Noninvasive Colon Cancer Screening Highly Accurate

Colon cancer screening showed promise at detecting cancer cells without leaving the house

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Colon cancer is a treatable form of cancer when detected early, but many at-risk adults fail to get screened. A new study looked at a highly accurate new test that may change that.

The study showed that Cologuard was highly effective at detecting precancer and cancer of the colon.

The authors of this study noted that Cologuard would not replace colonoscopy, which remained more accurate and allows for the removal of polyps during the procedure.

Cologuard is currently under review by the US Food and Drug Administration (FDA) and is not available for sale in the United States.

"Discuss cancer screening with your doctor if you are over 50."

This study was led by Thomas Imperiale, MD, Professor of Medicine at Indiana University Medical Center in Indianapolis.

The research team looked at 9,989 patients during this clinical trial, called the DeeP-C study, to determine how effectively Cologuard detected cancer and precancer of the colon. The patients were recruited through 90 medical centers in the United States and Canada.

A total of 65 of the participants were found to have colon cancer.

Cologuard is a stool DNA (sDNA) test that analyzes a stool sample for altered DNA, a sign of cancer and precancer, that can be taken at home and mailed in to the lab.

In this study, all the patients received Cologuard, fecal immunochemical test for occult blood (FIT) and a colonoscopy, which is an invasive procedure that allows doctors to view the interior of the colon and rectum.

The data showed that Cologuard was significantly better at detecting cancers and precancerous polyps than FIT.

"Cologuard detection rates of early stage cancer and high-risk precancerous polyps validated in this large study were outstanding and have not been achieved by other noninvasive approaches," said study co-author David Ahlquist, MD, a Mayo Clinic gastroenterologist and co-inventor of the Cologuard test.

"It is our hope that this accurate and user-friendly test will expand screening effectiveness and help curb colorectal cancer rates in much the same way as regular screening, including genetic testing, has done for cervical cancer," Dr. Ahlquist said.

This study showed that cologuard was 92 percent effective in detecting colon cancer overall and 94 percent effective at detecting the earliest stages, stage I and II, which are more easily treated.

"The most important finding of the study is the high sensitivity of Cologuard for curable stage colorectal cancer, which represents the highest sensitivity of any noninvasive test to date," said Dr. Imperiale. "It is also significant to note that these results were achieved in a robustly conducted multicenter study."

Daniel DeMarco, MD, gastroenterologist at Baylor University Medical Center at Dallas and Medical Director of Digestive Disease Technology for Baylor Health Care System gave dailyRx News some interesting points about this research. They are:

  • This is an excellent study, the conclusions are supported by their methods
  • If this test detects the pre-cancerous polyps as shown, it may be a very good non-invasive sets that will ultimately lead to colonoscopy which truly does prevent cancer by removing pre-cancerous polyps.
  • This test is not suitable for individuals who are not suitable to have a colonoscopy (elderly or frail), or who have complex medical problems.
  • Like all new technology, the costs involved with this test will have to be considered.

This study was first published March 20 in New England Journal of Medicine.

This study was funded by Exact Sciences.

Dr. Ahlquist is a scientific advisor, research collaborator and inventor of licensed technology with Exact Sciences, the co-developer of Cologuard.

Review Date: 
March 21, 2014
Last Updated:
May 9, 2014