Cigarette smoking causes about three in 10 cancer deaths in the United States, according to a new study by researchers at the American Cancer Society.
The estimate does not include deaths from secondhand smoke.
The researchers also excluded deaths due to other types of tobacco including cigars, pipes and smokeless tobacco, HealthDay reports.
The findings are published in Annals of Epidemiology.
The study is the first in more than 30 years to estimate the percentage of cancer deaths in the United States that are due to smoking, the researchers said. The previous study also found 30 percent of U.S. cancer deaths were caused by smoking. Since then, smoking rates have dropped, but new cancers have been added to the list of those established as caused by smoking, the researchers said. In addition, lung cancer death rates among female smokers have risen.
"Our results indicate that cigarette smoking causes about three in 10 cancer deaths in the contemporary United States," the researchers wrote. "Reducing smoking prevalence as rapidly as possible should be a top priority for U.S. public health efforts to prevent future cancer deaths."
Fewer American adults are smoking than ever before, according to a recent report by the Centers for Disease Control and Prevention (CDC).
The dip in the smoking rate is due to higher cigarette prices, smoke-free policies and campaigns to combat smoking, the CDC said. Increased access to medications and programs that help smokers quit have also contributed to the lower smoking rate.
Last year about 17.8 percent of American adults smoked cigarettes, down from 20.9 percent in 2005. In 1965, when the government began to track smoking rates, 42.2 percent of adults smoked. While the decline in smoking rates is encouraging, it is not enough to meet the federal goal of reducing the adult rate to 12 percent by 2020, the CDC noted.