Smoking causes most cases of lung cancer. The risk depends upon the number of cigarettes smoked every day and for how long someone has smoked. Being around the smoke from others (secondhand smoke) also raises your risk for lung cancer. However, some people who do not smoke and have never smoked have developed lung cancer.
A review of decades of research has recently shown that smoking marijuana may help cancer cells grow, but there is no direct link between the drug and developing lung cancer.
High levels of air pollution and drinking water containing high levels of arsenic can increase your risk for lung cancer. Radiation therapy to the lungs can also increase the risk.
Working with or near the following cancer-causing chemicals or materials can also increase your risk:
Asbestos
Products using chloride and formaldehyde
Certain alloys, paints, pigments, and preservatives
Cancer Term:(malignant neoplasm) is a class of diseases in which a group of cells display uncontrolled growth, invasion that intrudes upon and destroys adjacent tissues, and sometimes metastasis, or spreading to other locations in the body via lymph or blood. These three malignant properties of cancers differentiate them from benign tumors, which do not invade or metastasize. Cancer-ar-foundation
