Quantitative fecal immunochemical tests identify individuals with colorectal cancer with greater levels of accuracy than guaiac tests.
Dr Thibaut Raginel and colleagues from France compared the performances of 2 fecal immunochemical tests in a population undergoing screening for colorectal cancer.
The research team collected fecal samples from 19,797 individuals in France who participated in a colorectal cancer screening program, from 2009 through 2011.
Samples were analyzed using the Magstream and OC Sensor fecal immunochemical tests, as well as the Hemoccult II guaiac test.
The doctors reported that colonoscopies were performed for patients with positive results from all 3 tests.
The cut-off values for levels of hemoglobin in buffer and stools were 55 ng/mL and 180 μg/g for the Magstream and 150 ng/mL, and 30 μg/g for the OC Sensor, respectively.
The doctors found that the results from the fecal immunochemical tests were compared with those from the guaiac test for cut-off values for stool samples, positivity rates, and the receiver operating characteristic curve values.
The numbers needed to screen and the numbers needed to scope to detect an advanced neoplasia were calculated.
|Numbers needed to screen were 66 for a 1-sample Magstream fecal immunochemical tests|
A positive test result was found in 1224 participants.
The research team reported 1075 underwent a colonoscopy examination.
Of these, 334 were found to have advanced neoplasia.
Considering the cut-off values associated with the positivity rate of Hemoccult II, the numbers needed to screen were 239 for Hemoccult II, 166 for a 1-sample Magstream fecal immunochemical tests, and 129 for a 1-sample OC Sensor fecal immunochemical tests.
The team found that the numbers needed to scope were 3.3, 2.3, and 1.8, respectively.
For the same false-positive rate as Hemoccult II, the true-positive rates for Magstream and OC Sensor fecal immunochemical tests were 0.65% and 0.90% respectively, compared with 0.42% for Hemoccult II.
The OC Sensor fecal immunochemical tests had a greater area under the receiver operating characteristic curve value than the Magstream fecal immunochemical tests.
Dr Thibaut's team commented "Based on results from a large, population-based study, the OC Sensor fecal immunochemical tests identifies patients with colorectal cancer with greater accuracy than the Magstream fecal immunochemical tests."