Non-Small Cell Lung Cancer Diagnosis

The lungs are the two large organs located on either side of the heart that enable you to breathe. Air travels through the nose and mouth into the trachea, also known as the windpipe.

The trachea divides into two airways, or bronchi, which lead to the spongy tissue of the lungs, and then divide into increasingly smaller breathing passages. The smallest of these passages are called bronchioles. The bronchioles lead to small air sacs called alveoli. This is where oxygen is absorbed into the bloodstream and where carbon dioxide passes out of the body.

The lungs are divided into sections called lobes. There are three lobes in the right lung and two in the left. The lungs are surrounded by the pleural cavity, which consists of a thin lining of membranes, called pleura, that are filled with a small amount of fluid. The pleura enable the lungs to move without friction as they expand and contract within the chest.

There are two main types of lung cancer. About 85 percent of lung cancers are the non-small cell variety, while the remaining 15 percent are considered small cell lung cancer.

There are three main types of non-small cell lung cancer: squamous cell carcinoma, large cell carcinoma, and adenocarcinoma.

Squamous cell carcinomas arise from the flat cells lining the lungs’ airways. They are often located in a major, central airway, such as the bronchi, the two airways leading from the trachea, or windpipe, into the lungs.

Adenocarcincomas start in gland cells that secrete mucus and line the alveoli, the small air sacs.

In large cell carcinoma, the cells look large and abnormal under a microscope. It is more aggressive and can develop anywhere in the lung.

Early non-small cell lung cancer often doesn’t have any symptoms, which is why screening people at high risk for developing the condition is important. When symptoms do develop, the cancer may be more advanced. Symptoms may include a persistent cough, chest pain, hoarseness, coughing up blood, trouble breathing, and fatigue.

If you are experiencing symptoms of non-small cell lung cancer, or a low-dose CT scan shows a suspicious growth, doctors may recommend additional imaging tests and a biopsy.

A CT scan is a type of X-ray that produces detailed, three-dimensional, cross-sectional images of tissues and organs, which are displayed on a computer monitor. These scans are more likely to reveal a possible lung cancer than a conventional X-ray.

A CT scan can also show whether area lymph nodes, small immune system glands located throughout the body, are enlarged as a result of cancer.

Before the scan, doctors may give you a contrast solution to help enhance the images. This may be given as a liquid or an injection into a vein.

If doctors at Perlmutter Cancer Center find a suspicious growth during a CT scan, they may follow up with a PET/CT scan if they need more detailed images. Whereas the CT portion of the scan uses X-rays to create cross-sectional images of the body, the PET scan detects tumor activity using a safe amount of a radioactive glucose, or sugar, injected into a vein.

The glucose collects in cancer tissue and is detected with a special camera. The images from the camera are combined with the images from the CT scan to provide information about the tissue’s metabolic activity or how quickly a growth processes sugar. The more quickly the tissue metabolizes the sugar, the more likely it is to be cancerous or inflamed.

While imaging tests can indicate that a tumor may be cancerous, only a biopsy—the removal of tissue for examination under a microscope—can confirm the diagnosis. Cytopathologists, doctors who study diseases at a cellular level, examine biopsy tissue under a microscope to determine whether non-small lung cancer is present and what type it may be. The type of biopsy used to remove tissue depends on where doctors think the cancer may be growing, based on the imaging tests.

CT-guided Biopsy

CT-guided biopsy allows doctors to biopsy a tumor that is easily reached from outside the body. After numbing the skin with a local anesthetic, doctors insert a small needle between the ribs and into the lungs to remove a sample of tissue. Doctors use CT scanning to help guide the needle during this process.

Bronchoscopy

A bronchoscopy enables doctors to view and biopsy tumors that occur in the airways of the lungs. During this procedure, doctors insert a bronchoscope, a long, flexible tube with a camera on its end, through the nose or mouth and into the airways. After they locate the tumor, they can pass small surgical instruments through the scope to take tissue and cell samples.

Sometimes doctors use fluoroscopy, an imaging technique that uses two-dimensional X-rays, to guide the insertion of the bronchoscope.

The procedure is done using sedation or general anesthesia. An anesthetic spray is applied to your throat beforehand. After the medication wears off, you can go home.

Endobronchial Ultrasound

If doctors suspect cancer is present, they may use endobronchial ultrasound to make the initial diagnosis. They can use this procedure to sample a lung tumor when it is next to an accessible airway. This approach can also allow doctors to locate and biopsy enlarged lymph nodes found on imaging tests to determine whether the cancer has spread.

In this procedure, doctors place a bronchoscope with an ultrasound device attached to it into airways in the lungs. The ultrasound device creates pictures of the surrounding lung tissue and structures, such as lymph nodes, using sound waves. The images are displayed on a monitor.

Sometimes doctors insert a small ultrasound probe that’s attached to the end of a catheter, or hollow tube, through the channel of a standard bronchoscope. This procedure, called radial endobronchial ultrasound, is similar to endobronchial ultrasound, but the long probe can reach farther into the lungs than in standard endobronchial ultrasound. Doctors can create images of suspicious growths deep within the lungs, which they can then sample using tools placed through the probe.

Before either of these procedures, a doctor gives you a sedative or anesthesia to relax you and a local anesthetic to numb the throat. You can return home after the sedative or anesthesia wears off.

Electromagnetic Navigation Bronchoscopy

Electromagnetic navigation bronchoscopy helps doctors locate lung tumors using technology that’s similar to the global positioning system (GPS) in cars. Doctors at Perlmutter Cancer Center are early adopters of this technology.

During the procedure, doctors place sensors on your chest and back, which creates an electromagnetic field. Then a probe or catheter with another sensor on its end is threaded into the lungs through a bronchoscope.

Doctors use the electromagnetic field to track the position of the probe and bronchoscope on a detailed, three-dimensional CT scan of the chest as they move through the lungs. They also use this scan to map out a plan for reaching the area of the lungs that needs to be biopsied before the procedure. With the guidance system, doctors can perform biopsies of tissue in distant areas of the lungs that are hard to reach using conventional bronchoscopy.

This procedure requires general anesthesia. Doctors apply a local anesthetic to your throat beforehand. You can return home after the anesthesia wears off.

Doctors may use a number of tests to determine whether non-small cell lung cancer has spread to other areas of the body, and if it has, how far.

Endoscopic Esophageal Ultrasound

Endoscopic esophageal ultrasound helps doctors reach swollen lymph nodes near the esophagus, the long muscular tube that runs from the mouth to the stomach. Doctors insert the endoscope—a long, thin, flexible tube with a light and video camera on the end, in this case with an ultrasound device attached—through the mouth or nose and into the esophagus.

If a doctor sees swollen lymph nodes on the ultrasound, he or she can place a small needle through the endoscope and go through the wall of the esophagus to take a tissue sample.

This procedure requires sedation. A local anesthetic is also sprayed in your throat. You can return home after the sedation wears off.

Mediastinoscopy

Mediastinoscopy is a test to determine whether lung cancer has spread to lymph nodes in the center of the chest. During this procedure, the doctor makes a small incision in the neck and inserts a mediastinoscope, which is similar to an endoscope. It is placed behind the breastbone and in front of the trachea, or windpipe, to view images of area lymph nodes on a computer monitor. Doctors can insert small surgical tools through the scope to take tissue samples from these lymph nodes.

Mediastinoscopy may be used to confirm that a biopsy is taken from an endobronchial ultrasound is truly negative. In many instances, endobronchial ultrasound helps to avoid mediastinoscopy.

This procedure is performed using general anesthesia, and you may need to stay in the hospital overnight for monitoring.

Thoracoscopy

A thoracoscopy may help doctors determine whether lung cancer has spread to the pleural cavity surrounding the lungs. Doctors place a thoracoscope, which is like an endoscope, through a small incision between the ribs in the chest wall to inspect the pleural cavity and lining for signs of cancer.

They can take tissue samples with small surgical tools placed through the scope. This procedure can also be used to take tissue samples from tumors on the outer parts of the lungs and from area lymph nodes. Doctors may also remove fluid in the pleural cavity to check for cancer cells.

Thoracoscopy requires general anesthesia, and you may need stay in the hospital overnight so you can be monitored.

After biopsy tissue has been removed and cancer is confirmed, a pathologist may use it to conduct specific stains, molecular testing, or both, to determine if there are any specific “driver alterations,” such as epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), and ROS1, among many others. If so, doctors may be able to use targeted drugs, which home in on these specific alterations in cancer cells, as a treatment option. Special molecular tests called next-generation sequencing are also used to profile cancer cell genes to help tailor therapy for every individual.

Other tests are used to look for biomarkers that may predict the benefit of immunotherapy, which target a patient’s immune system to try to boost the immune response against cancer.

Perlmutter Cancer Center researchers are studying tumor tissue, blood, pleural fluid, stool, and other clinical samples to identify biomarkers that better predict response to treatments so they can be individualized for maximum benefit.