Somatic alterations in lung cancer: Do environmental factors matter?

Lung cancer is the leading cause of cancer-related death worldwide and smoking tobacco is now definitively established as the dominant risk factor for the malignancy. However, lung cancer can and does occur in never smokers, thus illustrating the existence of other risk factors. Many of these latter are environmental, such as workplace and home carcinogens, air pollution, radon and certain infectious agents. One of the most remarkable advances in thoracic oncology is the recent identification of somatic oncogenic molecular abnormalities, some of which are candidates for targeted therapies. Active smoking is now known to cause a particular somatic profile distinct from that found in never-smokers. This has logically led researchers to consider the possibility that exposure to other lung cancer risk factors may also engender a unique somatic profile. Thus, with the present work, we sought to review current knowledge on somatic profiles in the setting of bronchial cancer (for targetable mutations such as EGFR, ALK, BRAF and HER2, as well as some non-targetable mutations such as TP53, and KRAS) and their associations with environmental risk factors for the malignancy.