2 Smoking
One study conducted by researchers from the American Cancer Society found that 48.5 percent of all deaths in 2011 from 12 different cancer types combined could be attributed to cigarette smoking. Such cancers include lung—the researchers found that a staggering 80.2 percent of all cases were related to smoking—liver, esophagus, and stomach. And for other less obvious ways you might be putting yourself at risk, check out the 20 Surprising Habits That Increase Your Cancer Risk.
