Targeting very small tumors or precancerous polyps does little to significantly reduce the incidence of colorectal cancer and results in extremely high costs and a large proportion of adverse effects a new study shows in the online edition of CANCER, which will appear in the June 1 print edition.
In the analysis the researchers found that removing malignant polyps of 6 mm (less than 0.25 in.) or greater, so-called diminutive polyps, produced the best estimated value per life-year gained and with fewer complications.
Most healthcare advocates believe that effective screening through increased use of any of several available tests is the key to reducing deaths from colorectal cancer, the third leading cause of cancer death in both men and women. Despite the availability of effective screening tests, screening rates remain low and colorectal cancer-related deaths remain high.
In this model of 100,000 persons over 50 years old, CTC with colonoscopy follow-up of polyps greater than 5 mm was the most cost-effective screening test. The cost-benefit analysis of colorectal screening methods was conducted by Dr. Perry Pickhardt, a radiologist from the University of Wisconsin, who collaborated with Dr. Cesare Hassan, a gastroenterologist from Rome.
"CTC (CT colonography) with nonreporting of diminutive lesions is the most cost-effective and safest screening option available," the authors wrote. "Providing additional effective yet distinct screening options like CTC could encourage more adults to undergo screening and increase overall compliance with screening (for colorectal cancer)."
Optical colonoscopy and flexible sigmoidscopy have been the primary screening tools for the last few decades but are associated with complications – from abdominal pain to life-threatening bowel perforation and bleeding.
Working up these small, almost always benign polyps with colonoscopy caused considerable complications. The study found almost half of all colonoscopy-related complications were attributable to work-up of diminutive lesions. Furthermore, targeting these lesions did not improve screening effectiveness, reducing colorectal cancer incidence by only 1.3 percent, according to the CANCER study.
Virtual colonoscopy, or CT colonography, has arisen as a potentially effective colorectal screening tool. Using x-rays and imaging software to develop two- and three-dimensional images of the gastrointestinal tract, it has fewer adverse effects and is better tolerated by patients. Recent studies using new methods have demonstrated that the test is very sensitive for cancer and could be an effective screening option for patients.