Lung cancer in 'Never-smokers': molecular factors trump risk factors.

While they represent a minority of patients with lung cancer, more than 20,000 people in the United States who never smoked cigarettes are diagnosed with lung cancer each year.[1] This makes lung cancer in “never-smokers” one of the 10 most common cancers—more common than ovarian cancer. In this issue of ONCOLOGY, Subramanian and Govindan give an overview of emerging data about lung cancer in never-smokers.[2] The data outlined in this review provide support for the hypothesis that we can define this collection of diseases affecting never-smokers not by the absence of a common risk factor (smoking) but by each tumor’s molecular features.