The number of new lung cancer cases in the U.S. dropped among men in 35 states and among women in 6 states between 1999 and 2008, according to a new report by the Centers for Disease Control and Prevention (CDC). The decrease in women came after a decades-long upward trend.

The decrease in lung cancer cases corresponds closely with smoking patterns across the nation. In the west, where smoking prevalence is lower among men and women than in other regions, lung cancer incidence is decreasing faster. Studies show declines in lung cancer rates can be seen as soon as five years after smoking rates decline.

The report also noted that states that make greater investments in effective tobacco control strategies see larger reductions in smoking; and the longer they invest, the greater the savings in smoking–related health care costs. Such strategies include higher tobacco prices, hard–hitting media campaigns, 100 percent smoke-free policies, and easily accessible quitting treatments and services for those who want to quit.

“Although lung cancer among men and women has decreased over the past few years,” said CDC Director Thomas R. Frieden, M.D., M.P.H., “too many people continue to get sick and die from lung cancers, most of which are caused by smoking.  The more we invest in proven tobacco control efforts, the fewer people will die from lung cancer.”

Lung cancer is the most commonly diagnosed cancer, and the leading cause of cancer death in the United States. Cigarette smoking and exposure to secondhand smoke cause most lung cancer deaths in the United States. To further reduce lung cancer incidence, intensified efforts to reduce smoking are needed.

For this report, researchers analyzed lung cancer data from CDC′s National Program of Cancer Registries and the National Cancer Institute′s Surveillance, Epidemiology, and End Results Program. They estimated smoking behavior by state using the CDC′s Behavioral Risk Factor Surveillance System.

Study findings include:

The study is published in the CDC′s Morbidity and Mortality Weekly Report.