Researchers have discovered that using the diabetes drug metformin alongside Avastin (bevacizumab) significantly enhances the treatment's ability to block tumor growth in aggressive skin cancer. The study, published in Cancer Discovery, found that while Avastin alone blocked tumor growth by 34 percent in mice, the combination with metformin increased this suppression to 64 percent.
Interestingly, treatment with metformin alone led to an increase in tumor growth in melanoma cells, the most aggressive form of skin cancer. This was due to metformin causing melanoma cells with a BRAF mutation to secrete VEGF-A, a protein that promotes the formation of new blood vessels in the tumor, thereby accelerating tumor growth. However, when metformin was used in conjunction with drugs like Avastin that inhibit VEGF-A, the combination effectively overcame this resistance, enhancing the effectiveness of VEGF-A inhibitors.
Professor Richard Marais, the lead researcher, highlighted the unexpected synergy between metformin and Avastin, suggesting that this combination could help overcome the resistance skin cancer patients often develop to drugs like Avastin. He also emphasized the need for further research to understand metformin's impact on BRAF melanomas and whether its prescription could potentially worsen the disease.
This research builds on previous findings that metformin possesses anticancer properties and explores its effects on melanoma cells with BRAF and NRAS mutations, the two most common genetic mutations in melanoma. With around 11,800 people diagnosed with melanoma annually in the UK, and approximately half of these cases involving BRAF mutations, the study's findings could lead to more effective treatment strategies for this aggressive form of skin cancer.
Dr. Lesley Walker from Cancer Research UK noted the potential of this drug combination to treat aggressive skin cancer more effectively and stressed the importance of clinical trials to confirm these benefits in patients. The research, funded by Cancer Research UK, the Association of International Cancer Research, and conducted at The Institute of Cancer Research, represents a significant step forward in the fight against skin cancer, offering hope for more effective treatments in the future.
