The health case against cigarette smoking continues to get stronger as research shows the habit’s link to cancers besides lung cancer.
A study published today in the journal JAMA Internal Medicine found that 48.5 percent of the nearly 346,000 cancer deaths in 2011 were caused by cigarette smoking. During that year, smoking caused 12 types of cancers in adults over the age of 35.
According to the study, 167,805 deaths were attributed to cigarette smoking. Lung, bronchus, and trachea cancers accounted for 125,799 deaths, while larynx cancer was linked to 2,856 deaths. About half of the cancer deaths of the oral cavity, esophagus, and urinary bladder were linked to smoking.
The analysis did not address tobacco exposure other than cigarettes. The authors also noted that study populations were less racially diverse and more educated than the overall U.S. population.
Smoking causes the overwhelming majority of lung cancer deaths, along with half of the deaths from oral cavity cancer, esophageal cancer, and bladder cancer.
The new study shows that smoking also drove nearly 10,000 deaths from cancers less commonly linked to it, including colon cancer and liver and intrahepatic bile duct cancers.
The death toll is especially striking in light of the fact that smoking continues to decline in popularity.
“Cigarette smoking continues to cause numerous deaths from multiple cancers despite half a century of decreasing prevalence,” the study said.
Rebecca L. Siegel, a researcher with the American Cancer Society and an author of the paper, noted that smoking prevalence went down from 23.2 percent in 2000 to 18.1 percent in 2012.
Can We Lower the Numbers?
Death from smoking is 100 percent preventable, Siegel insisted.
“Although we’ve had 50 years of reductions in smoking prevalence, still, 170,000 cancer deaths were caused by smoking in 2011,” she said.
Tobacco control efforts need to focus on populations with higher smoking rates in order to reduce those numbers, Siegel said.
For example, 29 percent of poor people smoke while just 16 percent of more affluent groups do. A quarter of gay and lesbian people smoke, compared to 18 percent of straight people. In West Virginia and Kentucky, 27 percent of people smoke compared to 10 percent in Utah and California.
Another recent study helps explain how smoking can trigger so many different cancers. Researchers found that DNA damage from smoking can be detected in cheek swabs. The study provided evidence that smoking causes a mutation found in cancers that aren't usually associated with the habit, such as breast and gynecological cancers. That study was published in JAMA Oncology.