The localisation of cancer in the sigmoid, rectum or rectosigmoid junction using endoscopy or radiology-What is the...

There is a difference in approach between colon and rectal cancer.

EVALUATE THE METHODS OF LOCALISATION: endoscopy and radiology.

Patients with cancer in the sigmoid or rectum diagnosed with endoscopy, were included. Patients underwent additional radiological examinations. The resection specimen served as the gold standard. A tumour surrounded by serosa was considered a sigmoid cancer, surrounded by perirectal fat, than it was rectal cancer. If the frontal edge of the tumour showed serosa and the dorsal plane perirectal fat than the tumour was located in the "rectosigmoid".

A total of 182 cancers were diagnosed. Of the 128 cancers with gold standard, endoscopy had the correct localisation in 112 (87.5%), and radiology in 114 (90.5%) cases. Concordance between both techniques was present in 80%. In 28 cases there was discordance. Radiology located 10 sigmoidal cancers wrongly in the rectum. One rectal cancer was placed in the sigmoid. In 16 cases the endoscopic localisation wrongly was the sigmoid. Sensitivity and specificity for endoscopy in sigmoidal cancer is 100% and 77% respectively, for rectal cancer 77% and 100%. Sensitivity of radiology for cancer in the sigmoid and rectum are 80% and 98% respectively. Specificity for both cancers is 98% and 80% respectively.

The endoscopist and the radiologist should not be too overconfident with localisation of the tumour in cases of high rectal or low sigmoidal cancer.