Daily aspirin could keep cancer cells from spreading

You may know someone who takes a low-dose or “baby” aspirin every day.

Their doctor has likely prescribed it to prevent a second heart attack or ischemic stroke. Both involve blood clots blocking major arteries, and aspirin interferes with the process of clot formation.

However, as often happens in research, scientists have accidentally discovered that the very mechanism that helps aspirin prevent blood from clotting can also stop cancer from spreading.

How aspirin allows T cells to kill cancer

A team of scientists at the University of Cambridge wanted to investigate the process by which cancer metastasizes or spreads.

Specifically, they aimed to gain a deeper understanding of how the immune system responds to metastasis.

While cancer cells in an original tumor often develop the ability to suppress the immune system, lone cancer cells that have spread to other parts of the body are more vulnerable to attacks by T cells, which can recognize and kill metastatic cancer cells.

Working with mice, the researchers discovered a gene that produces a protein called ARHGEF1. They also found that mice who lacked this gene had less metastasis of primary cancers to other parts of their bodies.

They soon discovered why: ARHGEF1 suppresses the T cells that would otherwise normally detect and kill metastasized cancer cells. That’s why mice that did not have the ARHGEF1-producing gene had less metastasis.

Of course, the scientists dug further for a target that could manipulate that action, hoping it would lead them to a potential therapy to reduce the risk of cancer metastasis — and they found it…

They saw that ARHGEF1 is switched on when T cells are exposed to a clotting factor called thromboxane A2 (TXA2). And guess what?

Aspirin reduces the production of TXA2, leading to anti-clotting effects, which is why aspirin is sometimes suggested for the prevention of heart attacks and strokes.

In other words, the research found that aspirin prevents cancers from spreading by decreasing TXA2 and releasing T cells from suppression, allowing them to seek and destroy cancer cells that attempt to spread.

Aspirin as cancer therapy: pros, cons

This discovery holds particular promise for people whose cancer has just begun to spread.

“Most immunotherapies are developed to treat patients with established metastatic cancer, but when cancer first spreads there’s a unique therapeutic window of opportunity when cancer cells are particularly vulnerable to immune attack,” says Professor Rahul Roychoudhuri, the study’s lead author.

“We hope that therapies that target this window of vulnerability will have tremendous scope in preventing recurrence in patients with early cancer at risk of recurrence.”

Previous research has shown that aspirin may also be beneficial for cancer prevention, potentially activating genes that protect against colorectal cancer.

However, it’s important to note that you should never “self-medicate” by taking a daily aspirin without first talking with your doctor.

If you are taking a blood thinner such as Warfarin or Heparin, your doctor will almost certainly advise against adding a daily aspirin to your regimen. That’s because it would increase the anti-coagulant effect on your body and could cause internal bleeding.

A few other things to consider:

• The most recent recommendation from the U.S. Preventive Services Task Force (USPSTF) is for adults 60 years or older not to start daily low-dose aspirin use for the primary prevention of cardiovascular disease.
• People with pre-existing kidney disease should avoid aspirin, as it acts like a non-steroidal anti-inflammatory drug (NSAID). Reduced blood flow to the kidneys can cause further damage.
• Aspirin can irritate the stomach lining and worsen existing stomach ulcers.
• Aspirin may significantly increase the risk of bleeding, including bleeding on the brain and gastrointestinal hemorrhages.

Be safe and talk to your doctor before starting a daily cancer regimen.

Sources:

Scientists discover how aspirin could prevent some cancers from spreading — Eureka Alert

Aspirin prevents metastasis by limiting platelet TXA2 suppression of T cell immunity — Nature