FDA Approves DNA-Based Colorectal Cancer Test

Nancy Crotti

August 13, 2014

4 Min Read
FDA Approves DNA-Based Colorectal Cancer Test

People over 50, rejoice! The FDA has approved a non-invasive test for colorectal cancer, and it may not take years to obtain.

Mayo Clinic gastroenterologist David Ahlquist co-invented the test, Cologuard, which detects the presence of hemoglobin and biomarkersin DNA cells shed by large polyps as stool moves through the large intestine and rectum. Patients at average risk for colon cancer will be able to obtain the $599 test from their health care provider and use it at home, according to a press release by manufacturer Exact Sciences (Madison, WI).

In a clinical trial of 10,023 subjects, Cologuard detected 92% of colorectal cancers and 42% of advanced adenomas, while the fecal immunochemical test (FIT), a commonly used, non-invasive screening test that detects blood in the stool, detected 74% of cancers and 24% of advanced adenomas, according to the FDA.

Cologuard was less accurate than FIT at identifying subjects negative for colorectal cancer or advanced adenomas. FIT provided accurate negative screening results for 95% of the study population while Cologuard correctly gave a negative screening result for 87%. Results from Exact Science's DeeP-C Study were published in April 2014 in the New England Journal of Medicine's "Multi-target Stool DNA Testing for Colorectal-Cancer Screening."

The test broke other ground. FDA and the Centers for Medicare and Medicaid Services selected Cologuard to collaborate on their first parallel review pilot program to reduce as many as six months from the time between FDA approval and Medicare or Medicaid coverage.

A final national Medicare/Medicaid coverage determination should be posted in October or November 2014 after a public comment period, according to CMS. Exact Sciences plans to make Cologuard available in select European countries, pending CE Mark.

Mayo licensed the technology behind Cologuard to Exact Sciences and will share equity and royalties with Ahlquist. Mayo's share will support its not-for-profit mission in patient care, education and research.

Most colorectal cancers start as abnormal raised or flat tissue on the wall of the large intestine or rectum. Some very large polyps, or advanced adenomas, and are more likely than smaller polyps to progress to cancer, according to the FDA.

Colorectal cancer primarily affects people age 50 and older. Among cancers that affect both men and women, it is the third most common cancer and the second leading cause of cancer-related death in the United States, according to the Centers for Disease Control and Prevention (CDC).

The CDC estimates that if everyone age 50 or older had recommended regular screening tests at least 60 percent of colorectal cancer deaths could be avoided.

One of those tests, the dreaded colonoscopy, is not going away, however. Patients with positive Cologuard test results will be advised to undergo a diagnostic colonoscopy.

Cologuard's approval also does not change current practice guidelines for colorectal cancer screening. The U.S. Preventive Services Task Force does not recommend fecal DNA testing to screen adults at average risk. The task force recommends adults age 50 to 75 be screened using fecal occult blood testing, sigmoidoscopy, or colonoscopy.

CMS proposes to cover the Cologuard test once every three years for Medicare beneficiaries who meet all of the following criteria:

  • age 50 to 85 years;

  • asymptomatic (no signs or symptoms of colorectal disease, including but not limited to lower gastrointestinal pain, blood in stool, positive guaiac fecal occult blood test or fecal immunochemical test); and

  • average risk of developing colorectal cancer (no personal history of adenomatous polyps, of colorectal cancer, or inflammatory bowel disease, including Crohn's Disease and ulcerative colitis; no family history of colorectal cancers or an adenomatous polyp, familial adenomatous polyposis, or hereditary nonpolyposis colorectal cancer).

Eric Hargis, CEO of the patient advocacy group Colon Cancer Alliance, said in a statement that having Cologuard as another option for people who have resisted getting a colonoscopy could save many lives and increase screening compliance rates.

Nancy Crotti is a contributor to Qmed and MPMN.

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About the Author(s)

Nancy Crotti

Nancy Crotti is a frequent contributor to MD+DI. Reach her at [email protected].

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