Colon adenoma features and their impact on risk of future advanced adenomas and colorectal cancer

Table 1 Articles summarizing the risk of neoplasia based on the histology of polyps seen at baseline colonoscopy

Ref.	Sample size	Median follow-up, yr	Predictor	Primary outcome	Absolute risk of outcome (%)	RR1 [95%CI]
RCT
Laiyemo et al[11]	1905	4	Villous	ACN	9 (7-11) vs 5 (4-6)	2.3 [1.5-3.4]
Bonithon-Kopp et al[9]	552	3	HGD	ACN	9.8 vs 5.5	1.9 [1.0-3.6]
			Villous		10.3 vs. 6.8	1.7 [0.8-3.7]
Pooled analysis
Martínez et al[14]	8 studies	3.9	HGD	ACN	16.0 (13.2-18.7) vs 10.6 (9.8-11.3)	1.1 [0.8-1.4]
	9167		Villous		16.8 (15.1-18.5) vs 9.7 (9.0-10.4)	1.3 [1.1-1.5]
Meta-analysis
Saini et al[10]	5 studies	3	HGD	ACN	4% risk difference (0-8)	1.8 [1.1-3.2]
			Villous		2% risk difference (-1 to 4)	1.3 [1.0-1.7]
Prospective
Bertario et al[15]	1086	10.5	HGD	CRC	2.8 SIR (0.3-10.2) vs 0.52	Not available
			Tubulovillous Villous	Any adenoma	Not available	1.3 [1.0-1.6]
						1.8 [1.2-2.6]
2Lieberman et al[12]	1193	5.5	No adenomas	ACN	2.4	Ref
			HGD		17	6.8 [2.6-18.1]
			Villous		16	6.1 [2.5-14.7]
Chung et al[8]	3808	4.5	Villous	ACN	Not available	1.5 [0.7- 3.0]
Registry
Van Heijningen et al[13]	2990	2	HGD	AA	13	1.2 [0.8-1.8]
			Villous		8	2.0 [1.2-3.2]
			HGD	ACN	11	Not available
			Villous		17

¹Relative risk compared to patients adenomas without the predictor characteristics. Adenomas with villous compared to those without adenomas with villous features (as opposed to those without any adenomas).

²Relative risk compared to those with no neoplasia. ACN: Advanced colonic neoplasia (includes advanced adenomas and colorectal cancer); AA: Advanced adenomas; CRC: Colorectal cancer; HGD: High grade dysplasia; RCT: Randomized control trial.