Fecal immunochemical testing (FIT) is increasingly used in colorectal cancer (CRC) screening but has a less than perfect sensitivity.
Combining risk stratification, based on established risk factors for advanced neoplasia, with the FIT result for allocating screenees to colonoscopy could increase the sensitivity and diagnostic yield of FIT-based screening.
Dr Inge Stegeman and colleagues from the Netherlands explored the use of a risk prediction model in colorectal cancer screening.
The researchers collected data in the colonoscopy arm of the Colonoscopy or Colonography for Screening study, a multicenter screening trial.
For this study 6600 randomly selected, asymptomatic men and women between 50 years and 75 years of age were invited to undergo colonoscopy.
|78% completed the questionnaire and FIT|
Screening participants were asked for one sample FIT, and to complete a risk questionnaire prior to colonoscopy.
Based on the questionnaire data and the FIT results, the team developed a multivariable risk model with the factors including total calcium intake, family history, age and FIT result.
The research team evaluated goodness-of-fit, calibration and discrimination, and compared it with a model based on primary screening with FIT only.
Of the 1426 screening participants, 78% completed the questionnaire and FIT.
Of these, 9% had advanced neoplasia.
The risk based model significantly increased the goodness-of-fit compared with a model based on FIT only.
The team found that discrimination improved significantly with the risk-based model.
By offering colonoscopy to the 102 patients at highest risk, rather than to the 102 cases with a FIT result >50 ng/mL, 5 more cases of advanced neoplasia would be detected.
Dr Stegeman's team concludes, "Adding risk based stratification increases the accuracy FIT-based colorectal cancer screening and could be used in preselection for colonoscopy in colorectal cancer screening programs."