Cancer is a leading cause of morbidity and death worldwide, and its prevalence is predicted to increase in the next few years. Cancer prevention strategies include making healthy lifestyle choices and getting tested if at risk. New research suggests that a small dose of aspirin may help prevent the formation of cancer cells and explains how.
In terms of prevention, the Centers for Disease Control and Prevention (CDC) recommend making healthy lifestyle and dietary choices, such as avoiding tobacco and alcohol, as well as staying physically active and eating plenty of fruits and vegetables.
New research reinforces the idea that low-dose aspirin intake may also help to prevent cancer and inhibit the proliferation of cancer cells.
The suggestion that a small dose of aspirin may help to prevent cancer is not new. In September 2015, the United States Preventive Services Task Force recommended the daily use of a small dose of aspirin to help to prevent cardiovascular disease and colorectal cancer.
However, the new research also explains the process by which a low dose of aspirin may indeed inhibit cancer cell proliferation and metastasis.
Aspirin indirectly inhibits oncoprotein responsible for malignant cells
The research was conducted by scientists from Oregon Health and Science University (OHSU) in collaboration with Oregon State University (OSU), and the results were published in the journal AJP-Cell Physiology.
"The benefit of aspirin may be due to its effect on blood cells called platelets, rather than acting directly on tumor cells," says senior author Owen McCarty, a professor in the Department of Biomedical Engineering at OHSU.
Platelets are tiny blood cells that help a healthy body to form clots, in order to stop the bleeding when necessary.
It seems that our blood platelets also increase the levels of a certain protein that may support cancer cells and help them to spread. This "oncoprotein" is called c-MYC.
The biological function of c-MYC is to regulate the expression of over 15 percent of all the genes of the human body. The c-MYC regulator controls the life-and-death cycle of cells, the synthesis of proteins, and the cells' metabolism.
However, research has shown that in human cancers, this oncogene is overexpressed.
The researchers from this latest study explain that aspirin reduces the ability of blood platelets to raise levels of the c-MYC oncoprotein.
"Our work suggests that the anti-cancer action of aspirin might be in part as follows: during their transit in the blood, circulating tumor cells interact with platelets, which spur tumor cell survival by activating oncoproteins such as c-MYC. The inhibition of platelets with aspirin therapy reduces this signaling between platelets and tumor cells, thus indirectly reducing tumor cell growth."
Craig Williams, a professor in the OSU/OHSU College of Pharmacy and co-author of the study, further explains the process.
"Early cancer cells live in what is actually a pretty hostile environment, where the immune system regularly attacks and attempts to eliminate them," he says. "Blood platelets can play a protective role for those early cancer cells and aid metastasis. Inhibition with aspirin appears to interfere with that process and c-MYC may explain part of that mechanism."
Low-dose aspirin may be 'safe and efficacious' in preventing cancer
This is the first time that a study has shown the ability of platelets to regulate the expression of c-MYC in cancer cells.
The researchers note that almost a third of colon cancer patients and 42 percent of patients with pancreatic cancer had overexpression of the c-MYC oncoprotein.
They also point out that the impact aspirin has on blood platelets is just as effective in high doses as it is at low ones. As a result, clinicians can weigh up the risks and benefits of aspirin intake, as well as reduce the risk of bleeding - which is a common side effect of ingesting too much aspirin.
The authors emphasize the crucial role of physicians and healthcare professionals when considering even a low-dose aspirin intake.
"Because the interaction between platelets and cancer cells is believed to occur early [...] the use of anti-platelet doses of aspirin might serve as a safe and efficacious preventive measure for patients at risk for cancer," the authors conclude.