If lung cancer is detected early, when it's small and hasn't had the chance to spread, it is more likely to be treated successfully. But lung cancer can be hard to catch at an early stage. People with lung cancer often don't show symptoms until it's more advanced. Even then, it's easy to attribute those symptoms to other causes.

This is where screening comes in. Simply put, screening is the process of looking for cancer and other diseases in people who don't have symptoms. If you have a high risk for lung cancer, these tests could save your life.

Studies have shown that low-dose CT (LDCT) scans can help detect lung cancer early in certain high-risk people.

LDCT scans use X-rays to create detailed 3-D images of your lungs. They are totally painless and require no special preparation. All you do is lie down on a narrow table as it passes through a ring-shaped CT scanner. At most, you may be asked to hold your breath a few times during the test.

LDCT scans can spot abnormal areas that regular chest X-rays might miss. The benefit is significant: a lower risk of dying from lung cancer. Some potential downsides, however, include:

• Many abnormalities surfaced in LDCT scans do not turn out to be cancer. These findings can cause unnecessary anxiety and lead to more testing that also has risks.
• More tests may determine whether the abnormal area is cancer. Sometimes, these exams can lead to complications.
• Each scan uses a small amount of radiation.

Keep in mind: LDCT scans do not find all lung cancers. It's also possible the cancers they do find may have already progressed to a later stage.

The U.S. Preventive Services Task Force and other expert groups have created specific guidelines for who should get screened. They recommend yearly LDCT scans for people who are:

• Between the ages of 50 and 80

And…

• Current smokers, or former smokers

And…

• Have a 20-pack-year history of smoking. A pack-year is the equivalent of smoking an average of one pack of cigarettes per day for a year. In other words, smoking a pack a day for 20 years equals 20 pack-years. Smoking two packs a day for 10 years also equals 20 pack-years.

Even if you meet all the testing criteria, it's important to talk with your doctor about your personal health and risk. Some questions to consider asking are:

What are the limits and risks of screening? Understanding potential outcomes before you go for a screening may reduce feelings of fear or anxiety.

Am I healthy enough to get a screening? The risks of screening outweigh the benefits for certain people. For example, if someone can't have lung surgery to remove the cancer, screening may not be a good option.

Where should I go for a lung cancer screening and treatment, if needed? Expert groups advise having lung cancer screenings at centers with the proper experience. These facilities should have specialists on staff. They can handle follow-up appointments, questions, and care.

Is there any cost associated with the annual screening? Medicare and many private health insurance plans cover lung cancers screenings. It's a good idea to ask your doctor whether insurance will cover it before scheduling a test.