In clinical practice, some physicians discontinue warfarin prior to fecal occult blood testing.
Anticoagulant use is associated with an increased risk of overt gastrointestinal bleeding.
However, the impact of warfarin on the positive predictive value of fecal occult blood testing is unknown.
Dr Edmund Bini and colleagues from New York prospectively studied patients taking warfarin referred for the evaluation of a positive fecal occult blood testing.
The researchers conducted the analysis during a 5-year period.
The team enrolled age- and gender-matched control subjects with a positive fecal occult blood testing not taking anticoagulants.
|83% of patients in the warfarin group had early cancers vs 50% of control subjects|
|American Journal of Gastroenterology|
The researchers obtained a detailed clinical history, and all subjects underwent colonoscopy and esophagogastroduodenoscopy.
The team identified lesions consistent with occult bleeding in 59% of the 210 patients in the warfarin group and 54% of the 210 control subjects.
More lesions were identified by colonoscopy in the warfarin group than in control subjects, at a rate of 36% vs 26%, respectively.
The team observed no difference in the frequency of lesions identified by esophagogastroduodenoscopy.
The researchers reported that the most common lesions identified by colonoscopy included adenomas of 1 cm in diameter in 16% of patients and colorectal carcinoma in 10%.
The team observed 16% of patients presenting with erosive gastritis and 11% with erosive duodenitis, the most frequent lesions found by esophagogastroduodenoscopy.
Among individuals with colorectal cancer, 83% of patients in the warfarin group had early cancers compared with 50% of control subjects.
Dr Bini's team concludes, “Warfarin use did not decrease the positive predictive value of fecal occult blood testing.”
“These findings suggest that warfarin should not be discontinued prior to fecal occult blood testing.”