PreviewLung cancer, the No. 1 cancer killer of men in the United States and on its way to becoming No. 1 among women, produces telltale changes in the face and mouth. Dr Dreizen and his associates have studied the orofacial manifestations of lung cancer in a large group of patients. They present their findings here as a guide to primary care physicians, who are often in the best position to identify the highly visible, although not pathognomonic, signs.