A "positive" result means that the low-dose CT scan shows something abnormal. This is usually a nodule of a concerning size. You may need to have additional scans or other procedures to find out exactly what it is. These next steps should be discussed with you by your physician and/or the team of experts at the screening center.
A "negative" result means there were no abnormal findings at this time on this low-dose CT scan. It does not mean that you will never get lung cancer. Your doctor should discuss when and if you should be tested again.
There may also be an "indeterminate" result and your doctor may recommend watchful follow-up and further imaging at a later time.
The best way to reduce your lung cancer risk is to never smoke or stop smoking now. If you smoke, talk to your doctor about ways to help you quit.