Lung cancer is a devastating disease.

Lung cancer is the second most common cancer among men and women in the United States, and it’s the leading cause of cancer-related deaths. In fact, more people die of lung cancer than colon, breast and prostate cancers combined.

But when the disease is detected early, lung cancer treatment can be more effective and the chances of survival can improve greatly. The trouble is that many people usually don’t experience any symptoms until the disease reaches more advanced stages.

That’s why annual lung cancer screenings are so important for those at high risk for developing the disease. Lung cancer screenings are preventive, and use a special X-ray technology to scan for problems before you start experiencing symptoms.

So, how can you tell whether you’re at high risk for developing lung cancer? And when should lung cancer screenings start and how do they work? Are there any risks associated with lung cancer screenings? Below we answer those questions and more.

Who should be screened for lung cancer?

Lung cancer screenings are typically recommended for people who are at a higher risk for developing the disease. But what does “higher risk” mean, exactly?

The biggest risk factor for lung cancer is smoking. So, if you’re an older adult who used to smoke a lot or still does, you may be considered high risk.

Your doctor will likely recommend lung cancer screening if:

• You’re 55 to 80 years old
• And you have a smoking history of at least 30 pack years (more on this below)
• And you still smoke or you quit within the last 15 years

How do you figure out your pack years? Multiply how many packs a day you smoke (assuming 20 cigarettes per pack) by how many years you’ve smoked:

• If you smoked 1 pack a day for 15 years, that's 1 times 15. So you have a smoking history of 15 pack years.
• If you smoked 1½ packs a day for 20 years, that's 1.5 times 20. So, 30 pack years.
• If you smoked 2 packs a day for 15 years, 2 times 15 equals 30 pack years.

(If you need a little help, check out this handy pack-year calculator from the University of Michigan.)

While smoking causes the majority of lung cancer cases, other risk factors for both smokers and non-smokers exist. Your doctor can work with your individual risks.

If you’re a non-smoker of average risk, there’s not enough evidence to support that lung cancer screening would be helpful. So, they’re not typically recommended.

When should you talk to your primary care doctor about whether a lung cancer screening is right for you? At your next preventive check-up or physical.

How often should a lung cancer screening be done?

If you’re at high risk for developing the disease, annual lung cancer screenings are typically recommended beginning at age 55 and lasting through age 80. But your doctor may recommend stopping screening earlier between the ages of 74 and 77.

How are lung cancer screenings done?

At one time, chest X-rays were the most commonly used tool for lung cancer screenings. But as new methods that proved to be more effective at reducing the risk of dying from lung cancer became available, that began to change.

Today, a low-dose CT scan – LDCT for short – is the primary screening tool for lung cancer. Research has shown that this method can increase the chance for survival.

What is a low-dose CT scan?

A LDCT scan is a type of X-ray that uses low doses of radiation to take multiple, detailed pictures of your lungs. It doesn’t use as much radiation as a standard chest CT scan, and it also doesn’t use intravenous (IV) contrast dye.

How does a low-dose CT scan work?

The process is really simple. You lie on a table and an X-ray machine uses a low dose of radiation to take several pictures of your lungs. With the help of a computer, the pictures are combined to create a detailed image of your lungs. The scan isn’t painful and takes just a few minutes.

Are there any risks to getting a lung cancer screening?

Lung cancer screenings do have some risks. Depending on your age, personal preferences, and medical, family and smoking history, your doctor can work with you understand the risks and benefits associated with screening.

Some of the risks you’ll likely discuss include:

• Radiation exposure – A low-dose CT exposes you to radiation. Everyone receives a small amount of radiation from the natural environment. The radiation from LDCT is about 12 months of naturally occurring radiation for an average-size person.
• False alarms – Sometimes a scan may show a finding that’s not cancer. These results are called false positives and may lead to having more tests and procedures.
• Unnecessary treatment – Low-dose CT scans can show suspicious nodules. While those nodules may never cause problems, their existence can lead to “over diagnosis.”

Should you be screened for lung cancer? Talk with a doctor to find out.

Unfortunately, unlike with colon or breast cancer, the five-year mortality rate for lung cancer hasn’t improved much over the last 40 years. And part of the reason for this is that 70 percent of lung cancers are already at Stage 3 or beyond when they’re first discovered.

The surest way to improve your chances for survival is to detect lung cancer early with a screening test.

To decide if a lung cancer screening makes sense, talk with a primary care doctor at your next preventive check-up or physical. They’ll work with you to understand your lung cancer risk factors and help you decide whether a screening is right for you. And if it is, they can help you get your screening scheduled.