Colorectal cancer patients with certain genetic backgrounds may benefit more from taking aspirin to prevent cancer reoccurrence, based on a study conducted by researchers at the Baylor Scott & White Health Research Institute.

The study, published in Cancer Prevention Research journal, examined how aspirin influences the growth of cultured colorectal cancer cells with a variety of different mutational backgrounds and aimed to explain why aspirin is more effective in some patients than others. Previous studies have demonstrated that taking 600 milligrams of aspirin per day for two years resulted in a 63 percent reduction in colorectal cancer incidence.

"Aspirin has promising potential for reducing the risk of colorectal cancer, but it's also associated with side effects such as gastrointestinal bleeding, which can be concerning and sometimes fatal," said Ajay Goel, PhD, director of gastrointestinal research and translational genomics and oncology at Baylor Scott & White Research Institute and one of the lead authors of the study. "If we can better predict whether a patient will benefit from taking aspirin to prevent cancer reoccurrence, we can more widely recommend it and potentially save more lives."

Results showed that aspirin slowed growth of cancer cells with multiple different genetic makeups, but was most effective in cells with the PIK3CA gene mutation, a fast–growing type of cancer cell. Findings suggest aspirin's benefits may outweigh its risks for colorectal cancer patients with the mutation, and the difference in cellular responses to aspirin may be important for tailoring its use in cancer prevention and treatment.

"Routine prescription of aspirin as a colorectal cancer preventative has been challenging because its effectiveness at the cellular level can vary and the patient population is genetically diverse," Dr. Goel said. "This study highlights the need for ongoing research into those genetic variances and aspirin's role in cancer treatment and prevention."