A pill long used around the world to treat dry mouth could help protect against lung cancer in lifelong smokers. The drug appears especially promising for former smokers, who still face a higher-than-usual risk of lung cancers years after they quit. The preliminary study found that the medicine reduced the risk of new or worsening precancerous growths in the lungs of longtime smokers by about 30% during 7 months of use.
The drug, made by the French company Solvay Pharma, is not available in the US. It is sold in Canada, Europe, China and other countries as Sialor or Sulfarlem and has been on the market for 30 years. The drug appears to work by increasing the body's levels of an enzyme called Gst that ordinarily detoxifies dangerous substances, such as tobacco smoke. Levels of this enzyme can be abnormally low in people long exposed to tobacco.
Experts say large-scale testing will be necessary to show that the approach truly lowers the risk of lung cancer, but they say the latest findings make biological sense. "It's an intriguing, promising finding in a small patient population. When people give up smoking, they retain a substantial risk of lung cancer. Half of newly diagnosed lung cancer is in former smokers. The challenge is helping these people lower their risk." said Dr. Frank J. Rauscher III of the Wistar Institute in Philadelphia.