Immunochemical FOBT May Be More Sensitive, Specific
Three-sample tests detect neoplasms in above-average risk people
TUESDAY, Feb. 20 (HealthDay News) -- Three-sample quantitative immunochemical fecal occult blood tests (FOBTs) have high sensitivity and specificity for detecting colorectal cancer and neoplasias in above-average risk people, according to the results of a study published in the Feb. 20 Annals of Internal Medicine.
Zohar Levi, M.D., of the Rabin Medical Center in Petach Tikva, Israel, and colleagues conducted a prospective, cross-sectional study of 1,000 patients, some of whom were asymptomatic but at increased risk for colorectal neoplasia, to measure the sensitivity and specificity of quantitative immunochemical FOBTs.
Ninety-one patients had clinically significant neoplasms identified by colonoscopy: cancer in 17 and advanced adenomas in 74. Using three immunochemical FOBTs and a specificity threshold of 75 ng/mL of buffer, sensitivity was 94.1 percent and specificity was 87.5 percent for cancer, and 67 percent and 91.4 percent for neoplasia. The authors caution that these results may not apply to those at average risk.
"The ability to choose different positivity thresholds makes quantitative immunochemical FOBT a potentially important test for colorectal cancer screening. It is a better test than guaiac-based FOBT for detecting occult bleeding and should be preferred to guaiac-based FOBT wherever FOBT is a component of a recommended screening strategy," writes Thomas Imperiale, M.D., of Indiana University Medical Center in Indianapolis, in an accompanying editorial.
One of the authors has received grants from the Eiken Chemical Company.