If you’ve heard the rumor that biopsies can cause cancer to spread, you may be nervous about a past or future lung biopsy. In reality, the risk that a cancer biopsy, including a lung biopsy, will cause cancer to spread is extremely small. Medical experts confirm that the benefits of a biopsy far outweigh the risks for most people. Continue reading to learn more about lung biopsies and the risk of cancer spreading.

What Is a Lung Biopsy?

A lung biopsy is a test that can help diagnose lung cancer or other lung conditions. During a biopsy, your health care provider will remove a small sample of your lung tissue for testing. There are several biopsy techniques.

Your health care provider may choose to perform a needle biopsy. A needle biopsy does not require surgery or an incision. In a needle biopsy, a doctor uses a thin, hollow needle to remove a lung or lymph node tissue sample.

There are two main types of needle biopsy — fine needle aspiration biopsy and core needle biopsy.

Fine Needle Aspiration Biopsy

You may have a fine needle aspiration biopsy if your provider wants to withdraw (aspirate) a sample from a small mass or the lymph nodes around your lungs. This can be done with local anesthetic, and most people are able to return home the same day.

Core Needle Biopsy

You may need a core needle biopsy if your provider needs a larger tissue sample than a fine needle aspiration biopsy can give. A core needle biopsy removes a core of tissue for examination.

Biopsies During Other Diagnostic Tests

Both the core needle biopsy and the fine needle aspiration biopsy can be performed alone or as part of other diagnostic procedures for lung cancer, such as bronchoscopy or thoracoscopy.

During bronchoscopy, a doctor will insert a bronchoscope — a tube with a light and a camera at one end — into your mouth and down your windpipe to look at your lungs from the inside. If the doctor sees any tissue they are concerned about, they can take a biopsy during the procedure.

Thoracoscopy is usually used to see whether cancer has spread to the area between the lungs and the chest wall. For a biopsy during thoracoscopy, your provider will use a long flexible tube with a camera on the end (called a thoracoscope) to guide the needle through your skin and chest wall to the affected area. This type of biopsy is called a transthoracic needle biopsy.

Occasionally, a doctor may need to take a sample of tissue through an open lung biopsy. This is a surgical procedure under general anesthesia, during which a doctor makes an incision in your chest and removes a lung tissue sample.

Some people may need to stay in the hospital for a few days after these diagnostic tests, if they receive general anesthesia.

Why Might You Need a Biopsy?

A biopsy is often the best way to know for sure if you have cancer and get important details about what kind of cancer you have. Other tests for lung cancer, such as magnetic resonance imaging (MRI) or chest X-ray, may not give your cancer care team enough information to diagnose lung cancer.

The lung tissue sample taken during a biopsy is sent to a lab for further tests. Here, a doctor will look at the sample under a microscope. Examining the lung sample under the microscope can help with diagnosis and cancer staging.

The lung tissue sample can also be used for molecular testing to identify lung cancer biomarkers (signs of genetic changes in cancer cells). These biomarkers may help your cancer care team understand how aggressive your cancer is and which treatment plan may work best for you. For example, certain biomarkers may mean that some targeted therapies or immunotherapies can help treat your cancer.

Can Biopsy Spread Cancer?

The controversial idea that a cancer biopsy may cause cancer to spread gained attention in recent years when a doctor specializing in diseases of the urinary tract published a book that criticized biopsies for prostate cancer. This doctor’s medical license was later suspended by the state of Florida.

There have been rare cases where a biopsy has caused cancer cells to move to another part of the body — known as tumor seeding. In theory, the cancer cells can begin to grow in a new area after being pushed there by a needle biopsy. In people with lung cancer, a needle biopsy could theoretically cause tumor cells to spread into the tiny air sacs in the lungs or into the bloodstream.

However, several medical studies have found that the risk of tumor seeding is very low for lung cancer and other types of cancer studied. A 2022 study evaluated the risk of tumor spread with lung biopsy in people with early-stage non-small cell lung cancer (NSCLC). In the study, researchers looked at three groups of people — people who had a percutaneous needle biopsy, people who had a bronchoscopic biopsy, and people who didn’t have a biopsy before lung cancer surgery. Researchers found that a needle lung biopsy before lung cancer surgery did not increase how often people experienced tumor spread, recurrence (when cancer comes back), or death.

What Are the Risks of Lung Biopsy?

Although biopsies are generally safe, they do have some potential risks. Talk to your cancer care team about the risks of the biopsy procedure you will have.

Potential risks of lung biopsy include:

• Bleeding
• Infections
• Pneumonia (lung infection)
• A collapsed lung

Talk to Your Health Care Team

Lung biopsy is an important tool for diagnosing and treating lung cancer. When a lung biopsy is performed by a trained specialist, the risk of tumor seeding is extremely rare. For most people, the benefits of a lung biopsy outweigh the potential risks. Ensuring a cancer specialist performs and analyzes your lung biopsy can further decrease your risks.

If you have concerns about getting a biopsy, talk to your cancer care team to learn more about the risks and benefits of a lung biopsy. You may want to ask questions, such as:

• Why is a lung biopsy recommended?
• What type of biopsy is recommended?
• What’s the expertise of the provider who will perform the biopsy?
• What are the potential side effects and risks of this biopsy procedure?
• What should I expect during the procedure?
• How should I take care of myself after the procedure?
• When should I expect the results of the biopsy?

Talk With Others Who Understand

On MyLungCancerTeam, the social support network for people with lung cancer and their loved ones, more than 12,000 members come together to ask questions, give advice, and share their stories with others who understand.

Have you had a lung biopsy? What was your experience like? Share your insights in the comments below, or start a conversation by posting on your Activities page.