“People with an increased risk of lung cancer may consider annual lung cancer screening using low-dose CT scans. Lung cancer screening is generally offered to older adults who have smoked heavily for many years or who have quit in the past 15 years.  If there’s reason to think that you may have lung cancer, your doctor can order a number of tests to look for cancerous cells and to rule out other conditions.  An X-ray image of your lungs, a sample of abnormal cells may be removed in a procedure called a biopsy, and doing the staging of the cancer.”

MAYO CLINIC