Organizing Colorectal Cancer Screening

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

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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.