Viagra has been known for nearly three decades as one of the most common medications in the world for treating erectile dysfunction, but a new Israeli study points to a surprising possibility: It is possible that the active ingredient in the drug may in the future also assist in the fight against the spread of cancer.
In a study published in the scientific journal Cancer Research, researchers from the Weizmann Institute of Science found that sildenafil, the active ingredient in Viagra, may limit the ability of cancer cells to metastasize through a biological mechanism that was previously unknown.
The study was conducted in the laboratory of Prof. Ayelet Erez, led by Dr. Yarden Ariav, and examined how sildenafil affects the metabolism of cancer cells. According to them, the results may open a new research direction for developing treatments that will impair the ability of cancerous tumors to spread to additional organs.
What is the connection between Viagra and cholesterol?
Cholesterol is known mainly in the context of heart and vascular diseases, but inside the cell it plays another important role. It constitutes a key component in the cell membrane and is particularly necessary for cancer cells that are in the process of detaching from the primary tumor, migrating in the body and establishing themselves in new tissues.
The researchers discovered that sildenafil does not only affect the dilation of blood vessels, as was known until now, but also changes the way cholesterol is transported inside the cell.
According to them, the drug causes the amount of cholesterol available to cancer cells to decrease. As a result, the cells struggle to make the changes necessary for them to metastasize.
This is a new biological pathway that was previously unknown, and it expands scientific understanding regarding the activity of the drug.
Combination with statins may enhance the effect
Another finding that stood out in the study is the possibility of combining sildenafil with drugs from the statin family, which are used to reduce cholesterol levels.
While statins reduce cholesterol production in the body, sildenafil reduces the availability of cholesterol inside the cell. The researchers believe that the combination of the two mechanisms may make it even harder for cancer cells to use the cholesterol they need in order to metastasize.
However, at this stage, this is a research hypothesis that will need to be examined in clinical trials in humans.
Clalit data also pointed to a connection
In order to test whether the findings also have expression in the real world, the researchers integrated into the study an analysis of a large database from Clalit Health Services, which includes information collected over approximately 20 years from about 5 million insured individuals.
The analysis showed a statistical connection between the use of sildenafil and better survival among cancer patients, with the connection being particularly prominent among patients who also took statins.
However, the researchers emphasize that this is an observational study, and therefore it cannot be inferred from it that the drug is what caused the improvement in survival. It is possible that additional factors influenced the results.
The findings are based on experiments in mice, human cancer cell cultures, and the analysis of medical databases. Although they are intriguing, they do not constitute proof that Viagra is effective as a treatment against cancer in humans.
In order to examine whether the drug can indeed reduce the formation of metastases or improve patient survival, controlled clinical trials will need to be conducted.
According to Prof. Ayelet Erez, the study emphasizes that cancer biology is influenced not only by the mutations in tumor cells, but also by the patient's metabolic state and the drugs they take for other diseases. According to her, a broad view of the patient's overall condition may assist in the future in tailoring more effective treatments.
If the findings are confirmed in clinical trials as well, it is possible that in the future an established and familiar drug like Viagra will receive an entirely new role – as part of the fight against the spread of one of the leading causes of cancer mortality.