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Clinical Trial
. 2008 Oct 7;149(7):441-50, W81.
doi: 10.7326/0003-4819-149-7-200810070-00004.

Stool DNA and occult blood testing for screen detection of colorectal neoplasia

David A Ahlquist  1 , Daniel J Sargent, Charles L Loprinzi, Theodore R Levin, Douglas K Rex, Dennis J Ahnen, Kandice Knigge, M Peter Lance, Lawrence J Burgart, Stanley R Hamilton, James E Allison, Michael J Lawson, Mary E Devens, Jonathan J Harrington, Shauna L Hillman
Affiliations
Clinical Trial

Stool DNA and occult blood testing for screen detection of colorectal neoplasia

David A Ahlquist et al. Ann Intern Med. .

Abstract

Background: Stool DNA testing is a new approach to colorectal cancer detection. Few data are available from the screening setting.

Objective: To compare stool DNA and fecal blood testing for detection of screen-relevant neoplasia (curable-stage cancer, high-grade dysplasia, or adenomas >1 cm).

Design: Blinded, multicenter, cross-sectional study.

Setting: Communities surrounding 22 participating academic and regional health care systems in the United States.

Participants: 4482 average-risk adults.

Measurements: Fecal blood and DNA markers. Participants collected 3 stools, smeared fecal blood test cards and used same-day shipment to a central facility. Fecal blood cards (Hemoccult and HemoccultSensa, Beckman Coulter, Fullerton, California) were tested on 3 stools and DNA assays on 1 stool per patient. Stool DNA test 1 (SDT-1) was a precommercial 23-marker assay, and a novel test (SDT-2) targeted 3 broadly informative markers. The criterion standard was colonoscopy.

Results: Sensitivity for screen-relevant neoplasms was 20% by SDT-1, 11% by Hemoccult (P = 0.020), 21% by HemoccultSensa (P = 0.80); sensitivity for cancer plus high-grade dysplasia did not differ among tests. Specificity was 96% by SDT-1, compared with 98% by Hemoccult (P < 0.001) and 97% by HemoccultSensa (P = 0.20). Stool DNA test 2 detected 46% of screen-relevant neoplasms, compared with 16% by Hemoccult (P < 0.001) and 24% by HemoccultSensa (P < 0.001). Stool DNA test 2 detected 46% of adenomas 1 cm or larger, compared with 10% by Hemoccult (P < 0.001) and 17% by HemoccultSensa (P < 0.001). Among colonoscopically normal patients, the positivity rate was 16% with SDT-2, compared with 4% with Hemoccult (P = 0.010) and 5% with HemoccultSensa (P = 0.030).

Limitations: Stool DNA test 2 was not performed on all subsets of patients without screen-relevant neoplasms. Stools were collected without preservative, which reduced detection of some DNA markers.

Conclusion: Stool DNA test 1 provides no improvement over HemoccultSensa for detection of screen-relevant neoplasms. Stool DNA test 2 detects significantly more neoplasms than does Hemoccult or HemoccultSensa, but with more positive results in colonoscopically normal patients. Higher sensitivity of SDT-2 was particularly apparent for adenomas.

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Conflict of interest statement

Potential Financial Conflicts of Interest: Consultancies: D.J. Ahnen (EXACT Sciences), J.E. Allison (Fujirebio, Quidel). Stock ownership or options (other than mutual funds): J.E. Allison (IntelligeneScan). Grants received: T.R. Levin (EXACT Sciences), M.P. Lance (National Institutes of Health), M.J. Lawson (EXACT Sciences). The Mayo Clinic is a minor equity investor in EXACT Sciences.

Figures

Figure 1
Figure 1. Study flow diagram
Figure 2
Figure 2. Stool DNA versus occult blood testing for detection of screen-relevant neoplasia (curable-stage colorectal cancer, high-grade dysplasia, and adenomas ≥1 cm) (n = 142)
Sensitivity is plotted for Hemoccult and HemoccultSensa with 1, 2, and 3 stools per patient and with stool DNA test 2 (SDT-2) on a single stool per patient. Vertical lines represent 95% CIs. *P < 0.001 versus Hemoccult or HemoccultSensa.
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References

    1. Jemal A, Siegel R, Ward E, Murray T, Xu J, Thun MJ. Cancer statistics, 2007. CA Cancer J Clin. 2007;57:43–66. - PubMed
    1. Mandel JS, Bond JH, Church TR, Snover DC, Bradley GM, Schuman LM, et al. Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study. N Engl J Med. 1993;328:1365–71. - PubMed
    1. Hardcastle JD, Chamberlain JO, Robinson MH, Moss SM, Amar SS, Balfour TW, et al. Randomised controlled trial of faecal-occult-blood screening for colorectal cancer. Lancet. 1996;348:1472–7. - PubMed
    1. Kronborg O, Jørgensen OD, Fenger C, Rasmussen M. Randomized study of biennial screening with a faecal occult blood test: results after nine screening rounds. Scand J Gastroenterol. 2004;39:846–51. - PubMed
    1. Winawer SJ, Flehinger BJ, Schottenfeld D, Miller DG. Screening for colorectal cancer with fecal occult blood testing and sigmoidoscopy. J Natl Cancer Inst. 1993;85:1311–8. - PubMed