Endoscopists who detect tumors or polyps (adenomas) at a higher rate during colonoscopy screening for colorectal cancer tend to produce a lower risk for interval cancer among their patients, according to a study published in the New England Journal of Medicine.

Colon cancer is the second leading cause of cancer death in the United States. If detected and treated early, colorectal cancer is highly curable. Screening for colorectal cancer is recommended starting at the age of 50 for individuals at average risk of developing the disease and earlier for those at higher risk. Several screening tests are available, including the fecal occult blood test (FOBT), sigmoidoscopy, double-contrast barium enema, and colonoscopy.

During a colonoscopy, a lighted tube with an attached camera is inserted into the rectum and through the colon. Colonoscopy is performed by an endoscopist, a healthcare professional who specializes in such procedures.

Interval cancers are cancers that develop in the period between screening colonoscopy and follow-up, or surveillance, colonoscopy. A factor that may influence a patient’s risk of developing an interval cancer is the endoscopist’s rate of detection of adenomas during screening colonoscopy.

To evaluate whether the rate at which an endoscopist detects adenomas can predict a patient’s risk of interval colorectal cancer, researchers evaluated information about 186 endoscopists and 45,000 patients who had undergone colonoscopy screening.

Adenoma detection rate was calculated for each endoscopist, and was defined as the proportion of screened subjects in whom at least one adenoma was identified.

• 42 interval cancers were identified.
• The endoscopist’s rate of adenoma detection during screening colonoscopy was significantly associated with the risk of interval cancers: patients undergoing colonoscopy performed by an endoscopist with a detection rate of more than 20% had a significantly lower risk of interval cancers compared with patients whose endoscopists had a detection rate of less than 20%.

It appears that an endoscopist’s rate of detection of adenomas during screening colonoscopy may be a measure of colonoscopy quality. Endoscopists who have a higher rate of adenoma detection tend to produce a lower risk for interval cancers among their patients.

Reference: Kaminski MF, Regula J, Kraszewska E, et al. Quality indicators for colonoscopy and the risk of interval cancer. New England Journal of Medicine. 2010 May 13;362(19):1795-803.

Tags: Colon Cancer, News Tips and Features, Rectal Cancer, Screening/Prevention Colon Cancer, Screening/Prevention Rectal Cancer