Long-term use of low-dose Aspirin may lower risk of colon cancer

A new study has found that taking one or two low-dose aspirins every day for at least 5 years could reduce the risk of developing colon cancer in men and women.

Colon cancer is the third most common cancer in the world. Excluding skin cancers, it is the third most common cancer diagnosed in both men and women in the US. In UK, 16,187 deaths were reported from bowel cancer in 2012.

The study published in the journal Annals of Internal Medicine found that men and women who took one or two low doses (75 to 150 mg) of aspirin a day for at least five years saw a 27 percent lower risk of bowel cancer.

Although, earlier studies had suggested that aspirin and non-steroid anti-inflammatory drugs (NSAIDs) may prevent colorectal cancer, it was unclear on the amount, and the length of time in order to achieve the benefits. [Read more Regular coffee drinking may cut your liver cancer risk by half]

The latest study was done by researchers at the Department of Clinical Epidemiology at Aarhus University Hospital in Denmark. 

The participants included 10,280 adults with first-time colorectal cancer and 102,800 adults who acted as the control group. Diet, weight and exercise were excluded from the study. 

"It is important to evaluate the association between aspirin or other NSAIDs in the general population, as well as within selected study populations of high-risk individuals with colorectal cancer, including persons with familial/hereditary disposition, previous history of colorectal adenomas or cancer or obesity, while balancing the chemopreventive effects against the potential harms," said Soren Friis, senior scientist and associate professor at Aarhus University Hospital.

“Unless low-dose aspirin is taken continuously, there is little protection against colorectal cancer,” Dr. Friis told Reuters Health. 

People should also take into account that long-term aspirin use could cause gastrointestinal bleeding. Taking other types of NSAIDs for a long time could increase the risk of heart attack and stroke.

Researchers also noted that the findings do not prove that painkillers reduce the risk of colon cancer, but there is a connection between the two. 

"The protective association is certainly amazing, and it's a good example of how everyday drugs can have unexpected benefits," said study co-author Dr. John Baron of University of North Carolina School of Medicine.

"But there are also potential risks ... I don't think we should imply or recommend that these medications be taken for cancer prevention without working closely with a physician.”