Lung cancer diagnosis and detection

This page was reviewed under our medical and editorial policy by

Peter Baik, DO, Thoracic Surgeon.

This page was updated on January 8, 2023.

In determining a diagnosis, your lung cancer team will use tests and tools designed for diagnosing lung cancer, evaluating the disease and developing your individualized treatment plan. For example, imaging and laboratory tests are used to track the size of the tumor(s), monitor your response to treatment, and modify your plan when needed.

Number of lung cancer cases diagnosed in total, men and women
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Imaging tests to help detect lung cancer and look for spread

Your lung cancer team may use imaging tests to look inside your lungs and chest. There are a number of different imaging tests, including:

These imaging tests may be used to:

  • Detect lung cancer
  • Determine whether and how far the cancer has spread
  • See whether a treatment is working
  • Look for recurrence after treatment

The imaging tests your doctors may order include:

X-ray in lung cancer diagnosis

A chest X-ray uses high-energy electromagnetic radiation to provide images of the lungs and surrounding tissues. Chest X-rays may reveal abnormalities such as shaded areas, which may be evaluated further to determine whether they’re tumors.

Computed tomography (CT) scan

A CT scan reveals the anatomy of the lungs and surrounding tissues, which our cancer doctors use to diagnose and monitor tumor growth.

A CT scanner takes a series of X-rays from different angles, processes them using a computer and produces cross-sectional views of your body. CT scans can reveal lung tumors—their size, shape and position—as well as show whether the cancer has potentially spread to your lymph nodes, adrenal glands, liver or other organs.

If neurological symptoms have developed, a CT scan of the brain may be performed to check for metastasis if you cannot receive an MRI scan.

If you’re experiencing shortness of breath, your radiologist may perform a CT angiogram to check for blood clots or other blockages in the lungs.

Screening with low-dose CT

The U.S. Preventive Services Task Force recommends you undergo a low-dose CT scan each year if you meet all of the following criteria:

  • You smoke, or you quit smoking within the past 15 years
  • You have a 20-pack year history, which means smoking a pack a day for the past 20 years, or two packs daily for 10 years
  • You are between the ages of 50 and 80

This type of CT scan uses a very low dose of radiation to make detailed images of your lungs. It is safe and causes no pain. Radiation from a low-dose CT scan is similar to the amount you would get from six months of natural background radiation, whereas a regular-dose CT scan of the chest compares to two years of natural background radiation.

Magnetic resonance imaging (MRI)

Using radio waves and strong magnets, MRI is used to look for lung cancer spread to the brain or spinal cord. It may also be used to evaluate for invasion into surrounding structures.

Positron emission tomography (PET) scan

A PET scan involves injecting you with a special radioactive tracer that collects in areas with high tracer uptake. Most cancer cells have high activity and show up as bright spots on PET scans.

PET/CT scan

A PET/CT scan is a nuclear imaging technique that combines CT scan technology with positron emission tomography into one machine. A PET/CT scan shows both the structure and increased metabolic activity of cells and tissues in the body during a single imaging session. In the case of lung cancer, this scan provides a more comprehensive view of the body to determine the presence of abnormal activity, even before a tumor may have developed.

Combining PET/CT technology enables our doctors to know the extent of the disease and whether it has spread to other parts of the body. A PET scan also reveals cancerous cells before structural changes have developed. This approach helps pinpoint tumors, so that we may properly diagnose and stage the disease, and focus treatment on the cancerous tissues.

Tests lung cancer diagnosis and type

If imaging tests suggest the possibility of lung cancer, your doctors may want to examine cells from your lungs under a microscope in a lab to help confirm your diagnosis.

Lung cells can come from:

  • Lung secretions, or sputum cytology, which is mucus you cough up
  • Thoracentesis, which is fluid taken from the area around your lungs
  • Biopsy, in which a needle or surgery is used to remove cells from a suspicious area

Sputum cytology

Doctors may wish to look at a sample of your sputum if they suspect you have lung cancer that started in the major airways of the lung, such as squamous cell lung cancer. You’re asked to provide samples by coughing up mucus in the morning for three consecutive days.


If you have fluid building up around your lungs, your care team may wish to study it to determine whether you have cancer of the lining of your lungs, between your lung and your chest wall. (Fluid buildup around the lung also can be caused by heart failure or an infection.)

To remove a sample, doctors numb your skin before inserting a hollow needle between your ribs. The needle removes fluid that is then sent to a lab. The lab looks to see whether the fluid contains malignant (cancerous) cells.

Lung biopsy

During a lung biopsy procedure, your doctor removes a small piece of tissue or fluid from the chest so it can be checked for cancer cells.

Biopsies may be performed with needles or through a surgical incision. One advantage to using a needle is that it can be done through the skin or the airway and does not require surgery. However, needle biopsies remove only a small amount of tissue. This small amount of tissue may not provide enough information to diagnose cancer and to perform genomic tests.

Biopsies involving needles include:

Fine-needle aspiration (FNA): Your doctor will use a syringe that has a very thin, hollow needle to remove cells and tiny fragments of tissue from suspicious areas. An FNA is often performed to look for cancer cells in the lymph nodes between the lungs.

Core biopsy: Your doctor may use a larger needle to remove a larger sample of tissue from your airways. This procedure is called a core biopsy because the tissue that’s sampled is a small core. The larger sample size is an advantage of having a core biopsy.

Transthoracic needle biopsy: This type of biopsy may be done if your care team suspects a tumor is in the outer part of your lungs. During a transthoracic needle biopsy, a needle is inserted through the skin of your chest wall. You will be given local anesthesia to numb the area. The doctor uses a type of X-ray known as fluoroscopy or a CT scan to help guide the needle.

A transthoracic needle biopsy may allow air to leak out of the lung and into the space between it and your chest wall. This is called a pneumothorax, and it describes partial or complete collapse of the lung due to air being trapped between the lung and the chest wall.

If the leak is tiny, it should get better on its own without treatment. If the leak is large, your doctors will insert a chest tube into the space to suck out the air. It could take a day or two to stop. The tube is removed once the risk of lung collapse disappears.


Your doctor may use a bronchoscopy to look for tumors or blockages in the larger airways of your lungs. A bronchoscopy involves putting a bronchoscope, a thin flexible tube with a light and a video camera, down your throat and into your airways. Various procedures can be performed through a bronchoscope.

Below are different types of bronchoscopy your doctor may order.

Autofluorescence bronchoscopy: This technology allows our physicians to identify cancerous cells in the bronchial tubes that may not be visible under white light examination. The doctor can then remove a small sample of abnormal tissue for further analysis.

Navigational bronchoscopy: A navigational bronchoscopy combines advanced imaging techniques with electromagnetic navigation to help find and treat cancer in the lungs. This procedure allows doctors to reach tumors by advancing the scope into smaller bronchi or bronchi that are blocked by a tumor.

Robotic bronchoscopy: For patients for whom an area of concern cannot be reached via traditional, navigational bronchoscopy, robotic bronchoscopy may be an option. Robotic bronchoscopy may help certain patients avoid a transthoracic needle aspiration, which may increase the risk of complications. Robotic bronchoscopy is also designed to increase the chance of a successful biopsy.

Transtracheal FNA or transbronchial FNA

A transtracheal FNA or transbronchial FNA may be performed during a bronchoscopy or an endobronchial ultrasound.

An endobronchial ultrasound is performed by inserting a flexible scope through the mouth into the larger airways and using ultrasound waves to image the tissue.

Tests to look for spread in the chest

If you’ve been diagnosed with lung cancer, it’s important for your treatment team to know whether it’s solely in your lungs or it’s spread to the lymph nodes between your lungs or nearby nodes.

Below are tests that can help identify spread.

Endobronchial ultrasound (EBUS)

EBUS is a less invasive bronchoscopic procedure used to evaluate and sample cancerous cells in the chest. In most cases, EBUS is performed as an alternative to a mediastinoscopy, a surgical procedure used to collect samples in the chest while the patient is under general anesthesia.

Endoscopic esophageal ultrasound

With this ultrasound, doctors insert an endoscopic ultrasound device into your esophagus to see whether nearby lymph nodes contain lung cancer cells.

Mediastinoscopy and mediastinotomy

Both of these tests are used to look more closely at the lymph nodes along your windpipe and bronchial tubes. Which procedure your doctor recommends depends on where the suspected spread is and how big a sample is needed.

With a mediastinoscopy, a lighted tube is placed behind your breastbone to help look around and take samples to be analyzed in a lab. A mediastinotomy may be needed if certain lymph nodes can’t be reached with the mediastinoscopy procedure. A mediastinotomy requires an incision (roughly 2 inches long) be made between the second and third ribs on your left side. This procedure allows your doctor to also look around and collect samples for analysis.

Thoracoscopy/Video-Assisted Thoracoscopic Surgery (VATS)

Your doctor may order a thoracoscopy to determine whether your cancer has invaded the space between your lungs and chest wall or the lining of these spaces. Your doctor will use a thoracoscope—a thin, flexible tube that has a light and a tiny video camera on the end of it—to see inside your chest. The tube is inserted through a small incision that is made between your ribs and the bottom of your shoulder blade.

Thoracoscopy also may be used in some cases as a treatment for early-stage lung cancer. The part of your lung where the cancer is located may be removed using this procedure.

Additional tests that may help with diagnosis and treatment plans

Your doctor also may order the following tests to aid in your diagnosis and determine your individual treatment plan:

Blood tests for lung cancer

Currently, no blood test can detect lung cancer. However, blood tests may be used to help determine your overall health and whether you’re able to undergo surgery if that is part of your treatment plan. Blood tests that your doctor may order include:

Complete blood count (CBC): A CBC looks at a number of different types of blood cells. Your red blood cell count can indicate whether you have anemia; the count would be low. A low number of platelets could suggest that you might have trouble with bleeding. Low white blood cell counts could suggest that you’re at risk of infections. Your doctor may order a CBC several times during your treatment, especially if you have been given cancer drugs, as these may affect your bone marrow, which is where blood cells form.

Other blood chemistry tests: Lung cancer may spread to other organs, such as your liver, kidneys or bones. Your doctor may order different blood tests that can indicate whether your cancer has spread to these sites. An example: A higher-than-normal level of calcium and alkaline phosphatase may indicate that your lung cancer has metastasized to the bone.

Liquid biopsies: In the fall of 2020, the U.S. Food and Drug Administration approved two blood tests—Guardant360 CDx® and FoundationOne Liquid CDx®—that may be used to look for genetic changes in a tumor that may help guide treatment. Known as liquid biopsies, both were approved for non-small cell lung cancer. Guardant360 CDx® looks for changes in more than 60 genes, while FoundationOne Liquid CDx® looks for changes in more than 300 genes. The genetic changes that are detected may then be matched to available drugs and help personalize your treatment.

Lab tests for lung cancer

Lung cancer genomic testing: Advanced genomic testing examines a tumor on a genetic level to look for the DNA alterations that are driving the cancer’s growth. By identifying the mutations that occur in a cancer cell’s genome, we can better understand what caused the tumor and tailor treatment based on the findings from the test. The most common tumor markers tested for in lung cancers are EGRF, KRAS and ALK.

Nutrition panel: With this test, we evaluate patients for deficiency of nutrients, such as vitamin D and iron. The test helps us identify the nutrients patients need replaced or boosted to support their quality of life. Learn more about our nutrition therapy program.

City of Hope Chicago four-day lung nodule diagnosis

Our lung cancer care team at City of Hope Chicago has developed a Four-Day Lung Nodule Diagnosis Program to get your results faster, in as few as four days after your initial consultation. A team of our lung experts begin working to help you get the information you need to make decisions about your care before you even walk in the door of our facilities.

Experts may include:

  • Interventional radiologist
  • Pulmonologist
  • Thoracic surgeon
  • Medical oncologist
  • Radiation oncologist

From the moment you call, we expedite the scheduling process—from insurance verification to collecting your medical records—to get you in as quickly as possible. By the time you arrive at City of Hope Chicago, our expert lung team has already reviewed your records. During your initial consultation, you’ll meet with an internist, who in conjunction with a thoracic surgeon and pulmonologist will determine which type of biopsy, if any, should be performed. More tests on the nodule will be conducted over the next day or two, and your results will usually be available by Day 3 or 4 of your visit.

If you learn you have cancer, a medical oncologist, a thoracic surgeon and, possibly, a radiation oncologist will recommend further in-depth testing or a comprehensive treatment plan tailored to your specific case and your individual needs. You will also meet with your care team, which may include a registered dietitian and naturopathic, behavioral health and other supportive care providers. These clinicians help you manage side effects and maintain your strength during treatment.

Our goal is to provide you with an accurate diagnosis with the sense of urgency you deserve. If you’re interested in scheduling an appointment with our rapid lung-nodule diagnosis program, call us or chat online with a member of our team.

Next topic: How is lung cancer treated?

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