10 % World wide estimate is 10% - due to cigarette smoking and due to use of biofuels - like wood and others. In usa incidence is 16.3 new cases per 1000 per year.
Don't know. Would refer you to our specialists at healthtaps pulmonologist for a correct answer. I have answered your questions before. My practice is in surgery and self-healing meditation to treat cancers and chronic illnesses as a secondary support management of complementary medicine.