Five-year colon surveillance after screening colonoscopy.
OBJECTIVE
Outcomes of colon surveillance after colorectal cancer screening with colonoscopy are uncertain. We conducted a prospective study to measure incidence of advanced neoplasia in patients within 5.5 years of screening colonoscopy.


METHODS
Three thousand one hundred twenty-one asymptomatic subjects, age 50 to 75 years, had screening colonoscopy between 1994 and 1997 in the Department of Veterans Affairs. One thousand one hundred seventy-one subjects with neoplasia and 501 neoplasia-free controls were assigned to colonoscopic surveillance over 5 years. Cohorts were defined by baseline findings. Relative risks for advanced neoplasia within 5.5 years were calculated. Advanced neoplasia was defined as tubular adenoma greater than > or =10 mm, adenoma with villous histology, adenoma with high-grade dysplasia, or invasive cancer.


RESULTS
Eight hundred ninety-five (76.4%) patients with neoplasia and 298 subjects (59.5%) without neoplasia at baseline had colonoscopy within 5.5 years; 2.4% of patients with no neoplasia had interval advanced neoplasia. The relative risk in patients with baseline neoplasia was 1.92 (95% CI: 0.83-4.42) with 1 or 2 tubular adenomas <10 mm, 5.01 (95% CI: 2.10-11.96) with 3 or more tubular adenomas <10 mm, 6.40 (95% CI: 2.74-14.94) with tubular adenoma > or =10 mm, 6.05 (95% CI: 2.48-14.71) for villous adenoma, and 6.87 (95% CI: 2.61-18.07) for adenoma with high-grade dysplasia.


CONCLUSIONS
There is a strong association between results of baseline screening colonoscopy and rate of serious incident lesions during 5.5 years of surveillance. Patients with 1 or 2 tubular adenomas less than 10 mm represent a low-risk group compared with other patients with colon neoplasia.
Lieberman
David A
DA
Department of Veterans Affairs Medical Center, Portland, Oregon 97239, USA. lieberma@ohsu.edu
Weiss
David G
DG
Harford
William V
WV
Ahnen
Dennis J
DJ
Provenzale
Dawn
D
Sontag
Stephen J
SJ
Schnell
Thomas G
TG
Chejfec
Gregorio
G
Campbell
Donald R
DR
Kidao
Jayashri
J
Bond
John H
JH
Nelson
Douglas B
DB
Triadafilopoulos
George
G
Ramirez
Francisco C
FC
Collins
Judith F
JF
Johnston
Tiina K
TK
McQuaid
Kenneth R
KR
Garewal
Harinder
H
Sampliner
Richard E
RE
Esquivel
Romeo
R
Robertson
Douglas
D
D000236:Adenoma / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D000368:Aged; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D018450:Disease Progression; D005500:Follow-Up Studies; D006787:Hospitals, Veterans; D006801:Humans; D015994:Incidence; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D017410:Practice Guidelines as Topic; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014481:United States / Q000453:epidemiology