Adverse effects of colorectal cancer screening with fecal occult blood test: a population-based organized program

Results – serious adverse effects

Adverse effects (AE) of colorectal cancer (CRC) screening have not yet been assessed as thoroughly as those of mammography screening. Aim: to assess 1) AE of a CRC screening program with guaiac-based fecal occult blood test (gFOBT) and 2) the optimal method for their routine detection. Methods: Identification of AE of the organized CRC screening program with biennial gFOBT in progress in the Haut-Rhin since 2003 through 1) voluntary reporting by gastroenterologists, 2) AE report forms by general practitioners (GPs), 3) retrospective questionnaire mailed to GPs and 4) retrospective questionnaire mailed to persons explored by colonoscopy. Results: 114,137 persons completed 173,352 gFOBTs in 4 years. 2194 of 3810 colonoscopic procedures displayed no neoplasia that is a 57.6% false positive rate. Overall, 17 (4.5/1000) serious AE were recorded: 4 (1.0/1000) perforations, 8 (2.1/1000) bleeding, 3 postpolypectomy syndromes and 2 major anxiety attacks. They resulted in 15 hospitalizations, 6 colonoscopic procedures, 5 surgical operations and 3 blood transfusions. 10 (58.8%) were voluntarily reported by gastroenterologists, 8 (47.1%) were notified by GPs answering the questionnaire and 1 through the AE report form and 7 (41.2%) by patients via the questionnaire. 4 undue surgical operations were recorded, 1 due to an erroneous CT diagnosis of CRC and 3 to an erroneous pathologic overdiagnosis of T1 malignant polyp. 50 colonoscopic procedures were repeated within 6 months without justification. 2288 (61.6%) persons explored by colonoscopy answered the questionnaire and reported 252 (11.1%) minor AE such as abdominal pain after the procedure (50 cases), change in bowel habits (59 cases), bloating (62 cases), nausea/vomiting (16 cases) and fever (11 cases). 494 (21.6%) reported stress when receiving the mail announcing the positive result, 397 (17.4%) judged the bowel preparation awful and 86 (3.8%) experienced pain during colonoscopy. 16 complained about the waiting period before the colonoscopy appointment. 305 GPs (51.4%) answered the questionnaire concerning 1877 patients and notified 80 AE (4.3%). Only 6 AE were reported with the AE report forms. Conclusion: Provided they are actively sought, AE of CRC screening with gFOBT are more frequent than previously reported. Though most of them are minor, the invited population should be informed. The detection of AE must rely on several sources of information. Voluntary reporting by gastroenterologists detects only the half of serious AE. The patient's questionnaire is the most sensitive method for the detection of minor AE and should be routinely proposed to persons screened by colonoscopy.

Aimto assess 1) AE of a CRC screening program with guaiac-based fecal occult blood

test (gFOBT) and 2) the optimal method for their routine detection

- 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

- identification of AE from September 2003 to July 2007 through

1) voluntary reporting by gastroenterologists, 2) AE report forms by general practitioners (GPs), 3) retrospective questionnaire mailed to GPs and 4) retrospective questionnaire mailed to persons explored by colonoscopy

Conclusions

- Adverse Effects (AE) of CRC screening with gFOBT are more

frequent than previously reported, provided they are actively sought

- Though most of them are minor, the invited population should be

informed

- The detection of AE must rely on several sources of information:

. Voluntary reporting by gastroenterologists detects only the

half of serious AE.

. The patient's questionnaire is the most sensitive method for

the detection of minor AE and should be routinely proposed to

persons screened by colonoscopy.

Digestive Disease Week, San Diego, 21 May 2008

Background

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

Abstract Results

Methods

Overall results

Joël LACROUTE, Isabelle GENDRE, Jean Marc BOYAVAL, Philippe PERRIN, Bernard DENIS

- Adverse effects (AE) of colorectal cancer (CRC) screening have not yet been assessed as thoroughly as those of mammography screening

. Funen trial ? (Kronborg, Lancet 1996)

. Burgundy trial 0 serious AE /1691 colonoscopic procedures (Faivre, Gy 2004)

. Nottingham trial 0.5% serious AE (Hardcastle, Lancet 1996)

. Haut-Rhin pilot program 0.2% serious AE (Denis, Gut 2007)

- When actively sought, AE are more frequent than usually reported (Zubarik GIE 1999, Bini GIE 2003, Denis GCB 2004)

- 114,137 persons completed 173,352 gFOBTs in 4 years- 4701 gFOBT positive- 3810 colonoscopic procedures registered- 2194 colonoscopic procedures displayed no neoplasia that is a

57.6% false positive rate

100,0%

62,5%

51,0%

0,6%

0% 20% 40% 60% 80% 100%

Adverse effects number rate literature

serious 17 0.45% 0.4 – 0.5% 1

minor 329 10.7% 13.7 – 15% 2

1. Dafnis GIE 2001, Hardcastle Lancet 1996, 2. Zubarik GIE 1999, Bini GIE 2003

Serious adverse effects number rate literature perforation 4 0.1% 0.016% - 0.13% delayed bleeding 8 0.2% 0.07% - 1.6%post-polypectomy Sd 3 0.08% -deep vein thrombosis 2 0.05% -

Results – minor adverse effects

They resulted in - no death- 15 hospitalizations (130 days) - 8 colonoscopic procedures - 5 surgical operations- 3 blood transfusions

Minor adverse effects number rate

Abdominal pain during procedure 94 3.1%

Abdominal pain after procedure 50 1.6%

Bloating 63 2.1%

Change in bowel habits 60 2.0%

Minor bleeding 27 0.9%

Nausea/vomiting 15 0.5%

Anxiety 60 2.0%

Fever 11 0.4%

Vasovagal episode 2 0.07%

Positive FOBT result very distressing 502 21.6%

Bowel prep very distressing 413 17.8%

Response rates

AE form

GPs’ questionnaire

Patients’ questionnaire

Gastroenterologist report

5,5%

47,1%

76,3%

41,2%

22,2%

52,9%

1,5%

5,9%

0% 20% 40% 60% 80%

serious AE

minor AE

AE form

GPs’ questionnaire

Patients’ questionnaire

Gastroenterologist report

Yield of information sources