Small early tubular adenomas and mixed colonic polyps found on screening flexible sigmoidoscopy do not predict proximal neoplasia in males.
OBJECTIVE
Distal colonic adenomas found on flexible sigmoidoscopy are associated with proximal neoplasias, thus requiring a complete colonoscopic examination, but data regarding the association of distal mixed polyps with proximal neoplasia are lacking. We conducted this study to elucidate the significance of distal mixed colonic polyps in predicting proximal neoplasia.


METHODS
We retrospectively analyzed data from patients who underwent a flexible sigmoidoscopic examination for colorectal cancer screening and a follow-up colonoscopic examination because of distal colonic polyps. Distal index polyps were classified by a pathologist as early tubular adenoma (ETA), serrated, or true mixed categories. Index polyps also were immunostained with a monoclonal antibody, Adnab-9, a marker for the colorectal adenoma carcinoma sequence.


RESULTS
In 636 patients with distal index polyps, 6% were malignant, 55% were adenomas, 13% were ETAs, 6% were serrated, 4% were true mixed, and 17% were hyperplastic. Compared with distal hyperplastic index polyps, distal malignant polyps (P = 0.0006) and adenomas (P = 0.001) were associated with a significantly increased number of synchronous proximal neoplasia, but the small distal mixed, serrated, or ETA did not predict the increased incidence of proximal neoplasia. Large distal polyps of each category were significantly associated with an increased number of synchronous proximal neoplasias. In support of these findings, immunostaining of distal polyps with Adnab-9 showed predictability for proximal neoplasia only in the adenoma category (P < 0.05).


CONCLUSIONS
Small ETAs, serrated, or mixed polyps found on flexible sigmoidoscopic examination do not increase the probability of synchronous proximal neoplasia.
Ullah
Nadeem
N
Wayne State University School of Medicine, Detroit, Michigan, USA.
Qureshi
Kashif
K
Hatfield
James
J
Sochacki
Paula
P
David
Doina
D
Albataineh
Hassan
H
Mejia
Luis
L
Kenkre
Chaya
C
Lawson
Michael
M
Tobi
Martin
M
D018256:Adenomatous Polyps / Q000453:epidemiology / Q000473:pathology*; D000368:Aged; D001707:Biopsy, Needle; D015331:Cohort Studies; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000473:pathology*; D003111:Colonic Polyps / Q000453:epidemiology / Q000473:pathology*; D016001:Confidence Intervals; D005260:Female; D005336:Fiber Optic Technology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009367:Neoplasm Staging; D016017:Odds Ratio; D011230:Precancerous Conditions / Q000473:pathology*; D011237:Predictive Value of Tests; D011336:Probability; D018570:Risk Assessment; D017678:Sex Distribution; D020694:Sigmoidoscopes; D012812:Sigmoidoscopy / Q000379:methods