The sooner lung cancer is diagnosed, the better the chances for survival. Until recently, however, early detection has been difficult—which may be one reason why lung cancer remains the No. 1 cancer killer of both men and women in the U.S. But there is good news about the disease: Doctors now have a screening test that can catch lung cancer early. It's called low-dose computed tomography (LDCT).

Anyone at high risk for lung cancer should get annual LDCT lung cancer screening.

You are at high risk if all three of these things are true for you:

1. You have a pack-year smoking history of 30 years or more. The number of packs of cigarettes you smoked per day multiplied by the number of years you smoked equals your pack years. For example: 1.5 packs a day multiplied by 20 years equals 30 pack years.

2. You smoke now, or you quit within the last 15 years.

3. You're between 55 and 80 years old.

The biggest benefit of LDCT is that it can find lung cancer in its beginning stages, which helps lower the risk of dying from the disease.

Early diagnosis also means that doctors can often use minimally invasive surgery to remove the cancer and preserve more lung tissue.

Other benefits of LDCT include:

• It's fast, painless and noninvasive.

• It uses much less radiation than a traditional CT scan of the chest.

There are possible risks, for instance:

• There may be false positives, perhaps leading to additional tests or more invasive ones.

• Sometimes false negatives occur.

If you think you're at high risk for lung cancer, ask your doctor about getting screened with LDCT.

Watson Clinic's Radiology department has been designated a Lung Cancer Screening Center by the American College of Radiology. This distinction reflects the department's commitment to providing low dose screening and diagnostic care for those considered at high risk for cancer.