A drug used to treat seizures, migraines and mood disorders may prevent head and neck cancer, researchers reported on Monday.
The drug, called valproic acid, is already being tested as a possible treatment for several cancers. But a new study shows that veterans who were taking the drug to treat headaches, seizures, PTSD or other ailments had a 34 percent lower-than-average risk of developing head and neck cancer.
The effects were clearest in smokers, a finding that suggests the drug may reverse some of the damage caused by cigarette smoke.
“A 34 percent risk reduction for the development of head and neck cancer with valproic acid use could result in the prevention of up to approximately 16,000 new cases and 3,000 to 4,000 annual deaths in the U.S. alone,” said Dr. Johann Christoph Brandes of the Atlanta Veterans Affairs Medical Center and Emory University in Atlanta.
“Head and neck cancer is an important global health crisis, and low cost and low-toxicity prevention strategies like valproic acid use have a high potential impact on pain, suffering, costs, and mortality associated with this disease,” added Brandes, who led the study.
The team at the VA studied the records of 439,628 patients. About 27,000 of them had taken valproic acid — sold under brand names such as Depakote, Epilim and Valpro — for at least a year. They were followed for an average of four years.
Researchers were looking at valproic acid because other studies have shown it can affect tumors, by acting on the changes in the DNA that drive some cancers. The drug is being studied as a possible treatment for some cancers, including head and neck cancer.
There were no effects on the rates of lung cancer, prostate cancer, colon cancer or several other cancers. But the veterans who took valproic acid for three years or more were very much less likely to be diagnosed with head and neck cancer. The more valproic acid was in their system, the lower their risk of the cancer.
Head and neck cancer can be caused by smoking and alcohol use and by the human papillomavirus, also known as HPV. But rates of the types of head and neck cancers most commonly caused by HPV did not seem to be affected by the drug.
About 40,000 Americans are diagnosed with head and neck cancer — which includes cancer of the mouth, throat and tongue — every year, and about 10,000 die from it.