New study results show that aspirin may reduce the risk of colorectal cancer. The common over the counter medication may benefit those with a specific type of gene.

The results were reported by a multi-institutional team that analyzed data and related material from two long-term studies. In total, the studies involved nearly 128,000 participants.

The researchers discovered that individuals who have high levels of a certain gene product, 15-hydroxyprostaglandin dehydrogenase (15-PGDH) RNA, and who took aspirin, greatly reduced their chances of developing colorectal cancer. Aspirin does not benefit those who have low levels of 15-PGDH in their colon.

Researchers from Case Western Reserve University School of Medicine, Dana Farber Cancer Institute, Harvard University, Massachusetts General Hospital, and University Hospitals Case Medical Center conducted the study.

The findings, which appear in a recent edition of Science Translational Medicine, offer the first evidence that helps to show why aspirin only benefits some people.

Sanford Markowitz, MD, PhD, senior author and Ingalls Professor of Cancer Genetics at Case Western Reserve School of Medicine, said in a statement, “If you looked at the folks from the study who had high 15-PGDH levels and took aspirin, they cut their risk of colon cancer by half.” He continued, “If you looked at the folks from the study that were low for 15-PGDH, they did not benefit at all from taking aspirin. These findings represent a clean Yes-No about who would benefit from aspirin.”

Colorectal cancer is the second-highest cause of cancer-related deaths across the country, according to the American Cancer Society. An estimated 137,000 Americans will develop the disease in 2014, and 50,000 will die from it in the same year.

Funding for the study was provided in part by Entertainment Industry Foundation’s National Colorectal Cancer Research Alliance, which Katie Couric and colleagues founded in 2000. Couric’s husband, Jay Monahan, died from colon cancer in 1998.