Development and validation of a scoring system to identify individuals at high risk for advanced colorectal neoplasms who should undergo colonoscopy screening

Abstract

Background & aims: Screening the population for colorectal cancer (CRC) by colonoscopy could reduce the disease burden. However, targeted screening of individuals at high risk could increase its cost effectiveness.

Methods: We developed a scoring system to identify individuals with at least 1 advanced adenoma, based on easy-to-collect risk factors among 7891 participants of the German screening colonoscopy program. The system was validated in an independent sample of 3519 participants. Multiple logistic regression was used to develop the algorithm, and the regression coefficient-based scores were used to determine individual risks. Relative risk and numbers of colonoscopies needed for detecting one or more advanced neoplasm(s) were calculated for quintiles of the risk score. The predictive ability of the scoring system was quantified by the area under the curve.

Results: We identified 9 risk factors (sex, age, first-degree relatives with a history of CRC, cigarette smoking, alcohol consumption, red meat consumption, ever regular use [at least 2 times/wk for at least 1 y] of nonsteroidal anti-inflammatory drugs, previous colonoscopy, and previous detection of polyps) that were associated significantly with risk of advanced neoplasms. The developed score was associated strongly with the presence of advanced neoplasms. In the validation sample, individuals in the highest quintile of scores had a relative risk for advanced neoplasm of 3.86 (95% confidence interval, 2.71-5.49), compared with individuals in the lowest quintile. The number needed to screen to detect 1 or more advanced neoplasm(s) varied from 20 to 5 between quintiles of the risk score. In the validation sample, the scoring system identified patients with CRC or any advanced neoplasm with area under the curve values of 0.68 and 0.66, respectively.

Conclusions: We developed a scoring system, based on easy-to-collect risk factors, to identify individuals most likely to have advanced neoplasms. This system might be used to stratify individuals for CRC screening.

Keywords: Average-Risk Population; Colorectal Neoplasm; Prediction; Screening.