Forward-viewing radial-array echoendoscope for staging of colon cancer beyond the rectum

AIM:To evaluate feasibility of the novel forward-viewing radial-array echoendoscope for staging of colon cancer beyond rectum as the first series.METHODS:A retrospective study with prospectively entered database.From March 2012 to February 2013,a total of 21 patients(11 men)(mean age 64.2 years)with colon cancer beyond the rectum were recruited.The novel forward-viewing radial-array echoendoscope was used for ultrasonographic staging of colon cancer beyond rectum.Ultrasonographic T and N staging were recorded when surgical pathology was used as a gold standard.RESULTS:The mean time to reach the lesion and the mean time to complete the procedure were 3.5 and 7.1min,respectively.The echoendoscope passed through the lesions in 13 patients(61.9%)and reached the cecum in 10 of 13 patients(76.9%).No adverse events were found.The lesions were located in the cecum(n=2),ascending colon(n=1),transverse colon(n=2),descending colon(n=2),and sigmoid colon(n=14).The accuracy rate for T1(n=3),T2(n=4),T3(n=13)and T4(n=1)were 100%,60.0%,84.6%and 100%,respectively.The overall accuracy rates for the T and N staging of colon cancer were 81.0%and52.4%,respectively.The accuracy rates among traversable lesions(n=13)and obstructive lesions(n=8)were 61.5%and 100%,respectively.endoscopic ultrasound and computed tomography had overall accuracy rates of 81.0%and 68.4%,respectively.CONCLUSION:The echoendoscope is a feasible staging tool for colon cancer beyond rectum.However,accuracy of the echoendoscope needs to be verified by larger systematic studies.