A doctor at Stamford Health says he is seeing more cases of women with lung cancer.

The women have been leading healthy lives and have never smoked, including Lauren Corcoran, from Stamford.

After the birth of her first child, she was training for a half marathon about a year ago.

"We were going to have a year of health and finally focus on getting back in shape,” said Corcoran.

That's when she got some shocking news.

Corcoran injured her neck and when she went in for a scan, doctors found a sizable mass in one of her lungs that turned out to be Stage 3 lung cancer.

"So to go from you know a very blessed healthy life to all of the sudden you know an unknown tumor in my chest was paralyzing to be honest. And no history of cancer in my family or anything like that," said Corcoran.

Dr. Michael Ebright, the director of thoracic surgery at Stamford Health, says patients like Corcoran in their 30s and 40s that show no damage to their lungs have a gene mutation called EGFR that leads to non-small cell lung cancer.

Doctors are still studying why.

"Maybe hormonally driven. Estrogen actually plays a big role in lung development and we think estrogen may have a role to play," said Ebright.

Doctors removed half of Corcoran's left lung.

"I'm still getting my lung capacity back to where it was," said Corcoran.

She is now cancer free, and will continue a regimen of treatments for the next few years.

Ebright says he knows why Corcoran had such a successful outcome.

"I believe that her daughter was the best medicine she could have," said Ebright.

Corcoran and her husband are still hoping they can have another child.