There is a 1/19 chance you will die of lung cancer. That's certainly high enough to take seriously. Lung is the #1 cancer killer.

The NYT just had an article saying half the people diagnosed with lung cancer never see a oncologist, they just die. If they had caught the cancer early 5 year survival is in the high 60s. A Low Dose CT (LDCT)scan will show it easily in early stages. Insist that your doc give you one, or just get one, they cost under $200, get one every year.