Women who have never smoked are no more likely to die from lung cancer than male non-smokers - despite conventional wisdom otherwise, U.S. researchers reported on Tuesday.

In fact, men who never smoked had higher lung cancer death rates than female lifelong non-smokers, the study of nearly a million Americans found.

“Our findings, paradoxically, are compatible with the clinical perception that women outnumber men among lung cancer patients who never smoked,” said Dr. Michael Thun of the American Cancer Society, who led the study.

“But the reason appears to be unrelated to cancer risk,” Thun added in a statement.

“Instead, it appears to be the result of the fact that there are far more women than men over the age of 60 who never smoked. Census data show there are about 16.2 million women compared to just 6.4 million men in the U.S. who are over 60 and never smoked.”

The lung cancer death in March of Dana Reeve, a non-smoker and widow of “Superman” star Christopher Reeve, focused attention on the small but significant risk that non-smokers have from lung cancer.

Between 80 and 90 percent of the 174,470 new cases of lung cancer that will be diagnosed in the United States in 2006 are caused by smoking.

Lung cancer is by far the biggest cancer killer in the world, and it will kill 162,460 people this year in the United States alone.

An estimated 15,000 lifelong non-smokers die of lung cancer every year in the United States, with causes including secondhand smoke, asbestos exposure and radon gas.

Writing in the Journal of the National Cancer Institute, the researchers said they found that men overall still have a significantly higher risk of dying from lung cancer than women do, mostly because men have historically been more likely to smoke.

“Our findings are reassuring for women who’ve never smoked and who may have been alarmed by recent reports indicating their risk was higher than it actually is,” said Thun.