Gastroenterology

Gastroenterology

Volume 144, Issue 5, May 2013, Pages 918-925
Gastroenterology

Original Research
Full Report: Clinical—Alimentary Tract
A Population-based Comparison of Immunochemical Fecal Occult Blood Tests for Colorectal Cancer Screening

https://doi.org/10.1053/j.gastro.2013.01.042Get rights and content

Background & Aims

Quantitative fecal immunochemical tests (FITs) identify individuals with colorectal cancer with greater levels of accuracy than guaiac tests. We compared the performances of 2 FITs in a population undergoing screening for colorectal cancer.

Methods

We collected fecal samples from 19,797 individuals in France (age, 50−74 y) who participated in a colorectal cancer screening program, from June 2009 through May 2011. Samples were analyzed using the Magstream (Fujirebio Inc, Tokyo, Japan) and OC Sensor (Eiken Chemical Co, Tokyo, Japan) (2 samples each) FITs, as well as the Hemoccult II guaiac test (SKD, Villepinte, France) (3 samples each). Colonoscopies were performed for patients with positive results from all 3 tests. The cut-off values for levels of hemoglobin in buffer and stools were 55 ng/mL and 180 μg/g for the Magstream and 150 ng/mL and 30 μg/g for the OC Sensor, respectively. Results from the FITs were compared with those from the guaiac test for cut-off values for stool samples, positivity rates, and the receiver operating characteristic curve values. The numbers needed to screen and the numbers needed to scope to detect an advanced neoplasia (cancer, adenoma ≥10 mm, or high-grade dysplasia) were calculated.

Results

A positive test result was found in 1224 participants (6.2%); 1075 (87.8%) underwent a colonoscopy examination. Of these, 334 were found to have advanced neoplasia. Considering the cut-off values associated with the positivity rate of Hemoccult II (1.6%), the numbers needed to screen were 239 for Hemoccult II, 166 for a 1-sample Magstream FIT, and 129 for a 1-sample OC Sensor FIT; the numbers needed to scope were 3.3, 2.3, and 1.8, respectively. For the same false-positive rate as Hemoccult II (0.98%), the true-positive rates for Magstream and OC Sensor FITs were 0.65% and 0.90% respectively, compared with 0.42% for Hemoccult II. The OC Sensor FIT had a greater area under the receiver operating characteristic curve value than the Magstream FIT.

Conclusions

Based on results from a large, population-based study, the OC Sensor FIT identifies patients with colorectal cancer with greater accuracy than the Magstream FIT. ClinicalTrials.gov number: NCT01251666.

Section snippets

Study Population and Design

Between June 2009 and May 2011, there were 19,797 residents of 2 French counties (Allier and Cher) who fulfilled inclusion criteria for the ongoing biennial organized screening program (aged 50–74 y, no digestive symptoms or personal or first-degree relatives with a history of colorectal cancer or advanced adenoma, no colonoscopy in the past 5 years) who were enrolled in a study comparing Magstream and OC Sensor FITs. Participation in the study was suggested at the time of centralized

Results

Figure 1 presents the study flow chart. Among the 1224 subjects who were positive for at least one of the tests, an analyzable colonoscopy was performed for 1075 subjects (87.8%), with a mean time interval between a positive screening and colonoscopy of 71 days (median, 56 days). No colonoscopy complications were reported. A total of 334 participants were diagnosed with advanced neoplasia at colonoscopy.

In Table 1, 16.5% of participants underwent colorectal cancer screening for the first time.

Discussion

Our results, directly comparing the performances of the 2 FITs in an average-risk population, strongly suggest that the OC Sensor outperforms Magstream for both the detection of invasive cancers alone or advanced neoplasias as a whole; the 2 tests provide a substantial improvement in cancer screening in comparison with Hemoccult II. Strikingly, for the same number of positive results, 1-sample OC Sensor nearly doubled the number of advanced neoplasias detected compared with the 3-sample guaiac

Acknowledgments

The authors are grateful to all subjects who agreed to join the study, to the general practitioners who included the patients, to the endoscopists who performed the colonoscopies, to the members of the 2 regional associations in charge of colorectal cancer screening, ADOC18 and ABIDEC, to the Institut InterRégional pour la Santé laboratory, and to the research team Cancers and Preventions who were involved in the study.

References (27)

  • J.E. Allison et al.

    A comparison of fecal occult-blood tests for colorectal-cancer screening

    N Engl J Med

    (1996)
  • L. Hol et al.

    Screening for colorectal cancer: randomised trial comparing guaiac-based and immunochemical faecal occult blood testing and flexible sigmoidoscopy

    Gut

    (2010)
  • L. Guittet et al.

    Performance of immunochemical faecal occult blood test in colorectal cancer screening in average-risk population according to positivity threshold and number of samples

    Int J Cancer

    (2009)
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    Conflicts of interest The authors disclose no conflicts.

    Funding The study was funded by the French National Institute for Cancer (Institut National du Cancer), and the French National League against Cancer (Ligue Nationale Contre le Cancer); the automat analyzers were provided on loan by Eiken (OC Sensor Diana automat) and Fujirebio (Magstream HT automat) manufacturers. The sponsors and manufacturers had no role in the study design or data analysis.

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