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Study Finds Noninvasive Colon Cancer Screening May Be Promising for African Americans

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Key Points

  • Though African Americans are statistically at higher risk for colorectal cancer, they are less likely to be screened than other populations.
  • Stool DNA sensitivity and specificity for detecting advanced lesions and all adenomas in African Americans were similar to or exceeded those of other racial groups and in some cases were more sensitive than fecal immunochemical testing.
  • Researchers are hopeful stool DNA testing can be used as an alternative for those who desire a less invasive or more affordable option than colonoscopy.

     

In a first-of-its-kind clinical trial, physician-scientists at University Hospitals (UH) Case Medical Center, Seidman Cancer Center, and Case Western Reserve University School of Medicine found that a new, noninvasive technology for colon cancer screening is a promising alternative to colonoscopy for African Americans. Their study compared the effectiveness of stool DNA testing with colonoscopy for detecting large colon polyps.

Multitarget Stool DNA Testing

Multitarget stool DNA testing detects colon cancer at its earliest stages, based on analysis of stool DNA. Developed in the laboratory of Sanford Markowitz, MD, PhD, oncologist with UH Seidman Cancer Center and Professor of Medicine at Case Western Reserve University School of Medicine, stool DNA testing is a recommended screening by the American Cancer Society.

“Colon cancer is the second leading cause of cancer deaths in the United States but is a preventable disease,” said Gregory Cooper, MD, Co-Program Leader for Cancer Prevention, UH Seidman Cancer Center and Professor, Case Western Reserve University School of Medicine. “Early detection through screening can prevent the development of colon cancer. This promising new test has the potential to improve colon cancer screening rates and decrease mortality from this deadly disease.”

Study Details

In the study presented at Digestive Disease Week and subsequently published in Gastroenterology, Dr. Cooper and colleagues studied data from 460 subjects for stool DNA and 476 subjects using another noninvasive test called fecal immunochemical testing. A little more than one-third of the subjects were African American.

According to the results, the sensitivity and specificity of stool DNA testing for advanced lesions and all adenomas in African Americans were similar to or exceeded those of other racial groups, and in some respects, the sensitivity was higher than that for fecal immunochemical testing.

New Option for At-Risk Groups

“Given the known racial disparities in colonoscopies between African Americans and other racial groups, this noninvasive technology may offer a promising screening alternative,” said Dr. Cooper.

Colonoscopy is considered the gold standard for screening because of its ability not only to locate but remove precancerous polyps. Medical guidelines suggest all adults over age 50 should undergo colonoscopy, with certain risk factors for screening at an earlier age. However, according to research conducted by Dr. Cooper, many adults do not follow these national guidelines, and evidence indicates that African Americans are less likely than whites to get screening tests for colorectal cancer.

Although all men and women are at risk for colon cancer, some people are at higher risk for the disease because of age, lifestyle, or personal and family medical histories. According to studies, African Americans are at a higher risk for the disease than other populations. Research shows that African Americans are being diagnosed at a younger average age than other people. Therefore, some experts suggest that African Americans should begin their screening at age 45.

“Colonoscopy is truly the best test, but it has its limitations and is vastly underused by the public,” says Dr. Cooper, who is Clinical Primary Investigator for the study. “Stool DNA testing is emerging as a promising alternative for patients who do not want to undergo colonoscopy or do not have access to the procedure. It also can be beneficial for patients during the years in between colonoscopies.”

Dr. Markowitz and his team played an intimate role in developing the new technology for DNA screening for colon cancer. They discovered a specific DNA change, methylation of the vimentin gene, which takes place in colon cancers and then developed techniques for sensitively detecting this change in DNA shed from colon cancers in the stool. Their technology has been licensed by EXACT Sciences Corporation for commercial development and expanded to include a larger panel of genes.

“Among our guiding principles is to pursue and implement breakthrough medical advancements and practices to deliver superior clinical outcomes for our patients,” said Stanton Gerson, MD, Director, UH Seidman Cancer Center and Case Comprehensive Cancer Center, Case Western Reserve University. “Noninvasive stool DNA testing screening is an exciting example of this principle in action and can potentially have a dramatic impact on increasing screening rates and decreasing mortality.”

Dr. Cooper is the corresponding author of the Gastroenterology article.

The study is funded as part of the National Cancer Institute’s Specialized Program of Research Excellence (SPORE) in Gastrointestinal (GI) Cancers award to Case Western Reserve University School of Medicine. 

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.


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