Aspirin Linked to Risk Reduction in Several Cancers of the Digestive Tract

The largest and most comprehensive analysis of data for the link between aspirin and cancers of the digestive tract has shown that not only is aspirin associated with a significant reduction in the risk of developing bowel cancer but also several other cancers, including some that are almost invariably fatal, such as pancreatic and liver cancers.

The analysis, published in the cancer journal Annals of Oncology, found reductions in the risk of such cancers between 22% and 38%. Researchers examined evidence from 113 observational studies investigating cancers in the general population published up to 2019, of which 45 centered on bowel cancer and included 156,000 cases. In addition to bowel cancer, the cancers investigated included those of the head and neck, esophagus, stomach, the gastric cardia, liver, gallbladder and bile ducts, and pancreas.

Researchers found that regular use of aspirin, defined as taking at least 1 or 2 tablets per week, was associated with a significant reduction in the risk of developing all these cancers, apart from head and neck cancer.

Specifically, aspirin use was linked to 27% reduced risk of bowel cancer (45 studies), 33% reduced risk of esophageal cancer (13 studies), 39% reduced risk of gastric cardia (10 studies), 36% reduced risk of stomach cancer (14 studies), 38% reduced risk of hepatobiliary cancer (5 studies), and 22% reduced risk of pancreatic cancer (15 studies). Ten studies of head and neck cancer did not show a significant reduction in risk.

The research findings on bowel cancer support the concept that higher aspirin doses are associated with a larger reduction in the risk of the disease. However, the choice of dose should also take into consideration the potential risk of stomach bleeds, which increases with higher aspirin doses. Compared with patients who did not take aspirin regularly, the risk of bowel cancer declined in patients who regularly used aspirin for up to 10 years. The risk was reduced by 4% after 1 year, 11% after 3 years, 19% after 5 years and 29% after 10 years.

The findings suggest that there is a beneficial effect of aspirin in the prevention of bowel and other cancers of the digestive tract, according to the study authors. The results for bowel, esophageal, and pancreatic cancers are consistent with evidence from clinical trials on aspirin in the prevention of heart and blood vessel diseases, according to the study.

Additionally, the results for pancreatic and other digestive tract cancers may have implications for the prevention of these highly lethal diseases. For pancreatic cancer, researchers found that the risk of the disease declined by 25% after 5 years among people who took aspirin regularly compared with those who did not.

The study authors noted that taking aspirin for the prevention of any cancer should only be done in consultation with a doctor. In addition to stomach bleeds, adverse events of aspirin include bleeding in other parts of the body and occasionally hemorrhages, according to the study.

Reference

• Aspirin Linked to Reduction in Risk of Several Cancers of the Digestive Tract. ESMO website. Published April 16, 2020. https://www.esmo.org/newsroom/press-office/aspirin-reduction-in-risk-digestive-tract-annals-of-oncology. Accessed April 17, 2020.