Organized colorectal cancer screening program with FOBT: participation and diagnostic yield deteriorate with time

Results – yield

AimTo assess the short term outcomes of the 2nd round of a biennial

gFOBT CRC screening program

- Setting: a French administrative district: Haut-Rhin . 0.71 million inhabitants. All residents aged 50-74 invited since 2003 to

participate in an organized CRC screening program with biennial gFOBT (Hemoccult II)

Denis B et al Gut 2007;56:1579-84 - Comparison of the outcomes of the 1st and 2nd rounds (R1 and R2) of the program

Conclusions- Participation and diagnostic yield deteriorated with time in our

organized population-based gFOBT CRC screening program.

- Despite an increasing involvement of GPs, more than a quarter of

eligible people did not repeat screening in the 2nd round.

- This deterioration was not observed in previous RCTs on gFOBT

screening and may question the reproducibility of their effectiveness

on the reduction of CRC mortality in the real world.

Digestive Disease Week, Chicago, 2 June 2009

Background

Association pour le Dépistage du Cancer colorectal en Alsace (ADECA Alsace), Colmar, FRANCE

Abstract Results - participation

Methods

Results – GPs’ involvement

Bernard DENIS, Isabelle GENDRE, Jean François EBELIN, Pierre SAFRA, Philippe WEBER, François VODINH, Maurice MARIOTTE, Jean Yves VOGEL, Philippe PERRIN

Results – yield

Funding- Assurance Maladie- Conseil Général du Haut-Rhin- DRASS

Conflict of interest : none

Guaiac based fecal occult blood test (gFOBT) is the only screening tool with high-quality evidence obtained from randomised controlled trials (RCTs) demonstrating its efficacy to reduce colorectal cancer (CRC) mortality. However, it has some drawbacks, one is the requirement for frequent testing, which may limit compliance and thereby effectiveness. Aim: to assess the short term outcomes of the 2nd round of a biennial gFOBT CRC screening program.Methods: Comparison of the outcomes of the 1st and 2nd rounds (R1 and R2) of the organized CRC screening program with Hemoccult II implemented in the Haut-Rhin, a French administrative area, since 2003 (Denis B et al Gut 2007;56:1579-84). Results: Main outcomes are presented in the table. The crude participation rate decreased from 49.0% to 45.0%. 57.0% of excluded people had a recent < 5 years colonoscopy and 37.5% were at increased CRC risk. 28.4% of people who had participated in R1 did not participate in R2 and conversely, 25.4% of people who participated in R2 had not participated in R1. 83.9% of the completed gFOBTs were provided by general practitioners (GPs) and 12.1% by direct mailing in R2 and respectively 78.6% and 15.5% in R1 (p<0.001). 93.7% of people who received a gFOBT from their GP actually completed it in R2 vs. 81.6% in R1 (p<0.001). The rate of ≥ 10 mm adenomas did not differ between R1 (32.9%) and R2 (30.5%). The positive predictive value for advanced neoplasia was significantly lower in R2 (28.3%, p=0.04) and in people who had a previous negative gFOBT result (27.2%, p=0.01) than in R1 (31.1%). The rate of invasive cancers limited to the colorectal wall was not different between R2 (59.3%) and R1 (69.4%).Conclusion: Participation and diagnostic yield deteriorated with time in our organized population-based gFOBT CRC screening program. Despite an increasing involvement of GPs, more than a quarter of eligible people did not repeat screening in the 2nd round. This deterioration was not observed in previous RCTs on gFOBT screening and may question the reproducibility of their effectiveness on the reduction of CRC mortality in the real world.

Haut-Rhin

Round 1 Round 2 pPopulation n 186200 194190 -Excluded n (%) 19271 (10.3) 28123 (14.5) < 0.001Screened n (%) 90602 (54.3) 86274 (52.0) < 0.001Positive n (%) 3101 (3.4) 2179 (2.5) < 0.001Colonoscopies n (%) 2790 (90.0) 1928 (88.5) NSNormal colonoscopies n (%) 1601 (57.3) 1131 (58.7) NSCancers n [/ 1000 screened] 206 [2.3] 119 [1.4] < 0.001Cancers stage I n (%) 93 (45.2)45 (38.1)NSAdenoma ≥ 10mm n [/ 1000 screened] 543 [6.0] 354 [4.1] < 0.001

54,3%

10,3%

49,0% 52,0%

14,5%

45,0%

crudeparticipation

exclusions adjustedparticipation

4000p < 0.001

0,6%

3,4%

12,1%

83,9%

1,0%

5,4%

15,5%

78,1%

occupational medphysician

health check-up

direct mailing

GP

R1

R2

82%

94%

% FOBTperformed / given

by GP

- 28.4% of people who had participated in R1 did not participate in R2 - 25.4% of people who participated in R2 had not participated in R1 -The rate of colonoscopies performed was not significantly different between R1 (90.0%) and R2 (88.5%)

3,4%

10,6%

31,1% 28,3%

7,6%2,5%

positivity rate PPV cancer PPV advancedneoplasia

R1 R2 pNormal colonoscopies n (%) 1601 (57.3) 1131 (58.7) NSCancers n [/1000 screened] 206 [2.3] 119 [1.4] < 0.001Adenoma ≥ 10mm n [/ 1000 screened] 543 [6.0] 354 [4.1] < 0.001Advanced neoplasia n [/ 1000 screened] 850 [9.4] 557 [6.4] < 0.001

- The positive predictive value for advanced neoplasia was significantly lower in R2 (28.3%, p=0.04) and in people who had a previous negative gFOBT result (27.2%, p=0.01) than in R1 (31.1%)- Complications : 2 perforations (1.0 / 1000) and 4 bleeding (2.1 / 1000)

I -

32,4%

I I -

17,4%

I I I -

16,3%

IV -

5,9%0 -

28,2%

I -

31,0%I I -

17,2%

I I I -

22,8%

IV -

10,3% 0 -

18,6%- RCTs have demonstrated the efficacy of screening with guaiac based fecal occult blood test (gFOBT) on both CRC mortality and incidence. - The European trials using a biennial non-rehydrated gFOBT showed reductions of 15% to 18% in deaths from CRC after screening. - Participation and diagnostic yield of the first round of RCTs on gFOBT screening are reproducible in the real-world at an acceptable cost through an organised population-based program involving GPs (Denis B et al Gut 2007;56:1579-84).- Do these results last with time? One may fear that adherence with frequent repeat testing every other year deteriorates with time in the real-world.

p < 0.001

p = 0.001

p = 0.04

Results – Cancer stages

R1 R2