Lung cancer is the third 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. When lung cancer is found early, treatment can be much more effective. Plus, lung cancer screenings are done quickly, and they’re usually covered at 100% by insurance for people who are at high risk.

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.

What is a lung cancer screening exactly?

Lung cancer screenings are preventive and use a special X-ray technology to scan for problems before you start experiencing symptoms. The reason why doctors recommend screenings for people without symptoms is that lung cancer, like most cancers, has very few symptoms in the early stages.

Usually, symptoms become noticeable when the cancer has become more advanced. Even then, people often mistake symptoms of lung cancers for pneumonia, other infections or simply the long-term effects from smoking.

Who should be screened for lung cancer: Screening age and “pack years”

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.

Lung cancer screening guidelines

Both the United States Preventive Services Task Force (USPSTF) and the American Cancer Society (ACS) continually evolve the lung cancer screening guidelines. In 2023, the guidelines were updated to qualify even more people to get screened for lung cancer, with the screening age and total “pack years” being lowered. Most private insurances, as well as Medicaid and Medicare, also extended plan coverage to align with these new guidelines. Depending on your individual risk factors, your doctor may recommend that you make the choice to get screened if:

  • You’re 50 to 80 years old
  • And you have a smoking history of at least 20 pack years (more on this below)
  • And you still smoke or you quit within the last 15 years

How to calculate 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.

Why lung cancer screening isn’t recommended for everyone

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.

However, while smoking causes the majority of lung cancer cases, other risk factors such as a family history of the disease, previous radiation therapy or exposure to certain chemicals exist for both smokers and non-smokers. Your doctor can work with you to discuss your individual risks.

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

How often lung cancer screenings should be done

If you’re at high risk for developing the disease, yearly lung cancer screenings are often recommended beginning at age 50 and lasting through age 80.

But your doctor may recommend stopping screening earlier if it’s been more than 15 years since you quit smoking, or you have certain health conditions that limit your life expectancy or willingness to have a curative lung surgery.

How to test for lung cancer: Low-dose CT scans

At one time, chest X-rays were the only tool used for lung cancer screenings. But today, a low-dose CT scan – LDCT for short – is the primary screening tool for lung cancer and it’s generally considered safe. 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. In fact, it can detect tiny lesions as small as a grain of rice, which would not be visible on a traditional chest X-ray.

Low-dose CT doesn’t use as much radiation as a standard chest CT scan, and it also doesn’t use intravenous (IV) contrast dye, which means the screening itself can be done more quickly and with less risk.

How does a low-dose CT scan work?

The process is really simple. The scan isn’t painful and takes just a few minutes. Here’s a general overview of what to expect:

  • You’ll lie down on a table that’s attached to the CT machine.
  • The table will slowly move through the machine’s X-ray tube, which looks a bit like a large doughnut, as it rotates.
  • As the X-ray tube uses a low dose of radiation to take several pictures of your lungs.
  • Then with the help of a computer, the pictures are combined to create a detailed image of your lungs and the surrounding area.

How long does a low-dose CT scan for lung cancer take?

The screening itself only takes a few minutes, but your total appointment time may be around 30 minutes. There’s also no downtime and you’ll be able to return to normal activities right away.

Is there anything you need to do to prepare for a lung cancer screening?

There’s no personal prep work you need to do before a LDCT scan. But we typically recommend people leave jewelry or watches at home. They’ll need to remove any metal before the scan begins and this helps reduce the chances of losing important items.

Depending on the clinic, you may be asked to change into a gown for the test, but it’s possible you’ll be able to keep your street clothes on.

Lung cancer screening results: How long it takes and what happens if it’s abnormal

A radiologist – a doctor who is expertly trained in medical imaging – will review the images taken during your screening and report the results. Those results are typically shared with your primary care doctor or lung specialist. This is especially important if scans show abnormal or potentially abnormal lesions or growths so your care team can coordinate any next steps.

When you get screened at a HealthPartners location, you can expect your results and any immediate next step recommendations within a couple of days of your screening.

What if your lung cancer screening results are abnormal?

If your screening results show something abnormal in your lungs or surrounding area, next steps will depend on several factors. And your care team will walk you through everything.

It’s likely that additional imaging tests will be recommended. A biopsy – where a small tissue sample is taken from your lungs and tested for cancerous cells – may also be recommended.

How accurate are LDCT scans for lung cancer?

Research indicates that low-dose CT scanning technology can detect 80% of lung cancer at an earlier stage. So, it’s possible a scan won’t detect cancer. But this is also why annual screenings for those at higher risk for developing the disease may be recommended over the course of several years.

It’s also possible for screening results to show something that looks abnormal, but isn’t cancer, which we talk about more in the next section.

Lung cancer screening risks

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 may include:

  • Radiation exposure– A low-dose CT exposes you to some 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 positives– 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– While low-dose CT scans can detect 80% of lung cancers at an early stage, they can also show suspicious nodules. While those nodules may never cause problems, their existence can lead to “over diagnosis.”

How much lung cancer screenings cost

Lung cancer screenings are often covered 100% by private insurance plans, as well as Medicaid and Medicare plans, for those who meet eligibility criteria.

However, it’s always a good idea to check with your insurance company to understand your specific plan’s coverage. And if you don’t have insurance, your doctor may be able to recommend programs that offer free or low-cost screenings.

If you have HealthPartners insurance, you can check your plan’s coverage online.

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% of lung cancers are in an advanced stage 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 is right for you, talk with a primary care doctor at your next preventive checkup 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.