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.

The clinical signifi cance of circulating tumor cells in gastrointestinal cancer

Circulating tumor cells(CTCs)are originated from the primary tumor lesion into the blood stream.CTCs could lead to recurrence of gastrointestinal(GI)cancers,even after a curative resection and colonizing in the distant organs to facilitate tumor distant metastasis;however,it has been challenging in clinic to detect CTCs for a long time,such as detection methodology or molecular markers for identifi cation of CTCs.This review discussed the recent technical advances and biomarkers in the detection of CTCs and the molecular mechanism of CTC in cancer progression and metastasis.Moreover,novel concepts,such as cancer stem cells and epithelial-mesenchymal transition,could lead to CTCs and tumor progression and metastasis.Nevertheless,the involvement of CTCs varies greatly among cancer types in the GI and much remains to be learned.Thus,further study will provide more insightful information from a clinical and translational viewpoint to use CTCs for cancer early diagnosis or prediction of tumor recurrence and investigation of tumor progression and metastasis as well.