Journal of the National Cancer Institute Advance Access originally published online on August 21, 2009
JNCI Journal of the National Cancer Institute 2009 101(18):1244-1258; doi:10.1093/jnci/djp265
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© The Author 2009. Published by Oxford University Press.
ARTICLES |
Analysis of Fecal DNA Methylation to Detect Gastrointestinal Neoplasia
Affiliations of authors: Department of Gastroenterological Surgery and Surgical Oncology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama City, Okayama, Japan (TN, NT, D-SS, HS, TU, YN, NM); Division of Gastroenterology, Department of Internal Medicine, Charles A Sammons Cancer Center and Baylor Research Institute, Baylor University Medical Center, Dallas, TX (TN, MK, NN, CRB, AG); Department of Statistics, Radiation Effects Research Foundation, Hiroshima City, Hiroshima, Japan (HMC); Department of Gastroenterology and Hepatology, Kyoto University Graduate School of Medicine, Kyoto City, Kyoto, Japan (NN)
Correspondence to: Takeshi Nagasaka, MD, Department of Gastroenterological Surgery and Surgical Oncology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama City, Okayama 700-8558, Japan (e-mail: takeshin{at}cc.okayama-u.ac.jp).
Background: The development of noninvasive screening tests is important to reduce mortality from gastrointestinal neoplasia. We sought to develop such a test by analysis of DNA methylation from exfoliated cancer cells in feces.
Methods: We first analyzed methylation of the RASSF2 and SFRP2 gene promoters from 788 primary gastric and colorectal tissue specimens to determine whether methylation patterns could act as stage-dependent biomarkers of gastrointestinal tumorigenesis. Next, we developed a novel strategy that uses single-step modification of DNA with sodium bisulfite and fluorescence polymerase chain reaction methodology to measure aberrant methylation in fecal DNA. Methylation of the RASSF2 and SFRP2 promoters was analyzed in 296 fecal samples obtained from a variety of patients, including 21 with gastric tumors, 152 with colorectal tumors, and 10 with non-neoplastic or inflammatory lesions in the gastrointestinal lumen.
Results: Analysis of DNA from tissues showed presence of extensive methylation in both gene promoters exclusively in advanced gastric and colorectal tumors. The assay successfully identified one or more methylated markers in fecal DNA from 57.1% of patients with gastric cancer, 75.0% of patients with colorectal cancer, and 44.4% of patients with advanced colorectal adenomas, but only 10.6% of subjects without neoplastic or active diseases (difference, gastric cancer vs undiseased = 46.5%, 95% confidence interval (CI) = 24.6% to 68.4%, P < .001; difference, colorectal cancer vs undiseased = 64.4%, 95% CI = 53.5% to 75.2%, P < .001; difference, colorectal adenoma vs undiseased = 33.8%, 95% CI = 14.2% to 53.4%, P < .001).
Conclusions: Methylation of the RASSF2 and SFRP2 promoters in fecal DNA is associated with the presence of gastrointestinal tumors relative to non-neoplastic conditions. Our novel fecal DNA methylation assay provides a possible means to noninvasively screen not only for colorectal tumors but also for gastric tumors.
| CONTEXT AND CAVEATS Prior knowledge A stool-based screening test for colorectal cancer has long been sought. Most recently, studies have centered on the analysis of biomarkers in DNA from exfoliated tumor cells. Study design The degree of DNA methylation at the RASSF2 and SFRP2 gene promoters was analyzed in 788 colorectal and gastric tumor specimens to establish these methylation patterns as stage-dependent biomarkers of gastrointestinal tumorigenesis. Next, a highly sensitive assay was developed for the detection of these methylation patterns among 296 fecal DNA specimens that included many from patients with colorectal or gastric tumors. Contribution Extensive methylation at the RASSF2 and SFRP2 promoters was much more likely to be found in advanced gastric and colorectal tumors than in normal tissue. Fecal DNA methylation and recovery were also much more likely in stool samples from diseased patients. One or more methylation markers was detected in fecal DNA from 57% of gastric cancer patients, 75% of colorectal cancer patients, and 44% of subjects with advanced colorectal adenomas, but only 10.6% of undiseased patients. Implications This method shows promise as a noninvasive screening tool not only for colorectal cancer but also for gastric cancer. Limitations The analysis of additional biomarkers may help to enhance the sensitivity of the assay, to reduce the detection of false positives, and to distinguish gastric from colorectal cancers. From the Editors
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Manuscript received June 30, 2009; revised June 30, 2009; accepted July 16, 2009.
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J Natl Cancer Inst 2009 101: 1221.