BOSTON -- Which cancer kills more Americans than any other? The answer is lung cancer, and if you're surprised you're in good company.

NewsCenter 5's Heather Unruh profiled a local woman in the hopes of shinning a light on the growing epidemic.

Lung Cancer May Be Growing Epidemic Among Women

No one was more surprised than Diane Legg when her doctor said the words.

"Lung cancer. I never thought I would hear that," Legg said.

For the 42-year-old mother, who does not smoke, the diagnosis just didn't make sense.

"I didn't think young women got lung cancer," Legg said.

But they do. This year 100,000 American women will be diagnosed with lung cancer and 71,000 will die. The disease claims more women's lives than breast, ovarian and uterine cancers combined, and it doesn't discriminate. Sixty percent of those diagnosed don't smoke.

"The surgeon general said a number of years ago that this is a silent epidemic among women," Legg said.

The vast majority of lung cancer victims don't survive, and for those who do the stigma makes them reluctant to talk.

"Nobody deserves to get cancer -- whether you smoked or not," Dr. Pasi Janne said.

Janne said cigarettes aren't the only cause. There's asbestos and radon exposure.

"Certainly, second-hand smoke is a cause of lung cancer, and then I would say there are a number of causes that we don't know yet," Janne said.

For Legg, the cause is as much a mystery as her unlikely Stage 1 diagnosis.

"I was lucky," she said.

If she hadn't pulled a back muscle lifting her youngest son four years ago, she wouldn't have had a CT scan until it was too late.

Now, she gets scanned every few months.

"It's an anxious time," she said. "My nerves get just as uptight as before."

But for a different reason -- her cancer is back. Her cancer has a genetic mutation. She'll get a targeted treatment -- a pill -- better than chemotherapy.

"If and when we have to do therapy, we know exactly where to go and what drug we'll take and what drug will be effective," Janne said.