Some patients receive repeat colonoscopies too soon, and some elderly get unnecessary ones
Many patients receive repeat colonoscopies more quickly than are recommended by screening guidelines, increasing the risk that they will have rare, but significant, adverse outcomes from the tests, researchers reported this week. In a separate study, another group of researchers showed that many elderly who are sick or debilitated from other illnesses receive colonoscopies despite the fact that the procedures are probably not beneficial and may cause problems.
Colonoscopies involve inserting a telescope-like instrument through the rectum to examine the interior of the small and large bowels so that doctors can look for polyps that are a precursor of colorectal cancer. If polyps are found, they can be snipped out during the procedure, sharply reducing the risk of progression to cancer. The technique is a valuable screening tool for colorectal cancers and sharply reduces the incidence of the disease. But the procedure costs thousands of dollars, preparation for it is nasty because of the need to eliminate all fecal matter from the bowels, and there is about a one in 1,000 risk of damaging the intestines during the procedure, which can cause hospitalizations and has led to deaths.
As a result, national health authorities recommend that colonoscopies be repeated only every 10 years if no problems are found on the original test. More frequent tests are recommended, however, for patients with a family history of the disease or in whom polyps were previously found. Most insurance companies, and Medicare, refuse to pay for the early repeat tests unless there is a specific medical indication.
About 100,000 Americans will be diagnosed with colon cancer this year and another 40,000 with rectal cancer.
In the first study, Dr. James S. Goodwin of the University of Texas Medical Branch in Galveston and his colleagues examined records for about 5% of Medicare patients enrolled in the program from 2000 through 2008, age 66 or older, who had normal results on their first colonoscopy. The researchers reported in the Annals of Internal Medicine that they identified 24,071 patients who had a negative result from the screening test. The team found that 23.5% of the patients had a followup colonoscopy within seven years, despite the lack of any medical indication for the procedure. Surprisingly, and in contradiction to its rules, Medicare paid for all but 2% of the repeat procedures. Patients with other health problems and those seen in high-volume colonoscopy centers were more likely to be retested, as well as those in certain parts of the country, such as the mid-Atlantic states. The early repeat tests in high-volume centers, the researchers said, suggested a financial incentive for the procedures rather than a medical one.
Another way to screen for colorectal cancers is the fecal occult blood test, commonly abbreviated FOBT. The test, generally performed yearly, checks for the presence of blood in stool. If blood is observed, patients are typically sent to have a followup colonoscopy. But because colon cancers are generally slow growing, many physicians argue that patients who have debilitating illnesses or who are not likely to survive for extended periods can be spared the tests.
Dr. Christine E. Kistler of the University of North Carolina at Chapel Hill and her colleagues studied 212 patients, age 70 and over, at VA medical centers who had a positive outcome on an FOBT. More than half of the patients (118) had a colonoscopy, while the rest did not. All the patients were followed for seven years.
Among the 118 patients who had a colonoscopy, physicians found 34 significant adenomas (a precursor to tumors) and six cases of cancer. About 10% of the patients developed complications from the colonoscopy or from the cancer treatment. Among those who did not receive a colonoscopy, three died of colorectal cancer within five years and 46% died of other causes. “If you are going to die in five years, why should we subject you to colonoscopies and biopsies?” Kistler said.
Durado Brooks, director of prostate and colorectal cancers at the American Cancer Society, hailed the studies, noting that many physicians order repeat tests out of a fear of missing a tumor. Such physicians also underestimate the risks of the procedure, especially for the elderly. Meanwhile, while resources are being wasted on such unneeded repeat screenings, about half of those who should be getting the tests never receive them.
