New research shows that a common mood-stabilizing drug may help reduce the risk of head and neck cancer, illuminating a potential prevention strategy against a group of diseases that cause thousands of deaths each year.

Dr. Johann Christoph Brandes, a researcher with the Atlanta Veterans Affairs Medical Center and lead author of the new study, said the results show that the mood stabilizer and anticonvulsant valproic acid (VPA) may one day become a cost-effective alternative for doctors treating cancers of the larynx, oral cavity, or salivary glands.

"Head and neck cancer is an important global health crisis,” he said in a press release. “Low cost and low toxicity prevention strategies like VPA use have a high potential impact on pain, suffering, costs, and mortality associated with this disease."

Though traditionally used to treat epilepsy, bipolar disorder, and migraine headaches, VPA has of late become a focal point for cancer research, as it inhibits so-called histone acetyl transferases — a process that otherwise helps cancerous cells stay alive. Brandes’ study, which is published in the journal Cancer, sought to investigate this by examining disease rates among veterans taking VPA.

The researchers used a sample of 439,628 participants, of whom 26,911 were taking the medication for complications like seizures and post-traumatic stress disorder. They found that, compared to non-VPA veterans, veterans who had taken the medication for at least a year had a 34 percent lower risk of developing head and neck cancers. Higher doses and longer duration of use appeared to boost this protective effect further.

According to Brandes, this means that VPA could have a tremendous impact on incidence and mortality rates. "A 34 percent risk reduction for the development of head and neck cancer with VPA use could result in the prevention of up to approximately 16,000 new cases and 3,000 to 4,000 annual deaths in the US alone," he explained.

Cancers known collectively as head and neck cancer typically originate in so-called squamous cells that line mucus-covered surfaces inside the mouth, nose, and throat. The National Cancer Institute estimates that about 52,000 U.S. men and women are diagnosed with these cancers each year. Risk factors include alcohol consumption, smoking, and use of chewing tobacco.