Malignant lung tumors may contain not one, not two, but potentially tens of thousands of genetic mutations which, together, contribute to the development of the cancer.

A sample from a lung tumor from a heavy smoker revealed 50,000 mutations, according to a report in the May 27 issue of Nature.

“People in the field have always known that we’re going to end up having to deal with multiple mutations,” said Dr. Hossein Borghaei, director of the Lung and Head and Neck Cancer Risk Assessment Program at Fox Chase Cancer Center in Philadelphia. “This tells us that we’re not just dealing with one cell line that’s gone crazy. We’re dealing with multiple mutations. Every possible pathway that could possibly go wrong is probably found among all these mutations and changes.”