Predicting three-year risk of incident colorectal precancerous conditions using non-invasive predictors and machine-learning algorithms: A multi-center retrospective study

Table 1 Baseline characteristics and incident events of study participants, median (interquartile range)/n (%)

Characteristics	Training	Internal validation	External validation	P value	Overall
n	762	761	285		1808
Incident AA	53 (7.0)	52 (6.8)	26 (9.1)	0.410	131 (7.3)
Site of incident AA				0.012
Rectum	6 (0.8)	19 (2.5)	10 (3.5)		35 (1.9)
Left colon	28 (3.7)	14 (1.8)	6 (2.1)		48 (2.7)
Right colon	19 (2.5)	19 (2.5)	10 (3.5)		48 (2.7)
Age (years)	48 (41, 54)	47 (40, 53)	51 (43, 59)	< 0.001	48 (41, 54)
Female sex	175 (23.0)	164 (21.6)	106 (37.2)	< 0.001	445 (24.6)
DBP (mmHg)	74 (66, 82)	73 (66, 82)	76 (69, 84)	0.020	74 (66, 82)
STK1p (pmol/L)	0.16 (0.10, 0.24)	0.16 (0.10, 0.23)	0.33 (0.17, 0.72)	< 0.001	0.17 (0.11, 0.26)
FIT positive	213 (27.95)	216 (28.38)	77 (27.0)	0.908	506 (28.0)
CYFRA21-1 (μg/L)	2.00 (1.42, 2.70)	1.92 (1.44, 2.80)	1.26 (0.95, 1.42)	< 0.001	1.83 (1.26, 2.60)
CA19-9 (kU/L)	6.90 (3.62, 11.08)	6.72 (3.75, 11.27)	6.69 (3.50, 11.53)	0.959	6.77 (3.62, 11.24)

Advanced adenoma (including adenoma ≥ 10 mm, with villous components, or exhibiting high-grade dysplasia) diagnosis based on the National Comprehensive Cancer Network guideline. AA: Advanced adenoma; CA19-9: Carbohydrate antigen 19-9; CYFRA21-1: Cytokeratin 19 fragment; DBP: Diastolic blood pressure; FIT: Fecal immunochemical test; STK1p: Serum thymidine kinase 1 protein.