How important is lung cancer as a public health issue?
Lung cancer is the most common cause of cancer-related death in men and women, and it is the second most common cause of cancer after prostate cancer in men and breast cancer in women. Tobacco use is the top risk factor for lung cancer, and 85% of lung cancer deaths are due to smoking. The risk of developing lung cancer is proportional to the number of pack-years of smoking. Synchronous primary lung cancers occur in <5% of patients with lung cancer, but metachronous primary lung cancers may occur in 15%, with a latency of about 4 to 5 years. Overall, survival rates for patients with lung cancer are poor (<15% at 5 years), although patients with treated early-stage disease or with AIS or MIA tumor subtypes tend to have much better survival.