Preoperative colonoscopy through the colonic stent in patients with colorectal cancer obstruction

AIM:To evaluate the feasibility of a preoperative colonoscopy through a self-expendable metallic stent(SEMS)and to identify the factors that affect complete colonoscopy.METHODS:A total of 48 patients who had SEMS placement because of acute malignant colonic obstruction underwent preoperative colonoscopy.After effective SEMS placement,patients who showed complete resolution of radiological findings and clinical signs of acute colon obstruction underwent a standard bowel preparation.Preoperative colonoscopy was then performed using a standard colonoscope.If the passage of colonoscope was not feasible gastroscope was used.After colonoscopy,cecal intubation time,grade of bowel preparation,tumor location,stent location,presence of synchronous polyps or cancer,damage to colonoscopy and bleeding,and stent migration after colonoscopy were recorded.RESULTS:Complete evaluation with colonoscope was possible in 30 patients(62.5%).In this group,adenoma was detected in 13 patients(43.3%).The factors that affected complete colonoscopy were also analyzed:Tumor location at an angle;stent placement at an angle;and stent expansion diameter,which affected complete colonoscopy significantly.However in multivariate analysis,stent expansion diameter was the only significant factor that affected complete colonoscopy.Complete evaluation using additional gastroscope was feasible in 42 patients(87.5%).CONCLUSION:Preoperative colonoscopy through the colonic stent using only conventional colonoscope was unfavorable.The narrow expansion diameter of the stent may predict unfavorable outcome.In such a case,using small caliber scope should be considered and may expect successful outcome.

Different risk factors for advanced colorectal neoplasm in young adults

AIM: To compare the risk of developing advanced colorectal neoplasm(ACRN) according to age in Koreans.METHODS: A total of 70428 Koreans from an occupational cohort who underwent a colonoscopy between 2003 and 2012 at Kangbuk Samsung Hospital were retrospectively selected. We evaluated and compared odds ratios(OR) for ACRN between the young-adults(YA < 50 years) and in the older-adults(OA ≥ 50 years). ACRN was defined as an adenoma ≥ 10 mm in diameter, adenoma with any component of villous histology, high-grade dysplasia, or invasive cancer.RESULTS: In the YA group, age(OR = 1.08, 95%CI: 1.06-1.09), male sex(OR = 1.26, 95%CI: 1.02-1.55), current smoking(OR = 1.37, 95%CI: 1.15-1.63), family history of colorectal cancer(OR = 1.46, 95%CI: 1.01-2.10), diabetes mellitus related factors(OR = 1.27, 95%CI: 1.06-1.54), obesity(OR = 1.23, 95%CI: 1.03-1.47), CEA(OR = 1.04, 95%CI: 1.01-1.09) and low-density lipoprotein-cholesterol(OR = 1.01, 95%CI: 1.01-1.02) were related with an increased risk of ACRN. However, age(OR = 1.08, 95%CI: 1.06-1.09), male sex(OR = 2.12, 95%CI: 1.68-2.68), current smoking(OR = 1.38, 95%CI: 1.12-1.71), obesity(OR = 1.34, 95%CI: 1.09-1.65) and CEA(OR = 1.05, 95%CI: 1.01-1.09) also increased the risk of ACRN in the OA group.CONCLUSION: The risks of ACRN differed based on age group. Different colonoscopic screening strategies are appropriate for particular subjects with risk factors for ACRN, even in subjects younger than 50 years.

Prognostic value of 18-fluorodeoxyglucose positron emission tomography-computed tomography in resectable colorectal cancer

AIM:To assess the prognostic value of preoperative 18 fluorodeoxyglucose positron emission tomography(FDG-PET)/computed tomography(CT) in patients with resectable colorectal cancer.METHODS:One hundred sixty-three patients with resectable colorectal cancer who underwent FDG-PET/CT before surgery were included.Patient data including pathologic stage at presentation,histology,treatment,disease-free survival and the maximum standardized uptake value(SUVmax) of the primary tumor on FDG-PET/CT were retrospectively analyzed.Median follow up duration was 756(range,419-1355).The primary end point was disease-free survival.RESULTS:Twenty-five of 163 patients(15.3%) had recurrences.The median SUVmax values of the recurrence and no-recurrence groups were 8.9(range,5-24) and 8.2(range,0-23,P = 0.998).Receiver operating characteristic(ROC) curve analysis showed no significant association between SUVmax and recurrence(area under the curve = 0.5,P = 0.998,95% CI:0.389-0.611).Because a statistically significant value was not found,SUVmax was dichotomized at its median of 8.6.The disease-free survival curve was analyzed using the median SUVmax(8.6) as the cut off.Univariate and multivariate analysis did not provide evidence that disease-free survival rates for the subgroups defined by the median SUVmax were significantly different(P = 0.52,P = 0.25).CONCLUSION:Our study suggests that the high FDG uptake of primary mass in resectable colorectal cancer doesn't have a significant relationship with tumor recurrence and disease-free survival.