Occult blood test reduces colorectal cancer crises

A program of colorectal cancer screening using the fecal occult blood test (FOBT) appears to reduce emergency episodes of colorectal cancer and improves 30-day mortality rates, according to findings from a UK study published in the medical journal Gut.

A pilot study was conducted in central England "to determine the feasibility and acceptability of colorectal cancer (CRC) screening using postal FOBT within the UK on the 50-to-69 age group," write Dr. Steve J. Goodyear, of University Hospitals Coventry and Warwickshire NHS Trust, and colleagues.

FOBT involves the analysis of occult blood - blood that is not visible to the naked eye - in the feces, which may be a sign of CRC.

To assess the effects of the pilot program, the team reviewed CRC data on admissions from 1999 to 2004 in the region. The authors recorded data for the 5 years that included type of hospital admission, emergency surgery, 30-day mortality, and cancer stage.

In 1999, 60 of 204 CRC patients (29.4 percent) were admitted on an emergency basis. There was a steady decrease in the total number of CRC emergency admissions following the commencement of FOBT screening in the year, so by the fifth year only 32 (15.8 percent) of 202 CRCs (15.8 percent) were admitted as an emergencies, a statistically significant difference.

A statistically significant reduction in the 30-day mortality was also observed, from 48 percent in 1999 to 13 percent in 2004.

However, the most commonly diagnosed stage of colorectal cancer at emergency admission remained Dukes stage C carcinoma. Dukes stage C (on a scale of A to D) is characterized by penetration of the cancer into the bowel wall and spread to the lymph nodes.

The researchers postulate that the effect of the screening program over a fairly short interval reflects increases in the diagnosis of malignancies without symptoms, along with "increased public awareness of the symptoms of CRC, together with a change in attitudes and referral patterns of general practitioners."

SOURCE: Gut, February 2008.