Adenoma incidence decreases under the effect of polypectomy

Table 1 Outcomes of first four colonoscopies

Outcomes	Mean	SD
Index colonoscopy: 156 patients studied
Adenomas	1.68	1.01
Tubular adenomas	1.49	1.13
Tubulo-villous/villous adenomas	0.14/0.05	0.35/0.22
Size of the larger adenoma (mm)	15.51	10.36
Adenomas in the left colon/remaining colon	1.34/0.35	0.93/0.69
Second colonoscopy: 156 patients studied (41.6 ± 21.0 mo since the first)
Adenomas	0.54	0.86
Tubular adenomas	0.51	0.85
Tubulo-villous/villous adenomas	0.02/0.01	0.14/0.11
Size of the larger adenoma (mm)	8.02	7.39
Adenomas in the left colon/remaining colon	0.36/0.17	0.67/0.49
Third colonoscopy: 156 patients studied ( 83.7 ± 27.7 mo since the first)
Adenomas	0.47	0.92
Tubular adenomas	0.46	0.92
Tubulo-villous/villous adenomas	0.02/0.0	0.18/0.0
Size of the larger adenoma (mm)	6.19	4.22
Adenomas in the left colon/remaining colon	0.21/0.26	0.47/0.71
Fourth colonoscopy: 44 patients studied (116.9 ± 34.1 mo since the first)
Adenomas	0.32	0.74
Tubular adenomas	0.32	0.74
Tubulo-villous/villous adenomas	0.0/0.0	0.0/0.0
Size of the larger adenoma (mm)	5.78	1.92
Adenomas in the left colon/remaining colon	0.16/0.16	0.43/0.48

Table 2 Correlation between baseline adenoma characteristics and presence of adenomas in the second colonoscopy

Index colonoscopy	Second colonoscopy		χ2test
	0 adenomas (n)	≥1 adenoma (n)
> 1 adenoma	39	28	P = 0.24
≥ 3 adenomas	14	10	P = 0.57
≥ 1 TV adenoma	8	14	P = 0.004
≥ 1 villous adenoma	5	3	P = 0.95
≥ 1 TV or V adenoma	13	17	P = 0.01
≥ 1 adenoma > 1 cm	67	42	P = 0.43

TV: Tubulo-villous; V: Villous.

Table 3 Correlation between baseline adenoma characteristics and presence of adenomas in all subsequent colonoscopies

Index colonoscopy	Subsequent colonoscopies		χ2test
	0 adenomas (n)	≥1 adenoma (n)
> 1 adenoma	31	36	P = 0.5
≥ 3 adenomas	9	15	P = 0.2
≥ 1 TV adenoma	7	15	P = 0.08
≥ 1 villous adenoma	4	4	P = 0.97
≥ 1 TV or V adenoma	11	19	P = 0.12
≥ 1 adenoma > 1 cm	53	56	P = 0.78

TV: Tubulo-villous; V: Villous.