The latest generation of fecal immunochemical tests allows for quantitation of hemoglobin in feces, allowing for selection of optimal cut-off concentrations.
Dr Josep Auge and colleagues from Spain investigated whether individuals with positive results from quantitative fecal immunochemical tests, in combination with other factors, could be identified as being at greatest risk for advanced colorectal neoplasia.
In a retrospective study, the researchers analyzed data from a consecutive series of 3109 participants with positive results from fecal immunochemical tests included in the first round of the Barcelona colorectal cancer screening program, from 2009 through 2012.
All participants underwent colonoscopy and were assigned to groups with any advanced colorectal neoplasia or with nonadvanced colorectal neoplasia.
|Risk for advanced colorectal neoplasia increased almost 12-fold in the highest category |
Median fecal hemoglobin concentrations were significantly higher in participants with advanced colorectal neoplasia compared with participants with nonadvanced colorectal neoplasia.
The team found that positive predictive values for advanced colorectal neoplasia, determined using arbitrary fecal hemoglobin concentrations, differed with sex and age.
The research team identified sex, age, and fecal hemoglobin concentration as independent predictive factors for advanced colorectal neoplasia.
Combining these factors, the team identified 16 risk categories associated with different probabilities of identifying advanced colorectal neoplasia.
Risk for advanced colorectal neoplasia increased almost 12-fold among individuals in the highest category compared with the lowest category.
The team observed that positive predictive values ranged from 21% to 76%.
Dr Auge's team concludes, "Fecal hemoglobin concentration, in addition to sex and age, in individuals with positive results from fecal immunochemical tests can be used to stratify probability for the detection of advanced colorectal neoplasia."
"These factors should be used to prioritize individuals for colonoscopy examination."