Lung cancer -- linked to smoking 90% of the time -- is the top cause of cancer deaths in the U.S. in men and women alike. Smoking also makes a lot of other cancers more likely, including cancers of the mouth, kidney, liver, bladder, pancreas, stomach, colon, and rectum. And it’s a major cause of COPD (chronic obstructive pulmonary disease), a group of diseases that damage the tiny air sacs in the lungs.