Scientists have unfolded significant insights on how aspirin might reduce the metastasis of various cancers through immune system stimulation, as documented in groundbreaking research from the University of Cambridge. This study, led by Professor Rahul Roychoudhuri and published on March 5, 2025, highlights the exciting potential of aspirin to change the cancer treatment paradigm.
This study, primarily funded by the Medical Research Council, builds upon existing observations of patients with cancer who were taking daily low-dose aspirin. Previous studies suggested these patients experienced reduced metastasis rates in cancers such as breast, bowel, and prostate cancers. Yet, the precise mechanisms remained elusive until now.
The researchers were examining how cancers metastasize—spread from their primary site—when they discovered the role of the protein ARHGEF1. It was found to play a pivotal role: mice lacking this gene showed significantly lower metastasis to the lungs and liver compared to their counterparts, indicating ARHGEF1 suppresses T cells, immune cells capable of recognizing and eliminating rogue cancer cells.
Dr. Jie Yang, one of the key researchers, expressed her excitement over this finding. "It was a Eureka moment when we found TXA2 was the molecular signal... which suppresses T cells, highlighting aspirin's dual role as both an anti-clotting agent and now as potentially effective against cancer metastasis," she stated.
The discovery of thromboxane A2 (TXA2)—a molecule associated with blood clotting—uncovered how it contributes to cancer metastasis. Aspirin works by inhibiting TXA2 production, which not only aids its well-known anti-clotting effects but also releases T cells from suppression, thereby empowering the immune response against metastatic cells.
The researchers leveraged mouse models of melanoma to demonstrate aspirin's efficacy; those mice exhibited reduced frequencies of metastases when administered aspirin compared to control groups.
Professor Roychoudhuri noted the broader impact of their findings: "Despite advances in cancer treatment, many patients with early-stage cancers receive treatments such as surgical removal of the tumor. Yet, they often relapse due to the eventual growth of micrometastases – cancer cells seeded elsewhere but remaining dormant. This research might enable the development of therapies targeting these early vulnerable phases effectively."
The study posits the existence of unique therapeutic opportunities during these early stages of cancer spread and emphasizes the importance of timely intervention. Roychoudhuri added, "Most immunotherapies are typically developed for already established metastatic cancer. We believe targeting this initial phase can be pivotal to preventing recurrence."
Future clinical trials will investigate how best to utilize aspirin following cancer diagnosis, collaborating with Professor Ruth Langley from the MRC Clinical Trials Unit at University College London, who is leading the Add-Aspirin trial.
Langley, who was not part of the research but commented on its significance, stated, "This is an important discovery. It will enable us to interpret the results of clinical trials and determine which patients are most likely to benefit from aspirin post-cancer diagnosis." She stressed the necessity of consulting with healthcare professionals, as aspirin isn't without risk; it can cause serious side effects, including bleeding or stomach ulcers, making careful patient selection imperative.
Given the results from this study and subsequent clinical trials, researchers believe aspirin and similar drugs could be less expensive and more accessible alternatives to antibody-based therapies, especially valuable for wider populations.
The research was primarily supported by funding from the Medical Research Council, with additional assistance from the Wellcome Trust and the European Research Council, showing the collaboration's significance across multiple institutions. The Add-Aspirin clinical trial is also backed by major organizations including Cancer Research UK and the National Institute for Health and Care Research.
With the scientific community continuously probing the vast mechanisms behind cancer metastasis, this new study opens avenues not only for potential treatments but for accessible solutions worldwide, extending the hope for millions affected by cancer.