Construction and validation of a novel forecasting nomogram to the risk of colorectal adenomas: preventing colorectal cancer at its origin

Colorectal adenomas are responsible for the origin of most colorectal cancers (CRC). Early detection together with active intervention of colorectal adenomas plays a crucial role in the prevention of colorectal cancer. This study aimed to construct and validate a new nomogram for the forecasting of the risk of colorectal adenomas based on lifestyle risk factors that could offer potential benefits for CRC prevention. Colonoscopy reports, pathology reports, physical factors, family history, personal history of disease, diet, and lifestyle habits were collected from 1133 subjects who underwent complete colonoscopy. All subjects were divided into the training cohort (n = 792) and the validation cohort (n = 341). A nomogram predicting the risk of colorectal adenoma development was constructed using the training cohort and the C-index was calculated. The predictive accuracy and clinical applicability of the nomogram were verified in the validation cohort. The nomogram was constructed by 6 statistically significant variables selected from 18 health factors, including advanced age, male, smoking, drinking, pickles, and irregular defecation. The C-index of the training cohort was 0.778 and the C-index of the validation cohort was 0.754. The calibration curve and decision curve analysis (DCA) also confirmed that the model has good predictive ability and high profit. The nomogram constructed in this study was validated and can be applied to predicting the occurrence risk of colorectal adenoma. The model can guide the identification of patients with non-symptomatic colorectal adenomas and the recognition of high-risk individuals for whom a colonoscopy is advisable.