ATLANTA — Only about half the people who screen positive for blood in the stool during routine physical examinations are thoroughly checked for colorectal cancer, according to a Centers for Disease Control and Prevention study presented at the annual meeting of the American Society of Clinical Oncology.
Complete colon examinations were reported by just 71 (53.1%) of 136 participants who said they had an abnormal fecal occult blood test (FOBT) that was not done because of a specific problem or as a follow-up to an earlier test.
Twenty-two people said they had no colon evaluation at all. Another 16 people reported that their doctors ordered a repeat of the FOBT. Eight had sigmoidoscopy, and three had a barium enema. Twelve patients went on to surgery, and four patients did not know what, if anything, was done as a result of their abnormal FOBT.
“The follow-up to screening seems to be a black box,” Dr. Lisa C. Richardson said in an interview at the poster session where she presented the data. Dr. Richardson, a medical officer in the CDC's Division of Cancer Prevention and Control, reviewed the responses of 4,908 people who participated in the 2000 National Health Interview Survey Cancer Control Supplement, a nationally representative sample of households. Eighty percent said they had the FOBT screen for colorectal cancer.
She and CDC coinvestigator Zahava Berkowitz determined that 287 respondents said they had an abnormal FOBT result. Of these, 151 were excluded from the sample because their tests were prompted by a specific problem or were done to follow-up on an earlier exam. The remaining 136 patients screened positive during routine FOBT. Analysis of demographic factors showed that people were more likely to receive a complete colon examination if they were older than 65, reported excellent or very good health status, or had a college education.
“Some doctors don't trust the fecal occult blood test results. They don't think a whole colon examination is necessary,” she said, calling for greater efforts to educate physicians and patients about the importance of total colon examination after an abnormal FOBT.