Researchers studying 14,000 patients with gastrointestinal cancer in the Netherlands have found that patients who took aspirin following their diagnosis were twice as likely to be alive after four years as those who did not take the drug.

According to the report, which was presented at the annual meeting of the 2015 European Cancer Congress in Vienna, the impact on survival was seen after adjusting for sex, age, stage of cancer, surgery, radiotherapy, chemotherapy, and other medical conditions or disorders that could influence death rates. 

The study included patients who were diagnosed with cancer of the colon (42.8%), rectum (25.4%), and esophagus (10.2%) between 1998 and 2011. 

To determine how aspirin use after a diagnosis of gastrointestinal cancer had an impact on survival, the researchers linked patient data with drug-dispensing information from a pharmaceutical registry. Overall, 30.5% of patients used aspirin before their cancer diagnosis, 8.3% used aspirin only after diagnosis, and 61.1% did not use aspirin at all. The patients were followed for a median of 48.6 months, with 28% surviving for at least five years. 

The researchers found that patients using aspirin after their diagnosis had survival rates twice as high as those who did not use it. Although the exact mechanism underlying the anticancer effect of aspirin is unclear, the researchers suggested that its antiplatelet effect may be a factor. 

Platelets are a blood component whose function is to stop bleeding by clumping and clogging blood vessel injuries. Circulating tumor cells are thought to be protected from the immune system because they are surrounded by platelets. Aspirin inhibits platelet function and therefore allows the immune system to recognize the tumor cells and eliminate them. 

According to the researchers, medical research is focusing on more personalized medicine, but many personalized treatments are expensive and useful only in small populations. They believe that their research shows the opposite. It demonstrated the benefit of an inexpensive, well-established, and easily obtainable drug in a large group of patients. 

Following up from the study, a randomized controlled trial is investigating the effect of a daily, low dose of 80 mg of aspirin on the survival of older adult patients with colorectal cancer in the Netherlands. 

The current study contributes to the research supporting the beneficial use of aspirin as an adjunct therapy for gastrointestinal cancers, but the exact dose and duration of aspirin use and the risk/benefit ratios of aspirin use remain to be determined.