Is colonoscopy needed for the nonadvanced adenoma found on sigmoidoscopy? The Polyp Prevention Trial.
OBJECTIVE
The need for colonoscopy when small tubular adenomas with low-grade dysplasia are found on sigmoidoscopy is uncertain. The aim of this study was to examine the prevalence and characteristics of proximal adenomas in patients with distal adenomas.


METHODS
We studied 981 subjects with distal adenomas found on the index colonoscopy before randomization in the Polyp Prevention Trial.


RESULTS
Four hundred sixty patients (46.9%) had >/=1 distal adenoma that was pathologically advanced (villous component, high-grade dysplasia, or >/=1 cm); 21.5% (211 of 981) had any proximal adenoma; and 4.3% (42 of 981) (95% confidence interval [CI], 3.0-5.5) had an advanced proximal adenoma. A greater percentage of patients with an advanced distal adenoma (5.9%) (95% CI, 3.7-8.0) had an advanced proximal adenoma compared with those with a nonadvanced distal adenoma (2.9%) (95% CI, 1.4-4.3) (OR, 2.1; 95% CI, 1.1-4.3; P = 0.03). Not performing a colonoscopy in patients with a nonadvanced distal adenoma would have missed 36% (15 of 42) of the advanced proximal adenomas.


CONCLUSIONS
Patients with an advanced distal adenoma are twice as likely to have an advanced proximal adenoma as patients with a nonadvanced distal adenoma. However, eschewing a colonoscopy in patients with a nonadvanced distal adenoma would result in not detecting a sizeable percentage of the prevalent advanced proximal adenomas. These data support performance of a colonoscopy in patients with a nonadvanced distal adenoma. Confirmation of these results in asymptomatic subjects undergoing screening sigmoidoscopy is advisable.
Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
R E
RE
Schoen
D
D
Corle
L
L
Cranston
J L
JL
Weissfeld
P
P
Lance
R
R
Burt
F
F
Iber
M
M
Shike
J W
JW
Kikendall
M
M
Hasson
K J
KJ
Lewin
H D
HD
Appelman
E
E
Paskett
J V
JV
Selby
E
E
Lanza
A
A
Schatzkin
D000236:Adenoma / Q000175:diagnosis* / Q000473:pathology; D000328:Adult; D000368:Aged; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D003111:Colonic Polyps / Q000517:prevention & control*; D003113:Colonoscopy; D003710:Demography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012812:Sigmoidoscopy