In a recent review published in Open Biology, researchers discussed the existing evidence on the use of acetylsalicylic acid (aspirin) in the treatment of cancer. They conducted a literature review to understand how aspirin influences the biological mechanisms of cancer and summarized findings from clinical trials and observational studies implicating aspirin in the treatment of cancer.
Study: Aspirin and cancer: biological mechanisms and clinical results. Image credit: fizkes/Shutterstock
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Botanical resources and active plant components have long been a source of potential cancer treatments. The potency of salicylates to regulate biotic and abiotic stress responses and plant defense against various pathogens has been established through years of research.
Given the prevalence of cancer-related deaths, especially in underdeveloped countries with poor access to diagnostic and treatment options, there is a vital need for affordable and accessible cancer therapy. Developing new cancer drugs is expensive and tedious, with clinical trials that may not always be successful. Therefore, the exploration of existing drugs approved for the treatment of cancer is growing.
Acetylsalicylic acid, or aspirin, is an anti-inflammatory and analgesic drug that is commonly used against pain and fever in various diseases. Certain biological mechanisms regulated by aspirin also play a role in cancer initiation and growth, making it a useful cancer therapeutic option.
About the study
In the present study, researchers used a systematic literature review to address three main aspects of aspirin use in cancer therapy. They first summarized current findings on the biological mechanisms by which aspirin may regulate pathogenic pathways at the cellular level and metastatic processes in cancer.
The review then examined several clinical studies to understand the effect of aspirin on cancer metastasis and survival. Finally, the researchers addressed known side effects of aspirin use, such as intracranial and gastrointestinal bleeding, and discussed the safety aspects of aspirin use in cancer therapy.
Main findings
The review reported a multitude of pathways through which aspirin could potentially play a role in cancer therapy. Aspirin’s main mode of action is through the disruption of the cyclooxygenase (COX) enzyme, which inhibits the formation of cancer signaling molecules such as prostanoids. Aspirin also disrupts proliferative and inflammatory pathways and interferes with platelet-driven pro-carcinogenic processes.
Angiogenesis, or the formation of new blood vessels, is an important part of cancer progression. Studies on lymphoma and colon cancer cell lines showed that aspirin prevents angiogenesis by altering the COX enzyme and regulating the activity of vascular endothelial growth factor (VEGF). In addition, aspirin stimulates pro-apoptotic pathways and promotes tumor suppressor gene-mediated deoxyribonucleic acid (DNA) repair.
Metastasis studies using in vivo animal models and in vitro cell lines have shown that platelets play an important role in enabling metastatic migration by secreting growth factors, promoting the formation of metastatic niches and the production of tumor suppressor gene inhibitors. Aspirin showed antiplatelet activity, which reduced metastasis in many animal models in vivo. Research using proteomics and gene-environment interactions also provided evidence of aspirin down-regulating the expression of DNA repair genes, the overexpression of which has been linked to an increased risk of colon cancer. colon
The overall evidence from clinical and observational studies is favorable for the use of aspirin in cancer therapy, despite high heterogeneity. However, the authors highlighted the absence of ad hoc randomized trials exploring the effect of aspirin in a wide range of cancers. Most of the evidence comes from meta-analyses of observational data from individuals with different types of cancer, a quarter of whom were taking aspirin.
According to the authors, many studies have focused on common cancers such as lung, breast, prostate and colon, which account for only 30% of cancer cases worldwide, leaving the rarer forms of cancer unstudied. cancer
Aspirin use has also been linked to increased gastrointestinal and cerebral bleeding due to its antiplatelet activity. Although many studies reported fatal bleeding related to aspirin use, especially in elderly patients, one interpretation of the results also suggests that the antiplatelet action of aspirin is uncovering existing gastrointestinal pathologies, such as gastric lesions, which can then be treated.
Conclusions
Overall, the study indicates that aspirin’s role in regulating several metabolic pathways makes it a potentially valuable and viable cancer treatment option. However, most of the current evidence for its effectiveness in reducing tumor cell proliferation and metastasis comes from four ad hoc randomized trials. Therefore, more research is needed on the use of aspirin in the treatment of some of the rarer forms of cancer. Extensive research into the adverse effects of aspirin is also needed before promoting the use of aspirin in cancer therapy.