Colonoscopic screening of average-risk women for colorectal neoplasia.
BACKGROUND
Veterans Affairs (VA) Cooperative Study 380 showed that some advanced colorectal neoplasias (i.e., adenomas at least 1 cm in diameter, villous adenomas, adenomas with high-grade dysplasia, or cancer) in men would be missed with the use of flexible sigmoidoscopy but detected by colonoscopy. In a tandem study, we examined the yield of screening colonoscopy in women.


METHODS
To determine the prevalence and location of advanced neoplasia, we offered colonoscopy to consecutive asymptomatic women referred for colon-cancer screening. The diagnostic yield of flexible sigmoidoscopy was calculated by estimating the proportion of patients with advanced neoplasia whose lesions would have been identified if they had undergone flexible sigmoidoscopy alone. Lesions were considered detectable by flexible sigmoidoscopy if they were in the distal colon or if they were in the proximal colon in patients who had concurrent small adenomas in the distal colon, a finding that would have led to colonoscopy. The results were compared with the results from VA Cooperative Study 380 for age-matched men and women with negative fecal occult-blood tests and no family history of colon cancer.


RESULTS
Colonoscopy was complete in 1463 women, 230 of whom (15.7 percent) had a family history of colon cancer. Colonoscopy revealed advanced neoplasia in 72 women (4.9 percent). If flexible sigmoidoscopy alone had been performed, advanced neoplasia would have been detected in 1.7 percent of these women (25 of 1463) and missed in 3.2 percent (47 of 1463). Only 35.2 percent of women with advanced neoplasia would have had their lesions identified if they had undergone flexible sigmoidoscopy alone, as compared with 66.3 percent of matched men from VA Cooperative Study 380 (P<0.001).


CONCLUSIONS
Colonoscopy may be the preferred method of screening for colorectal cancer in women.
Schoenfeld
Philip
P
Division of Gastroenterology, University of Michigan School of Medicine and Veterans Affairs Center for Excellence in Health Services Research, Ann Arbor 48105, USA. pschoenf@umich.edu
Cash
Brooks
B
Flood
Andrew
A
Dobhan
Richard
R
Eastone
John
J
Coyle
Walter
W
Kikendall
James W
JW
Kim
Hyungjin Myra
HM
Weiss
David G
DG
Emory
Theresa
T
Schatzkin
Arthur
A
Lieberman
David
D
D000236:Adenoma / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics; D000328:Adult; D000368:Aged; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009780:Occult Blood; D015995:Prevalence; D012307:Risk Factors; D017678:Sex Distribution; D012737:Sex Factors; D012812:Sigmoidoscopy