Aspirin vs Cancer Metastasis

Aspirin is a bit of a mixed bag.

In the category of things in its favor, it’s a modest analgesic with few side effects from occasional use, so it’s a good option if you have a headache, for example.

Unless you’re already on blood thinners or having a bleeding disorder, in which case, aspirin is not the thing to reach for.

About aspirin and heart disease

This is actually a complicated one, and we covered it at length in a dedicated main feature. If you want a one-line summary, it’s “chronic low-dose aspirin use can lower overall CVD risk, but does not reduce CVD mortality or all-cause mortality, and you may pay for it with gastrointestinal bleeding, and increased risk of ulcers“.

For a more nuanced explanation, see: Aspirin, CVD Risk, & Potential Counter-Risks

On the other hand, if you are having a heart attack and are waiting for the ambulance that you already called, and have aspirin to hand that you don’t have to go looking for, then it can be good to take a dose then.

For more on that, see: How To Survive A Heart Attack When You’re Alone

There are more problems

In the case of chronic use of low-dose aspirin, not only does it increase the risks of bleeding, especially gastrointestinal bleeding, and ulcers, but also it increases the risk of anemia. Given that anemia also gives the symptom “dizziness”, this is also a significant threat for increasing the incidence of falls in the older population, too, which can of course lead to serious complications and ultimately death.

For the science about this, see: Low-Dose Aspirin & Anemia

Now, about aspirin and cancer metastasis

This one’s a point in aspirin’s favor.

Cancer is, in and of itself, obviously a big problem. In terms of when it’s most likely to kill someone, that is usually when the cancer becomes metastatic, that is to say, it has spread.

So, while preventing cancer and, failing that, killing cancer are very important goals, there is a third axis to cancer care, which is preventing metastasis in someone who has cancer.

And that’s what aspirin does. How, you ask?

Scientists found this one out by accident!

They were doing genetic research in mice, to find genes that had an effect on metastasis. In the process, they found a certain gene that instructs the creation of a certain protein, and mice that lacked that gene (and thus its associated protein) had less metastasis.

The protein in question suppresses T-cells, which are programmed to recognize and kill metastatic cancer cells (amongst having other great jobs; they are an important part of the immune system in general, and one that declines with aging; most people in their 60s or older are producing very few T-cells).

About that, see: Focusing On Health In Our Sixties

Tracing the cell signaling, the researchers found that the protein is activated when T-cells are exposed to thromboxane A2 (or TXA₂ to its friends).

And TXA₂? That’s produced by platelets, and aspirin works by inhibiting TXA₂ production, effectively making platelets (and thus the blood as a whole) less sticky.

So, that’s quite a few steps in the process, but ultimately:

1. Aspirin inhibits TXA₂ production
2. Lower TXA₂ levels mean ARHGEF1 (that’s the protein) isn’t activated
3. ARHGEF1 not being activated means T-cells are free to do their thing
4. T-cells are now free to kill metastatic cancer cells

You can read the paper here:

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

Take care!