Genes, Aspirin and Colon Cancer

BRAF gene status affects the ability of aspirin to lower colorectal cancer risks

(RxWiki News) Aspirin is far more than a pain reliever. This medicine is now known to play a role in lowering risks of some types of cancer. Recent research zeros in on the good aspirin does and doesn’t do.

Regular aspirin use may lower the risk of colorectal cancer in people who have a gene called BRAF that isn’t altered in anyway.

But aspirin did not seem to lower colorectal cancer risks in people who have a mutated BRAF gene, according to a recently released study.

"Find out if aspirin therapy is right for you."

In a study led by Reiko Nishihara, PhD, of the Dana-Farber Cancer Institute in Boston, researchers looked at how aspirin affected colorectal cancer risks in people with mutant and non-mutated (wild-type) BRAF genes. 
These investigators sent questionnaires every other year to people who had participated in the 1980 Nurses' Health Study and the 1986 Health Professionals Follow-up Study. These two studies involved nearly 128,000 people.

The researchers followed these individuals until July 2006 to track cancer incidence and until January 2012 for cancer mortality.

Among the participants, 1,226 cases of colon and rectal cancers were diagnosed.

Folks who took aspirin on a regular basis had a 27 percent lower risk of BRAF wild-type cancer than people who did not take aspirin.

Aspirin use did not lower the risk of BRAF-mutated colorectal cancer, the study found.

"The association of aspirin tablets per week with cancer risk differed significantly by BRAF mutation status," the authors wrote.

"Compared with individuals who reported no aspirin use, a significantly lower risk of BRAF wild-type cancer was observed among individuals who used six to 14 tablets of aspirin per week and among those who used more than 14 tablets of aspirin per week," they wrote.

Taking aspirin after a colorectal cancer diagnosis did not affect survival, according to the research team.

The authors concluded that data from this study "...provide additional support for a causal association between aspirin use and risk reduction for a specific subtype of colorectal cancers. Accumulating evidence supports preventive effect of aspirin against colorectal cancer."

In an accompanying editorial, Boris Pasche, MD, PhD, of the University of Alabama at Birmingham, noted that the two studies involved in this research involved mainly white people.

Since black people have a higher risk of colorectal cancer than whites, Dr. Pasche suggested that aspirin studies involving blacks would be important going forward.

Findings from this study were published in the June 26 issue of JAMA.

The National Institutes of Health, the Bennett Family Fund for Targeted Therapies Research and the National Colorectal Cancer Research Alliance funded the study.

Several authors disclosed financial relationships with various pharmaceutical companies, including Amgen, Bayer, Millennium, Novartis and Pfizer, as well as other medical organizations.

Review Date: 
June 26, 2013