Taking Aspirin to Lower Cancer Risk – When Your Genes Might Defy You

When Felix Hoffman, a German chemist working for Bayer, wanted to develop his new drug aspirin in 1897, he was promptly ignored. He was told his drug had an “enfeebling” effect on the heart, making it a product of no value. Lucky for us, that wasn’t the end of the story.

Nowadays, aspirin is one of the most widely used drugs to treat fever and inflammation. The US Preventative Services Task Force even recommends using low-dose aspirin for the prevention of cardiovascular disease and colorectal cancer in people aged 50 to 59. Indeed, several studies link low-dose aspirin to a decreased risk of heart disease. Others show that aspirin could be effective for both the prevention and treatment of colorectal cancer. BUT, according to one study from the Fred Hutchinson Cancer Research Centre, the benefits of this anti-inflammatory drug on colorectal cancer may depend on your genes.

Aspirin works by blocking an enzyme called cyclooxygenase, which controls inflammation and blood clotting. While aspirin is generally well tolerated, in some people it can cause dyspepsia (indigestion) and stomach ulcers, and increase the risk of intestinal bleeding. There is good evidence that long-term use (5-10 years) of low-dose aspirin will lower the risk of getting colorectal cancer and increase the survival rate in patients. However, whether these benefits outweigh the harmful effects of aspirin, is a topic that remains controversial.

The study by Nan and Colleagues adds to this debate, emphasizing the need to consider genetic variation when using aspirin therapy. These researchers gathered genetic data from 8,634 colorectal cancer patients and 8,553 healthy individuals. In agreement with previous studies, they found an association between the use of non-steroidal anti-inflammatory drugs (NSAIDs) and the risk of colorectal cancer. People who used aspirin or NSAIDs regularly (2-3 days/week), were 30% less likely to develop colorectal cancer. But, there was a catch! Genetic markers near two genes, MGST1 and IL16, influenced the positive affects of aspirin on cancer risk. 

When people with the most common versions of these markers used NSAIDs regularly, it associated with a decreased risk of cancer. But, if they happened to inherit the rare variant near the IL6 geneNSAID use had no significant affect on the cancer risk. Even worse, people who inherited the rare variant near the MGST1 gene (4% of the people in the study), were actually at increased risk of developing cancer when they used aspirin.

The bottom line – aspirin therapy needs to be personalized. Multiple factors like the age of a person, health complications, and their genetic background should be considered to properly assess their risk.

Aspirin is one of the most widely used anti-inflammatory drugs in the world. But, no health organization endorses taking it for the sole purpose of preventing colorectal cancer. Mainly because the decision of who should be taking aspirin as a preventative drug is not an easy one. The Aspirin and Colorectal Cancer Risk DNA Test can help you decide whether it is the  best preventative method for you. You may not be able to change your genes, but you can at least ensure that you are not risking your health when you practice prevention.