Two articles and an editorial in the Jan. 18, 2005, Annals of Internal Medicine discuss the fecal occult blood test (FOBT), a test for blood in the stool. Current screening recommendations are that adults over age 50 should take a six-sample FOBT test at home and return the stool samples to their physicians for interpretation. Positive tests should be followed up with a colonoscopy. Unfortunately, patients often do not complete the home FOBT tests, so doctors sometimes do a single FOBT test in the office.
A prospective study of 3,121 people without symptoms for colorectal cancer found that the single office-based FOBT missed advanced precancerous lesions 95 percent of the time (Article, p. 81). Researchers identified 284 people with colorectal cancer or large polyps likely to become cancer. Of these, only 4.9 percent had positive results on a single office-based FOBT, while 23.9 percent had positive results on the six samples taken at home.
In a national survey of 1,147 primary care physicians and 11,365 people eligible for colorectal cancer screening, 90 percent of the doctors reported using FOBT at least once per month and one-third of these reported using only a single FOBT rather than the home test (Article, p. 86). Nearly 30 percent of physicians reported they did not follow-up a positive FOBT with an immediate colonoscopy. About a quarter of the patients reported having FOBT, and one-third of these reported having only a single test in the office.
An editorial writer calls the two studies shocking and concludes that primary care physicians must reexamine their colorectal cancer screening practices (Editorial, p. 146).
2. Improving HDL Cholesterol Limited Progression of Heart Disease