FOBT Accuracy Declines As Temperature Rises
Study finds colorectal cancer screening test less likely to detect cancer in summer compared to winter
WEDNESDAY, July 7 (HealthDay News) -- Fecal occult blood testing (FOBT) for the detection of colorectal cancer is significantly less accurate in the summer than in the winter, according to research published online July 5 in Gut.
Grazia Grazzini, M.D., of the Cancer Prevention and Research Institute in Florence, Italy, and colleagues examined data on hemoglobin (Hb) concentrations from FOBT over four seasons to determine whether ambient temperature has an effect on the test's effectiveness. They examined 199,654 FOBT results.
The researchers found a 17 percent lower probability of FOBT being positive in summer than in winter, a 0.7 percent reduction in the probability of a test being positive with each 1 degree Celsius rise in temperature, and a 13 percent lower probability of an advanced adenoma or cancer being detected in summer than in winter. The mean Hb concentrations were 27.6, 25.2, 29.2, and 29.5 for spring, summer, fall, and winter, respectively.
"This study showed that there is a significant fall in Hb concentration at higher ambient temperatures. These results will have important implications for the organization of immunochemical FOBT-based screening programs, particularly in countries with high ambient temperatures," the authors write.