Bioethics Blogs

Precision Medicine: Who Benefits from Aspirin to Prevent Colorectal Cancer?

In recent years, scientific evidence has begun to accumulate that indicates taking aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs) on a daily basis may lower the risk of developing colorectal cancer. Now, a new study provides more precise information on who might benefit from this particular prevention strategy, as well as who might not.

Published in the journal JAMA, the latest work shows that, for the majority of people studied, regular use of aspirin or NSAIDs was associated with about a one-third lower risk of developing colorectal cancer. But the international research team, partly funded by NIH, also found that not all regular users of aspirin/NSAIDs reaped such benefits—about 9 percent experienced no reduction in colorectal cancer risk and 4 percent actually appeared to have an increased risk [1]. Was this just coincidence, or might there be a biological explanation?

By mining mountains of data generated by 10 “cohort” studies that followed large groups of people over long periods of time, the international research team, partly funded by NIH, took aim at a dilemma that confronts many people who take aspirin on a daily basis. While aspirin is often used to relieve pain and to lower risk of heart attack or stroke, it can cause potentially serious bleeding in the stomach, small intestine, or even the brain. So, it would be great to have more precise ways to predict whether the benefits of aspirin are likely to outweigh the risks in an individual patient.

In their meta-analysis involving more than 17,000 people—half of whom had invasive colorectal cancer and half of whom did not—the international research team, led by Andrew Chan of Massachusetts General Hospital in Boston and Ulrike Peters and Li Hsu of Fred Hutchinson Cancer Center in Seattle, identified some relatively uncommon genetic variants that appear to be associated with development of colorectal cancer despite daily use of aspirin or NSAIDs.

The views, opinions and positions expressed by these authors and blogs are theirs and do not necessarily represent that of the Bioethics Research Library and Kennedy Institute of Ethics or Georgetown University.