Could sildenafil(Viagra) Help Stop Cancer From Spreading? New Study Finds

A medicine best known for treating erectile dysfunction could one day help fight one of cancer's deadliest features, its ability to spread to other parts of the body. Scientists have found promising evidence that sildenafil, the active ingredient in Viagra, may interfere with the process of cancer metastasis, opening the door to a possible new use for the decades-old drug.

Metastasis is the process by which cancer cells break away from the original tumour, travel through the body and establish new tumours in distant organs. It is responsible for most cancer-related deaths, making it one of the biggest challenges in cancer treatment.

In the new study published in the journal ‘Cancer Research’, researchers discovered that sildenafil disrupts the way cancer cells use cholesterol, a substance they rely on to build cell membranes and spread to other tissues. By limiting cancer cells' access to cholesterol, the drug appeared to make it harder for them to migrate and form new tumours.

What Did Researchers Find

The scientists found that sildenafil works by blocking an enzyme called phosphodiesterase type 5 (PDE5). This increases the levels of a signalling molecule known as cGMP, which not only improves blood flow, the reason Viagra is used to treat erectile dysfunction, but also interferes with a protein that transports cholesterol inside cells. As a result, cancer cells may struggle to obtain the cholesterol they need to spread.

The research combined laboratory experiments using cancer cells and mouse models with an analysis of more than 20 years of anonymised health records from around five million people.

Researchers also studied about 40,000 men diagnosed with cancer. They found that men who had taken sildenafil before their cancer diagnosis had better overall survival than those who had not. The benefit appeared to be even greater among people who had also taken statins, medicines commonly used to lower cholesterol.

While the findings are encouraging, experts stress that the research does not prove Viagra can treat or prevent cancer. Much of the biological evidence comes from laboratory and animal studies, and the analysis of patient records only shows an association rather than proving that sildenafil directly improves survival. Clinical trials are still needed to confirm whether the drug is safe and effective as part of cancer treatment.

Researchers also say it is too early to know whether sildenafil would work equally well against all types of cancer or whether similar benefits would be seen in women, as the available patient data mainly involved men who had been prescribed the medicine.

Note: For now, doctors advise patients not to self-medicate or start taking Viagra in the hope of preventing cancer spread. However, because sildenafil is already a widely used and well-studied medicine, scientists believe it could be an attractive candidate for future cancer therapies if larger human studies confirm these early findings.