Noninvasive stool test for colorectal cancer unaffected by variables

April 3, 2012

A study presented today by Mayo Clinic researchers at the American Association for Cancer Research (AACR) Annual Meeting 2012 in Chicago identified two genes that are optimal targets to be analyzed in a new noninvasive test for colorectal cancer developed by Mayo Clinic, in collaboration with Exact Sciences Corporation. The test uses a small sample of a patient's stool to check for specific DNA changes, known as gene methylation, that occur as cancer develops. The test can quickly detect both early stage cancer and precancerous polyps.

Research on an investigational DNA methylation test for colorectal cancer demonstrated that the only clinical variable that influenced test results was age, according to results presented at the AACR Annual Meeting 2012, held here March 31 - April 4.

"There was a progressive increase in background methylation levels that varied widely between methylation markers tested as a patient aged," said David Ahlquist, M.D., professor of medicine and a consultant in gastroenterology and hepatology at the Mayo Clinic in Rochester, Minn. "For example, median background methylation levels of the TFPI2 gene increased 49 percent in patients from age 50 to age 80, whereas levels for the BMP3 gene increased by only 0.2 percent across this age range."

His group at the Mayo Clinic, in collaboration with Exact Sciences, developed the multimarker molecular , which is highly sensitive to the critical targets of early-stage cancers and precancerous adenomas, he said.

"This test, if broadly applied, should have a very important impact on reducing both the mortality and incidence of colorectal cancer," Ahlquist said.

The researchers examined common patient variables, including age, sex, race, , , body mass and medication use in 500 patients undergoing or polyp follow-up. Patients had a normal colonoscopy in the last three years.

With the exception of age, none of the variables influenced test results, nor did family history of colorectal cancer or polyps or personal history of polyps. These results mean that "patients don't have to change their lifestyle to have this test," Ahlquist said. "That was important from a patient-friendly standpoint for a test like this and could benefit compliance."

Researchers have selected the two markers least affected by age for further test development and validation based on these study results.

"If we can minimize the false positives, that will reduce the cost of the whole screening program by avoiding unnecessary colonoscopies," Ahlquist said.

The screening test is currently undergoing FDA validation in a multicenter study in the United States and Canada, which is expected to be completed in the fall. The Mayo Clinic and Ahlquist have a financial interest in the technology referenced in this announcement.

Explore further: New test offers greater accuracy in early detection of colorectal cancer

Related Stories

New test offers greater accuracy in early detection of colorectal cancer

January 19, 2012
Results of two studies suggest that a new, investigational colorectal cancer screening test developed in a collaboration between Mayo Clinic and Exact Sciences Inc. of Madison, Wis., is highly accurate and significantly more ...

ACP releases new colorectal cancer screening guidance statement

March 5, 2012
The American College of Physicians (ACP) today issued a new guidance statement for colorectal cancer screening. Colorectal cancer is the second leading cause of cancer-related deaths for men and women in the United States. ...

Recommended for you

Researchers unravel novel mechanism by which tumors grow resistant to radiotherapy

November 23, 2017
A Ludwig Cancer Research study has uncovered a key mechanism by which tumors develop resistance to radiation therapy and shown how such resistance might be overcome with drugs that are currently under development. The discovery ...

African Americans face highest risk for multiple myeloma yet underrepresented in research

November 23, 2017
Though African-American men are three times more likely to be diagnosed with multiple myeloma, a type of blood cancer, most scientific research on the disease has been based on people of European descent, according to a study ...

Encouraging oxygen's assault on iron may offer new way to kill lung cancer cells

November 22, 2017
Blocking the action of a key protein frees oxygen to damage iron-dependent proteins in lung and breast cancer cells, slowing their growth and making them easier to kill. This is the implication of a study led by researchers ...

One-size treatment for blood cancer probably doesn't fit all, researchers say

November 22, 2017
Though African-American men are three times more likely to be diagnosed with a blood cancer called multiple myeloma, most scientific research on the disease has been based on people of European descent, according to a study ...

One in four U.S. seniors with cancer has had it before

November 22, 2017
(HealthDay)—For a quarter of American seniors, a cancer diagnosis signals the return of an old foe, new research shows.

Combination immunotherapy targets cancer resistance

November 22, 2017
Cancer immunotherapy drugs have had notable but limited success because in many cases, tumors develop resistance to treatment. But researchers at Yale and Stanford have identified an experimental antibody that overcomes this ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.