Can aspirin help prevent colorectal cancer development?

A new study published by Wiley online in CANCER revealed that long-term daily use of aspirin can aid in preventing the development and progression of colorectal cancer. The study suggested that aspirin may achieve this by enhancing specific aspects of the body's immune response against cancer cells.

Colorectal cancer is a type of cancer that starts in the colon or rectum, typically beginning as a growth called a polyp. Aspirin may help prevent colorectal cancer by reducing inflammation and inhibiting the growth of polyps. Additionally, aspirin may enhance the body's immune response against cancer cells. Long-term daily use of aspirin has been associated with a lower risk of developing and progressing colorectal cancer, making it a potential preventive measure against this disease.

To investigate the effects of aspirin on colorectal cancer, researchers obtained tissue samples from 238 patients who underwent surgery for colorectal cancer in 2015–2019, 12% of whom were aspirin users.

Researchers discovered that tissue samples from aspirin users showed less cancer spread to lymph nodes and higher immune cell infiltration into tumors compared to non-users. In lab studies, aspirin exposure increased CD80 protein expression in immune cells, boosting their ability to alert other immune cells of tumor presence. Rectal cancer patients who used aspirin had higher CD80 expression in healthy rectal tissue, indicating a potential pro-immune surveillance effect of aspirin

“Our study shows a complementary mechanism of cancer prevention or therapy with aspirin besides its classical drug mechanism involving inhibition of inflammation. Aspirin is absorbed in the colon by passive diffusion to a significant degree. Its absorption is linear and depends on concentration along the bowel, and in the rectum, the concentration of orally administered aspirin can be much lower than in the rest of the colon. Thus, if we want to take advantage of its effects against colorectal cancer, we should think of how to guarantee that aspirin reaches the colorectal tract in adequate doses to be effective,” said principal investigator Marco Scarpa MD, PhD, of the University of Padova.

Reference:Marco Scarpa, MD, PhD, et al; IMMUNOREACT 7: Regular aspirin use is associated with immune surveillance activation in colorectal cancer; Journal: Cancer.