Study reveals that aspirin helps the body’s immune system detect and target cancer cells.
Long-term daily aspirin use may help prevent the development and progression of colon cancer, but the mechanisms involved were unclear. New research has revealed that aspirin may exert these protective effects by enhancing certain aspects of the body’s immune response against cancer cells. The findings are published by Wiley online at CANCERa peer-reviewed journal of the American Cancer Society.
To investigate the effects of aspirin (a non-steroidal anti-inflammatory drug) on colon cancer, researchers in Italy obtained tissue samples from 238 patients who underwent surgery for colon cancer in 2015-2019, 12% of whom were aspirin users. Patients were enrolled in the METACCRE section of the IMMUNOREACT microenvironment multicenter observational study Treating Adenocarcinoma of the Rectum (IMMUNOREACT 8). The study was funded by the Associazione Italiana per la Ricerca sul Cancro (AIRC) and was carried out mainly at the University Hospital of Padua.
Compared to tissue samples from patients who did not use aspirin, samples from aspirin users showed less spread of cancer to lymph nodes and higher infiltration of immune cells into the tumors. In analyzes of colon cancer cells in the lab, exposure of the cells to aspirin caused increased expression of a protein called CD80 on some immune cells, which enhanced the cells’ ability to alert other immune cells to the presence of tumor-related proteins. Supporting this finding, the researchers found that in rectal cancer patients, aspirin users had higher CD80 expression in healthy rectal tissue, suggesting a pro-immunosuppressive effect of aspirin.
Our study shows a complementary mechanism of cancer prevention or treatment with aspirin besides the classical pharmaceutical mechanism involving the inhibition of inflammation. Aspirin is absorbed in the colon by passive diffusion to a significant extent. Absorption is linear and concentration-dependent across the intestine, and in the rectum, the concentration of orally administered aspirin may be much lower than in the rest of the colon. “So if we want to take advantage of its effects against colon cancer, we have to think about how to guarantee that aspirin reaches the colon in sufficient doses to be effective.”
Marco Scarpa MD, PhD, Principal Investigator, University of Padua
Source:
Journal Reference:
De Simoni, O., et al. (2024) IMMUNOREACT 7: Regular aspirin use is associated with immune surveillance activation in colon cancer. CANCER. doi.org/10.1002/cncr.35297.
