False positives of fecal occult blood tests regarding colorectal cancer detection are common.
Dr Ja Sung Choi and colleagues from South Korea investigated the upper gastrointestinal (GI) condition confirmed by endoscopy in positive FOBT patients without advanced colorectal neoplasia, hemorrhoid, or colitis.
The team reviewed the collective data of 340 positive fecal occult blood tests patients who underwent both esophagogastroduodenoscopy and colonoscopy from 2005 to 2011.
Demographic data, effects of medications, including antiplatelet agents, nonsteroidal anti-inflammatory drugs, or warfarin on the results of fecal occult blood tests, presence or absence of gastrointestinal mucosal lesions confirmed by esophagogastroduodenoscopy and colonoscopy, and fecal occult blood tests titer in 552 positive fecal occult blood tests patients were analyzed.
|On colonoscopy, colorectal cancer was detected in 35 patients|
|Scandinavian Journal of Gastroenterology |
The doctors noted that on colonoscopy, colorectal cancer was detected in 35 patients, advanced adenoma in 22 patients.
“Negative colonoscopy” included no significant lesions and non-advanced adenomas.
The researchers found that in 243 patients with “negative colonoscopy”, esophagogastroduodenoscopy findings included 3 gastric cancers and 39 peptic ulcer diseases.
Gastric cancers were all found in patients who had no experience of esophagogastroduodenoscopy within 2 years.
However, the incidence of peptic ulcer disease was not different in patients with or without previous esophagogastroduodenoscopy within 2 years.
The doctors examined that 2 or more antiplatelet agents increased false positive rates of fecal occult blood tests.
Dr Choi's team concluded "Upper gastrointestinal evaluation is mandatory in patients with positive fecal occult blood testss and negative colonoscopy especially in patients without experience of esophagogastroduodenoscopy within 2 years."