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.

Primary signet ring cell carcinoma of the appendix:A rare case report and our 18-year experience

Primary adenocarcinoma of the appendix is a rare ma-lignancy that constitutes < 0.5% of all gastrointestinal neoplasms. Moreover, primary signet ring cell carci-noma of the appendix is an exceedingly rare entity. We have encountered 15 cases of primary appendiceal cancer among 3389 patients who underwent appen-dectomy over the past 18 years. In the present report, we describe a rare case of primary signet ring cell carcinoma of the appendix with ovarian metastases and unresectable peritoneal dissemination occurring in a 67-year-old female patient. She underwent ap-pendectomy and bilateral salpingo-oophorectomy with a laparoscopy procedure. She then received palliative systemic chemotherapy with 12 cycles of oxaliplatin, 5-flurorouracil, and leucovorin (FOLFOX-4). The patient currently is well without progression of disease 12 mo after beginning chemotherapy.

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.

Incidental focal colorectal ^(18)F-fluorodeoxyglucose uptake on positron emission tomography/computed tomography

AIM: To assess the clinical significance of incidental focal colorectal 18 F-fluorodeoxyglucose ( 18 F-FDG) uptake on 18 F-FDG-positron emission tomography/computed tomography (PET/CT). METHODS: The records of all the cases which had undergone colonoscopy after PET/CT within a two weeks interval were reviewed. Adenomas were considered advanced when they were villous, ≥ 10 mm in size, or had high-grade dysplasia. Colorectal cancers and advanced adenomas are collectively referred to as advanced colorectal neoplasms. Receiver-operating characteristic curve analysis was used to determine thesignificant predictive maximum standardized uptake value (SUVmax) cutoff value for advanced colorectal neoplasms and cancer. RESULTS: Ninety-five colorectal lesions matched the site of incidental focal colorectal 18 F-FDG uptake on PET/CT and 146 did not. Colonoscopy showed advanced colorectal neoplasms corresponding to the site of 18 F-FDG uptake in 49 of the 95 (51.5%) lesions with incidental uptake. Of the lesions without incidental uptake, only 6 of 146 (4.1%) had advanced colorectal neoplasms on colonoscopy, indicating a statistically significant difference between the two groups (P < 0.001). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of incidental focal 18 F-FDG uptake in identifying advanced colorectal neoplasms were 89.1%, 75.3%, 51.6%, 95.9%, and 78.4%, respectively. In detecting only CRC, these values were 89.2%, 69.6%, 34.7%, 97.3%, and 72.6%, respectively. The significant SUVmax cutoff value for advanced colorectal neoplasms (area under the curve 0.755, P < 0.001) was 4.35, with a sensitivity, specificity, PPV, NPV, and accuracy of 75.5%, 65.2%, 69.8%, 71.4% and 70.5%, respectively. For CRC, 5.05 was the significant SUVmax cutoff value (area under the curve 0.817, P < 0.001), with a sensitivity, specificity, PPV, NPV, and accuracy of 84.8%, 71.0%, 80.9%, 89.8%, and 75.8%, respectively. CONCLUSION: The presence of incidental focal colorectal 18 F-FDG uptake on PET/CT with a SUVmax ≥ 4.35 increases the likelihood of an advanced colorectal neoplasm.