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A new estimate says anti-smoking measures have saved roughly 8 million U.S. lives since a landmark 1964 report linking smoking and disease.  Yet the nation's top disease detective says many other countries do a better job at trying to cut tobacco use. 

The reports appear online Tuesday in the Journal of the American Medical Association. This week's journal marks the 50th anniversary of a surgeon general report credited with raising health alarms about smoking. 

More than 42 percent of U.S. adults smoked in years preceding the report; that rate has dropped to about 18 percent. 

Smoking remains a stubborn problem and has been linked with heart disease, cancer, lung ailments and stroke. Those are the nation's top four leading causes of death.  (Associated Press)