Development and validation of a risk score for advanced colorectal adenoma recurrence after endoscopic resection

Table 1 Baseline characteristics of patients

Variable	All patients (n = 843)
Age (yr)	58 (52-67)
Gender
Male	522 (61.9)
Female	321 (38.1)
BMI	25 (22-28)
ASA score	2 (1-3)
Lesion size (mm)	16 (12-23)
Number of adenomas	2.5 (1-3)
Number of ACAs	1.5 (1-2)
Morphology1 pedunculated (Paris 1p)	473 (40.9)
Sessile (Paris 1s)	458 (39.6)
Nonpolypoid (Paris 0-IIa, 0-IIb, 0-IIc)	224 (19.5)
Location1
Right side of the colon	431 (37.3)
Left side of the colon	724 (62.7)
Type of resection1	937 (81.1)
En bloc piecemeal	218 (18.9)
Histology1
Tubular	436 (37.7)
Tubulo-villous	632 (54.7)
Villous	87 (7.6)
Hystologic grade of dysplasia1
Low grade	878 (76.1)
High grade	277 (23.9)

¹Percentages computed on the total number of ACAs (n = 1155). Continuous variables are expressed as median (interquartile range) whereas categorical ones as absolute number (percentage). BMI: Body mass index; ASA: American Society of Anaesthesiology; ACA: Advanced colorectal adenoma.

Table 2 Univariate analysis of risk factors for 3-year recurrence

Variables	Odds ratio (95%CI)	P-value
Age (reference ≤ 55 yr)	1.31 (0.88-1.44)	0.14
Gender (reference female)	1.47 (0.87-1.88)	0.09
Size (reference ≤ 15 mm)	2.84 (1.75-4.19)	< 0.001
Number of ACAs (reference 1)	2.69 (1.88-4.53)	< 0.001
Morphology (reference pedunculated)		0.01
Sessile	1.96 (1.21-2.43)
Nonpolypoid	2.43 (1.14-3.26)
Location (reference right side colon)	1.18 (0.76-1.35)	0.57
Type of resection (reference en bloc)	8.49 (3.87-11.47)	< 0.001
Histology (reference Tubular)		0.07
Tubulo-Villous	1.49 (0.47-5.18)
Villous	1.73 (0.68-4.45)
Grade of dysplasia (reference low-grade)	3.25 (1.23-5.60)	< 0.001

ACA: Advanced colorectal adenoma.

Table 3 Results of multivariate stepwise backward regression analysis of prognostic factors for 3-year recurrence

Variable	Odds ratio (95%CI)	Regression coefficient	Score points1	P-value
Grade of dysplasia
Low-grade	1		-
High-grade	4.25 (2.11-7.5)	1.93	4	< 0.001
Size
≤ 15 mm	1		-
> 15 mm	3.96 (1.87-7.55)	1.61	3	< 0.001
Number of ACAs
1	1		-
> 1	3.22 (2.19-5.39)	1.21	2	< 0.001

¹The regression coefficients were multiplied by 2 and rounded in order to facilitate the calculation of the score. ACA: Advanced colorectal adenoma.