The Clinical Validity of Family History in Risk Classification of Colorectal Cancer

Abstract

Objective: To determine the clinical validity of family history (FH) in colorectal cancer (CRC) risk classification. Methods: The Assessment of Risk of Colon Tumors In Canada case-control dataset was used to develop regression models associating risk factors with CRC in Ontario adults. Two regression models (‘clinically-driven’ based on a previously published tool, and data-driven) examined discrimination between CRC cases and controls, with and without the inclusion of FH as a risk variable. Discrimination was assessed using the area under the receiver operator characteristics curve. Results: For males, with the addition of FH, there were statistically significant yet quantitatively modest improvements in both models (3.7% clinically-driven, 6.8% data-driven). For females, while FH was a statistically significant predictor of CRC status in the data-driven model, the improvement in discrimination was not significant in either model. Conclusion: FH provides very small improvement in model discrimination beyond other standard CRC risk factors.