Smoking Causes Half of All Deaths from 12 Cancers, Estimate Shows:

The analysis, published in JAMA Internal Medicine, was written by Rebecca Siegel of the American Cancer Society in Atlanta, GA, and coauthors.

The new data are relevant, they say, because estimates are out of date since the 2014 US Surgeon General's report, which covered "cancer overall and lung cancer specifically but not separately for the 11 other cancers found to be caused by smoking."

Further, smoking patterns have changed. For example, while the level of smoking fell from 23.2% in 2000 to 18.1% in 2012, the authors cite evidence to suggest the risk of cancer death among smokers can rise over time.

The data used by the authors came from results of the 2011 National Health Interview Survey, the Cancer Prevention Study II, and a study known as the pooled contemporary cohort by Thun and coauthors.

The analysis estimates that 167,805 deaths - out of a total of 345,962 from the 12 cancers - were attributable to smoking cigarettes.

Other results of the research include:

• Respiratory cancers - of the lung, bronchus and trachea - attributed for most smoking-related deaths (125,799)
• Voice box cancers related to smoking accounted for 2,856 deaths, which were 76.6% of all larynx cases
• About half of the deaths from cancers of the oral cavity, esophagus and urinary bladder were attributable to smoking.

The study's estimates may not be fully representative because its populations were less racially diverse and more educated than the American population at large, and the analysis excluded tobacco exposure from sources other than cigarettes, including from second-hand smoke.

The new study has included two cancers previously left out of estimates because of their more recent links to smoking - colorectal and liver cancers.