Lung Cancer Screening Benefits and Risks

Lung cancer screening can help detect cancer in the lungs before it becomes symptomatic. A low-dose computerized tomography (LDCT) scan is the only recommended test for this purpose. It is often performed in healthy people who have no symptoms, but who are at high risk of lung cancer

If you meet the criteria, being screened every year can be an effective way to catch the disease early, begin treatment promptly, and perhaps even cure it.

a doctor showing a patient her tablet
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Who Should Be Screened?

Knowing the benefits and risks of lung cancer screening is important. But screening is not appropriate for everyone, so you first need to know if it is even advised for you.

The U.S. Preventive Services Task Force (USPSTF) recommends annual screening for lung cancer using LDCT of the chest for high-risk people who meet all of the following criteria:

  • Age between 50 and 80
  • 20 pack-year or more history of smoking
  • Currently smoke or quit within the past 15 years
  • Overall health is good enough to undergo treatment if diagnosed with lung cancer

The USPSTF does not recommend using other criteria for screening, such as exposure to carcinogens other than cigarette smoke.

Pacemakers and rods can interfere with the screening process and produce low-quality results, so those with these metal implants may not benefit from lung cancer screening.

Talk to your doctor if you want to be screened for lung cancer. They can make sure it's appropriate for you and, if so, refer you to a screening facility.

If You Aren't Eligible

Not qualifying does not mean you are not at risk for lung cancer. It's important to be aware of any of your risk factors. This includes smoking, but also things like:

Family history may also play a role in the development of lung cancer. Other factors, such as HIV infection, can increase your vulnerability to lung cancer as well.

If you experience shortness of breath, persistent cough, or any other symptoms of lung cancer, be sure to bring them to your doctor's attention immediately—whether you routinely get screened for lung cancer or not.

What Is a Low-Dose CT?

A low-dose CT scan involves lying on a table that slides into a machine equipped with a scanner that revolves around you.

Multiple X-ray images are taken from different angles, and a computer generates a three-dimensional model of your lungs by compiling them together. A contrast agent may be used to help with visualization.

The scan only takes a few minutes and is not painful.

Benefits of Lung Cancer Screening

The main benefit of screening is a lower chance of dying from lung cancer, which accounts for many deaths in current and former smokers.

For people at high risk of lung cancer, getting yearly LDCT scans before symptoms start helps lower the risk of dying from lung cancer.

The mortality benefit of lung cancer screening comes from the fact that if it's caught at a very early stage, lung cancer can often be treated effectively. 

As with any type of screening, not everyone who gets screened will benefit it. Screening with LDCT will not find all lung cancers, and not all of the cancers that are found will be found early.

Risks

Risks of screening include false-positive results (suggesting that a person has lung cancer when no cancer is present) and radiation exposure, which can cause cancer in otherwise healthy people.

False-positive results that led to an invasive procedure has been estimated at between 2% and 4%.

Beyond that, there is some concern over radiation exposure that comes with LDCT. This form of imaging does emit more radiation than a traditional X-ray, and the CDC warns that repeated LDCTs can cause cancer.

That said, the excess risk has been reported as less than 1% for both men and women.

Nevertheless, this is one reason why screening is only recommended in those for whom the scan's benefits outweigh its risks, which is this case for those who qualify.

An LDCT scan of the lungs does not involve scanning of the abdomen and should involve minimal risk to those who are pregnant.

What Happens If Result Is Positive

Sometimes screening tests will show something abnormal in the lungs or nearby areas that may be cancer, but most of these abnormal findings turn out not to be cancer.

More CT scans or other tests like a magentic resonance imaging (MRI) scan and a positron emission tomography (PET) scan will be needed to learn more.

A biopsy will also be performed. A sample of lung tissue is taken for a closer examination under a microscope. A biopsy does not mean you have cancer, but it is needed to officially make (or rule out) the diagnosis.

If a diagnosis of lung cancer is confirmed, it is important that you seek support from loved ones and maintain open communication with your provider to discuss treatment options.

Options will depend on your lung cancer's type and stage. They may include surgery, chemotherapy, immunotherapy, and more.

You may also wish to speak with other patients who have undergone or are undergoing treatment for lung cancer. A lung cancer diagnosis is not something you need to handle alone.

Can I Get a Chest X-Ray Instead?

Chest X-rays are not considered good for lung cancer screening because overlapping structures can make it difficult to spot a tumor. Moreover, X-ray imaging cannot visualize soft tissues.

An X-ray sends small doses of radiation through the body. Bones, which are high in calcium, show up clearly on X-ray because of their density and because they have a higher atomic number than most elements and can absorb the X-rays. This results in them appearing white on the screen.

Soft tissues such as those in the lungs, however, appear in various shades of grey on X-ray. This can make the film difficult to read. An X-ray may detect an unusual mass in the lungs, but it would be extremely hard to ascertain if it is a tumor.

The 360-degree computerized image of your lungs that is created by a CT scan allows for much more detail to be captured. This helps ensure a more accurate diagnosis of lung cancer.

A Word From Verywell

Genetic testing is another tool for checking for your risk of lung cancer, though it is not considered or used as a screening test. Certain mutations can increase your risk of developing this disease, so testing can help identify if you have any inherited lung cancer risks.

Most people who develop lung cancer at a younger age, commonly women and non-smokers, have a genetic predisposition to the disease. For example, EGFR T790M mutations are more commonly found in lung cancer patients who have never smoked than in patients who have.

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  1. Richards TB, White MC, Caraballo RS. Lung cancer screening with low-dose computed tomography for primary care providers. Primary Care: Clinics in Office Practice. 2014;41(2):307-330. doi: 10.1016/j.pop.2014.02.007

  2. U.S. Preventive Services Task Force. Lung cancer: Screening. Updated December 31, 2013.

  3. Centers for Disease Control and Prevention. Who Should Be Screened for Lung Cancer? Sept 22, 2020.

  4. American Cancer Society. Can Lung Cancer Be Found Early? Updated November 17, 2020.

  5. Centers for Disease Control and Prevention. Who Should Be Screened For Lung Cancer? Mar 11, 2021.

  6. National Lung Screening Trial Research Team. Reduced lung-cancer mortality with low-dose computed tomographic screening. N Engl J Med. 2011 Aug 4;365(5):395-409. doi: 10.1056/NEJMoa1102873

  7. Chen H, Rogalski MM, Anker JN. Advances in functional X-ray imaging techniques and contrast agents. Phys Chem Chem Phys. 2012;14(39):13469-13486.