Closer Look at Colorectal Cancer Screening
Reported January 19, 2005
(Ivanhoe Newswire) — A new study shows a single office-based stool blood test is a poor, but often used, screening test for colorectal cancer.
Current recommendations suggest adults over age 50 take a six-sample fecal occult blood test at home and return the stool samples to their physicians for interpretation. Positive tests necessitate a colonoscopy. However, patients often do not complete the home FOBT tests, so doctors sometimes do a single FOBT test in the office.
Researchers from Veterans Affairs Medical Centers studied more than 3,000 people without symptoms for colorectal cancer. They found the single office-based FOBT missed advanced pre-cancerous lesions 95 percent of the time, while 23.9 percent of these patients had positive results on the six samples they took at home.
The results of a national study show 90 percent doctors use FOBT at least once per month, and one-third of them use only that rather than patients using the home test. Nearly 30 percent of physicians report they did not follow up a positive FOBT with a colonoscopy.
Researchers conclude, “Single digital FOBT is a poor screening test for colorectal cancer and cannot be recommended as the sole test. If results of digital FOBT are negative, an at-home six-sample FOBT or other screening test should be performed.”
SOURCE: Annals of Internal Medicine, 2005;142:81-94