Cancer Research Lab

Following surgery for colon cancer, colonoscopy is useful in detecting recurrence and other cancer and adenomas, and is tied to improved survival, researchers report in the March issue of Clinical Gastroenterology and Hepatology.

“The results of our study provide additional evidence that colorectal cancer survivors benefit from surveillance with colonoscopy,” lead investigator Dr. Stephen J. Rulyak said.

Dr. Rulyak of the University of Washington, Seattle and colleagues note that the utility of colonoscopy in the follow-up of colorectal cancer survivors is uncertain, and findings of surveillance colonoscopy are not well-characterized.

In order to help do so, the researchers studied data on 1002 patients with colorectal cancer who had undergone surgical resection.

Five-year survival was higher (76.8%) for patients who had at least one follow-up exam than was the case for patients who did not undergo follow-up (52.2%).

The estimated influence on survival was similar whether the initial examination took place within 18 months or at up to 60 months of diagnosis.

After adjustment, colon examination was a significant independent predictor of decreased overall mortality (hazard ratio, 0.58). Being female and receiving chemotherapy were also associated with reduced risk (hazard ratio, 0.50).

Following examination, 20 patients were diagnosed with a second colorectal cancer. Of these cancers, 9 were detected within 18 months of initial cancer diagnosis. Advanced neoplasia was more common in patients followed up at 36 to 60 months after diagnosis compared with those followed up within 18 months.

“Our results,” Dr. Rulyak concluded, “support recently published guidelines that recommend initial surveillance colonoscopy should be performed at one year after colon resection because of the significant risk of additional cancers and polyps found in these patients.”