Robert E. Schoen, MD MPH
Associate Professor of Medicine and Epidemiology
Division of Gastroenterology
University of Pittsburgh
Organizing Colorectal Cancer Screening
Lifetime Risk of CRC (%)
All Races 5.95, 5.63 2.43, 2.40
Whites 6.00, 5.64 2.45, 2.38
Blacks 4.73, 5.31 2.34, 2.65
Male, Female
LR Dx LR Death
SEER, 1996 - 98
Click for larger picture
Prevalence of Adenomatous Polyps
Diminutive or Small - 15 - 30%
Large - 3 - 5%
Cancer - 0.3 - 1%
Screening
for
Colorectal Cancer
CRC Often Diagnosed Late
U.S. CRC, By Stage, 1992 - 1997
Localized 37%
Regional 38%
Distant 20%
SEER: 1973 - 1998
Consensus Guidelines
50
Options: Annual FOBT FS q 5 yrs FOBT + FS DCBE q 5-10 yr Colon q 10 yr
+
TCE: Colonoscopy or DCBE + FS
Gastro. 1997:112;594
Minnesota FOBT Trial: 18 Yr Follow Up
Annual Biennial Control
15,570 15,587 15,394
240,325 240,163 237,420
.67 (.51-.83) .79 (.62-.97) 1.0
Mandel, JNCI 1999;91:434
# enrolled
PYO
CRC Mortality Ratio*
*Overall mortality not changed
Decreased Incidence of CRC in the Minnesota FOBT Study
Mandel JS et al. N Engl J Med 2000:343:1603-7
17% in biennial
20% in annual
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Highlights of Trials of Non-Rehydrated FOBT
Compliance
% with positive test (initial screen)
% with positive test found to have cancer
% reduction in CRC mortality (biennial testing)
60 - 69
0.6 - 4.4
5 - 17.2
15 - 18
%
Screening Sigmoidoscopy - Efficacy
Case Control Study: Compared Rigid Sig Use in 261 pts who died of distal CRC to 868 matched age/sex) controls
8.8% of Cases Screened VS. 24.2% of Controls
OR for CRC Mortality w/ Sigmo = .41 or 59%*
* adjusted for polyp hx, fam hx, check ups• Benefits persisted 10 years• No difference in screening in 268 cases/controls with CA above rectosigmoid
Selby et al. NEJM 1992;326:653
Is Sigmoidoscopy Half a Mammogram?
Screening Colonoscopy Studies
Imperiale et al - “Lilly Cohort”
NEJM 2000; 343:162
Lieberman et al - “VA Cooperative 380”
NEJM 2000; 343:169
Success - Complications
Cecum - 97+%
Perforation - 1/5115 or 0.02%
NEJM 2000: Screening Colonoscopy Studies
VA Study: Major morbidity - 0.32% (GI bleed, MI, CVA)
VA Colonoscopy Study 380
Adenoma 37.5% Advanced Adenoma* 10.7%
Tubular 5.0% Villous 3.0% HGD 1.7%
CA 1.0%
N=3121, 97% male, mean age 63
Lieberman et al, NEJM 2000* 1 cm, Villous, HGD, CA
Lilly Cohort
Adenoma 20%Advanced Adenoma* 5.6%CA 0.6%
*Villous, HGD (not 1 cm)
N=1994, 58.9% male, mean age 60
Imperiale et al, NEJM 2000
What Does Screening Colonoscopy Detect That Sigmoidoscopy Doesn’t?
VA Study Lilly Cohort
Neoplasia 37.5% 20%
Advanced ProximalNeoplasia 4.1% 2.5%
“Missed” AdvancedProximal Neoplasia 2.1% 1.2%
Older age, males higher risk
Missed Advanced Proximal Neoplasia
VA - 52% “missed” (67/128) or 2.1%
Limit Advanced Definition to HGD or CA:
VA - 14.8% missed (12/81) or 0.4%
Incident CRC After Colonoscopy
Winawer (NPS)
Schatzkin (PPT)
Alberts (Wheat Bran)
N
1418
1905
1303
Observed (yrs)
5.9
3.05
2.91
PYO
8401
5810
3789
CRC Cases
5
14
9
Incidence/1000 PYO
0.6
2.4
2.4
Sigmoidoscopy vs. Colonoscopy
More sensitive
More invasive, safe?
Expensive
Less frequent (1/10 yr)?
Less accessible
Better satisfaction
Sensitive enough?
Safer
Less expensive
Frequency (1/5 yr)?
Accessible?
Satisfied?
Colonoscopy SigmoidoscopyVs.
Recommended
