic diagnosis and treatment technology in China,the endoscopic treatment of early colorectal cancer(ECC)has also gradually emerged,becoming a new treatment measure to replace surgery and providing a new option for patients.The potential risk of lymph node metastases associated with SICRC is still debated,and the presence or absence of lymph node metastases is critical to the selection of appropriate therapeutic measures.The purpose of this study was to investigate the high-risk factors of lymph node metastasis associated with SICRC,and to provide guidance for patients with high-risk lymph node metastasis to undergo radical resection immediately after endoscopic treatment.Methods: All medical records of 13,629 colorectal cancer patients who underwent colorectal cancer resection and lymph node dissection in Qingdao University Affiliated Hospital from January 2012 to September 2020 were selected.According to the inclusion and exclusion criteria,293 eligible SICRC patients were finally screened and included in the study.The clinical features,endoscopic and histopathological features of tumors were recorded separately for all patients.The lymph node metastasis rate of each factor was calculated according to the ratio of the number of lymph node metastasis in each category to the total number of each category.SPSS software was used for statistical analysis,Chi-square test and Fisher’s exact test were used for univariate analysis of the correlation between each feature and lymph node metastasis in SICRC patients,and multivariate Logistic regression model was used to analyze the independent risk factors for lymph node metastasis in SICRC patients.Results: A total of 293 SICRC patients were collected and included in the final study,of which 32 had lymph node metastasis,and the lymph node metastasis rate was 10.9%.There were 175 males,accounting for 59.7%,and 118 females,accounting for 40.3%,with a male-to-female ratio of 1.5:1.Aged 35-94 years old,mean(64.7±10.7)years old.Univariate analysis showed that gender(P=0.421),age(P=0.0821),history of hypertension(P=0.872),history of coronary heart disease(P=1.000),history of diabetes(P=0.414),history of smoking(P=0.702),drinking history(P=0.881),family history(P=0.838),BMI(P=0.454),CEA level(P=0.920),tumor location(P=0.599),tumor size(P=0.347),whether combined polyps(P=0.254)were not associated with lymph node metastasis in patients with SICRC.Macroscopic type(P=0.007),presence of ulcer(P<0.0019),mucosal invasion depth(P<0.001),lymphovascular invasion(P<0.001),perineural invasion(P<0.001),differentiation(P=0.003)were associated with lymph node metastasis in SICRC patients.Multivariate Logistic regression analysis showed the presence of ulcers(OR=4.664,1.635-13.307),mucosal invasion depth ≥1000μm(OR=6.569,2.306-18.711),lymphovascular invasion(OR=8.282,2.034-33.723),perineural invasion(OR=6.273,1.466-26.849)and poorly differentiated(OR=10.666,1.073-106.005)were closely related to lymph node metastasis and were independent risk factors for lymph node metastasis in SICRC patients.Grouping was based on independent risk factors for lymph node metastasis identified in this study,the results showed that the lymph node metastasis rate of the no-risk group was 1.5%,the low-risk group was 9.8%,and the intermediate-risk group was 48%,the lymph node metastasis rate in the high-risk group was 100%.Conclusion: 1.The presence of ulcers,mucosal invasion depth ≥1000μm,lymphovascular invasion,perineural invasion and poor differentiation were risk factors for lymph node metastasis in patients with SICRC.2.With the increase of risk factors,the risk of lymph node metastasis increases significantly.3.If multiple high-risk factors for lymph node metastasis are found after endoscopic treatment,radical resection should be added immediately to reduce the recurrence rate.