Doctors from Memorial Sloan Kettering, Mt. Sinai and several other major medical centers throughout the country just published their long-term findings from the National Polyp Study (NPS) in the prestigious New England Journal of Medicine: http://www.nejm.org/doi/full/10.1056/NEJMoa1100370. They prospectively evaluated 2600 patients found to have adenomatous polyps at the time of screening colonoscopy for colorectal cancer (CRC) originally between 1980 and 1990. All patients in this group had their polyps removed by a process called polypectomy at the time of colonoscopy. The researchers followed these patients for a median of almost 16 years, recorded their rate of subsequent death from CRC, and compared it to the expected death rate from CRC in the general public.
Among the group that underwent colonoscopy with removal of their polyps, 12 people died as a result of CRC. This number represented a 53% reduction from the expected number of 25 deaths from CRC in the general population. The authors concluded that “colonoscopic removal of adenomatous polyps prevents death from colorectal cancer.”
Over the past year, there has been considerable controversy about the ability of certain cancer screening tests to effectively save lives. Relative to PSA blood tests or mammograms, colonoscopies are more invasive, more expensive, and less widely available. Many patients dread the procedure itself as well as the bowel preparation required for a good evaluation by the gastroenterologist or surgeon. However, there is significant data in the medical literature to support its value. Although this NPS study was relatively small and not a randomized clinical trial, it was well done and shows a large relative survival benefit. At least for patients with adenomatous polyps, it’s currently hard to argue against the potential survival benefit provided by colonoscopy.
- Patrick Maguire MD