Prediction of colonoscopic yield of neoplasia

To identify criteria which may predict yield of neoplasia at colonoscopy.

Clinicopathological characteristics of patients undergoing colonoscopy for either surveillance for neoplasia or investigation of colorectal symptoms were reviewed. Logistic regression was used to analyse risks for detection of adenoma and carcinoma.

A total of 493 consecutive colonoscopies was reviewed. In the surveillance group, risk for detection of adenoma was two-fold greater in the elderly (>65 years), in male patients and in those with a previous history of adenoma as opposed to carcinoma. In symptomatic patients, risk for detection of any neoplasm was three-fold greater in the elderly but was independent of gender and presence or absence of rectal bleeding.

These data support a case for prioritization of elderly patients for colonoscopy. The value of surveillance colonoscopy in preventing colorectal cancer appears greater in patients with a previous history of adenoma as opposed to carcinoma. Strict selection of patients with non-bleeding symptoms may result in a colonoscopic yield of neoplasia comparable to that in patients with rectal bleeding.