A new study shows 4 in 10 cancer deaths are attributable to cigarette smoking in parts of the South region and Appalachia. For this study, appearing in Cancer Causes & Control, Farhad Islami, MD, Ph.D., and colleagues at the American Cancer Society examined the proportion of cancer deaths from 2013 to 2017 attributed to cigarette smoking in 152 metropolitan and micropolitan statistical areas (MMSAs).