Self-expanding metal stent placement and pathological alterations among obstructive colorectal cancer cases

BACKGROUND Experimental studies suggest that self-expanding metal stents(SEMSs)enhance the aggressive behavior of obstructive colorectal cancer.The influence of SEMS placement on pathological alterations remains to be elucidated.AIM To determine whether SEMS placement is associated with molecular or pathological features of colorectal carcinoma tissues.METHODS Using a nonbiased molecular pathological epidemiology database of patients with obstructive colorectal cancers,we examined the association of SEMS placement with molecular or pathological features,including tumor size,histological type,American Joint Committee on Cancer(AJCC)-pTNM stage,and mutation statuses in colorectal cancer tissues compared with the use of transanal tubes.A multivariable logistic regression model was used to adjust for potential confounders.RESULTS SEMS placement was significantly associated with venous invasion(P<0.01),but not with the other features examined,including tumor size,disease stage,mutation status,and lymphatic invasion.In both the univariable and multivariable models with adjustment for potential factors including tumor location,histological type,and AJCC-pT stage,SEMS placement was significantly associated with severe venous invasion(P<0.01).For the outcome category of severe venous invasion,the multivariable odds ratio for SEMS placement relative to transanal tube placement was 19.4(95%confidence interval:5.24–96.2).No significant differences of disease-free survival and overall survival were observed between SEMS and transanal tube groups.CONCLUSION SEMS placement might be associated with severe venous invasion in colorectal cancer tissue,providing an impetus for further investigations on the pathological alterations by SEMSs in colorectal cancer development.