Aspirin can prevent some cancers from spreading, study finds

Despite advances in cancer treatment, many early-stage patients experience a recurrence when dormant cancer cells spread and grow into metastatic tumors.

Scientists have now identified how aspirin might help prevent this deadly progression by stimulating the immune system, offering new hope for reducing metastasis rates in cancers like breast, bowel, and prostate.

Cancer starts as a localized tumor, but 90% of cancer-related deaths occur when it spreads to other organs. Individual cancer cells that detach from the original tumor and travel through the bloodstream are highly vulnerable to immune system attack. However, once these micrometastases establish themselves in new tissues, they develop protective mechanisms that shield them from immune destruction. Understanding how the immune system interacts with these early-stage metastatic cells has been a key focus for researchers.

Aspirin, a widely used anti-inflammatory drug, is known for its ability to inhibit cyclooxygenase (COX) enzymes. Previous studies suggested that daily low-dose aspirin reduces the spread of certain cancers, but the mechanism remained unclear.

A recent study led by researchers at the University of Cambridge has now revealed a crucial immune-suppressing pathway that aspirin disrupts, shedding light on its anti-metastatic effects.

The research team discovered that platelets, small blood cells responsible for clotting, produce a molecule called thromboxane A2 (TXA2). This molecule activates an immune-suppressing pathway within T cells by signaling through a protein known as ARHGEF1. When T cells are exposed to TXA2, their ability to attack and destroy metastatic cancer cells is suppressed.

By blocking TXA2 production, aspirin effectively lifts this suppression, restoring T cells' capacity to eliminate cancer cells before they establish metastatic tumors.

The study, published in Nature, demonstrated that in mice with melanoma, those given aspirin had significantly fewer metastatic tumors than untreated mice. The reduction in metastases was directly linked to aspirin's ability to prevent TXA2 from impairing T cell function.

Professor Rahul Roychoudhuri, the study’s lead researcher, explained: “Despite advances in cancer treatment, many patients with early-stage cancers undergo curative treatments like surgery, only to relapse due to micrometastases. We have identified a unique therapeutic window when cancer cells are especially vulnerable to immune attack. Targeting this window could prevent recurrence and dramatically improve outcomes.”

The breakthrough was unexpected. Researchers initially screened 810 genes in mice and identified 15 that influenced metastasis. One of these genes produced ARHGEF1, a protein that dampens T cell activity.

The team found that mice lacking this gene experienced significantly lower rates of metastasis in the lungs and liver. Further investigation revealed that ARHGEF1 is activated by TXA2, linking it to aspirin’s known effects.

Dr. Jie Yang, who led much of the experimental work, described the moment of discovery: “It was a Eureka moment when we found TXA2 was the molecular signal that activates this suppressive effect on T cells. We had not anticipated this connection and it took our research in a completely new direction.”

This discovery not only explains aspirin’s ability to reduce metastasis but also opens doors to developing new drugs that specifically target the TXA2-ARHGEF1 pathway. Such treatments could potentially be more effective and widely accessible than costly antibody-based therapies currently used in immunotherapy.

Ongoing clinical trials are testing aspirin’s role in cancer prevention and treatment. The Add-Aspirin trial, led by Professor Ruth Langley at University College London, is investigating whether aspirin can delay or stop early-stage cancers from returning. While aspirin has promising benefits, it is not without risks. In some individuals, it can cause serious side effects, such as bleeding or stomach ulcers.

Professor Langley, who was not involved in the study, emphasized the importance of a personalized approach: “This is an important discovery that could help us determine who is most likely to benefit from aspirin after a cancer diagnosis. However, aspirin isn’t suitable for everyone, so patients should consult their doctors before taking it.”

The findings have significant implications for future cancer treatments. If further trials confirm aspirin’s benefits, it could become an affordable, widely available tool to reduce cancer recurrence. More research is needed to refine the use of aspirin and develop safer alternatives that target the same pathway without its associated risks.

By uncovering how aspirin enhances the immune system’s ability to fight metastatic cancer cells, scientists have provided a new avenue for preventing cancer’s spread.

This research not only deepens our understanding of cancer metastasis but also highlights the potential of repurposing common medications to improve survival rates in cancer patients.

Note: Materials provided above by The Brighter Side of News. Content may be edited for style and length.

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