Clayton, N.C. — Lung cancer is the second-most commonly diagnosed cancer in both men and women, and it is still the most common cause of cancer death, according to the American Lung Association.

Duke researchers said they believe they've found one reason why some lung cancer patients fight the disease better than others.

After Paul and Shirley Adams were married in 1984, they had a long-range goal of building a home on a lake. Then, in 1999, Paul Adams was diagnosed with Stage 4 non-small cell lung cancer. He died three months later on April 15 at age 62.

“I was just stunned, you know?” said Shirley Adams. “Last year, I was diagnosed on April 15. How ironic, yeah?”

Shirley Adams had Stage 3A lung cancer, but she responded well to treatment. The fact that women with lung cancer typically fare better than men isn't news, but now Duke researchers believe they know why.

“(Women’s) biology of their disease is less complex than men,” said Duke Oncologist Dr. Anil Potti.

Potti is the lead author of a study that also shows younger patients' lung cancer tends to be genetically less complex than in older patients. Elderly patients are often passed over for clinical trials and aggressive treatment.

“We've actually shown that there are several cohorts of patients about the age of 70 who actually have disease that can be targeted and be treated effectively,” Potti said.

The findings might help doctors take a patient's age and sex into account in planning a treatment strategy. At age 56, Shirley Adams is thankful her treatment has been successful.

“I've had two more PET scans since then, and they have come back cancer-free,” she said.

The Duke study was published in the Journal of the American Medical Association.