Diane White had bronchitis off and on for most of her adult life. But one case in late 2019 was hard to shake.

So, she saw her family doctor in Fort Smith, Arkansas, and had an X-ray. The doctor thought it was pneumonia. But after several scans and a biopsy, Diane learned she had non-small cell lung cancer.

Diane was 68 at the time of her lung cancer diagnosis. It was stage...