(NBC News) – Researchers at Northwestern Medicine found that 65% of their lung cancer patients weren’t eligible for screening. They were more likely to be female, Asian American or nonsmokers.

The current guidelines, from the U.S. Preventive Services Task Force, say that people ages 50 to 80 who smoked a pack a day for 20 years and still smoke or have quit in the past 15 years should get a yearly scan to screen for lung cancer.

But up to 20% of lung cancer cases are diagnosed in people who never smoked or used any other form of tobacco, according to the American Cancer Society.

A new study, published Thursday in JAMA Network Open, suggests that the guidelines are missing the majority of lung cancer cases. (Read More)