Lung Cancer: Diagnosis & Staging

For many people, the first sign that they may have lung cancer is the appearance of a suspicious spot on a chest x-ray or CT scan. A diagnostic image alone, however, is not enough to determine whether the growth is cancer and, if so, what type of cancer it is.

Most people who come to Memorial Sloan Kettering for the treatment of lung cancer first meet with a surgeon. He or she will work with pathologists, radiologists, and other lung cancer specialists to determine the specific type of lung cancer you have and how advanced it is. These findings help your disease management team to develop the treatment plan that will be most successful for you.


If your doctor suspects that you have lung cancer, you will need to have a biopsy. Performing a biopsy is the only way for your doctors to determine whether the suspicious growth is a cancer, and whether that cancer is a small cell or non-small cell lung cancer.

In a lung biopsy, tissue from the growth is removed and then examined by a pathologist. There are a variety of techniques that your doctor might use to remove tumor tissue.


During a bronchoscopy, you will first be put under anesthesia. A physician will then place a small tube called a bronchoscope through the nose or mouth, down the throat, and into the bronchial passages, where small tools are used to remove some tissue. Sometimes cells are collected by washing out or brushing the bronchial passages during the procedure. Bronchoscopy is used when the tumor is accessible from the airway.

Bronchoscopy can also be used if the suspicious growth is located just outside the bronchial tubes. Using a technology called endobronchial ultrasound (EBUS) to guide the placement of the bronchoscope and biopsy needle, physicians can precisely remove samples outside the bronchial tubes.

Transthoracic Needle Biopsy

If the suspicious growth cannot be reached by a bronchoscopy, your physician may recommend a needle biopsy through the chest wall. In this procedure, also called transthoracic needle biopsy, you will receive anesthesia, and a needle will be inserted through the skin directly into the suspicious spot to remove a small sample of tissue for analysis. Most needle biopsies are performed by physicians called interventional radiologists, who use x-rays or a CT scanner to guide the needle.

Other Methods for Biopsy

Occasionally, a biopsy is performed using an endoscope placed through the mouth into the esophagus, the tube that leads from the mouth to the stomach. This approach is called endoscopic ultrasound. At other times, because of the location or size of the suspicious mass, a surgical operation may be necessary to perform the biopsy.

Identifying the Type of Cancer

After tissue samples are taken, pathologists who specialize in thoracic cancer study the tissue under a microscope to determine what type of lung cancer you have. The pathologists are able to tell one type of lung cancer from another by looking closely at the cancer cells’ shape and other distinguishing features.

Determining what type of lung cancer you have will enable your doctors to stage the tumor accurately and to begin identifying the best treatment approach. Understanding what type of cancer you have is also important because each type responds differently to certain chemotherapy drugs.

In addition to standard pathology tests, Memorial Sloan Kettering performs molecular testing of tumors in all patients with non-small cell lung cancer. We are one of only a few hospitals in the world to offer this type of personalized medicine.

Learn more about personalized medicine at Memorial Sloan Kettering.


Once the pathologist determines whether you have small cell or non-small cell lung cancer, the next step is to identify the extent to which it has spread, or metastasized, to other parts of the body. This is called staging. To determine the stage of your cancer, you may undergo one or more imaging studies, including:

  • CT scans of the chest and possibly the abdomen and pelvis
  • An MRI scan of the head
  • A combined PET/CT scan of all parts of the body between the neck and thighs

Your doctor may also recommend additional tests, depending on any symptoms the cancer may be causing. In some cases, additional procedures may be used to obtain more tissue specimens or to determine the exact location of a tumor.

After your physicians know how extensively the cancer has spread, they will determine the stage of the disease. Staging takes into account:

  • the size and location of the initial (primary) tumor
  • the extent of its spread to nearby lymph glands (nodes)
  • whether it has invaded other organs in the body (called metastases)

Staging is a critical step in choosing the best treatment for you. The stage is based on the location(s) of the tumors at the time the cancer is first discovered. The stage stays the same throughout your course of treatment.

The extent of lung cancer is described using four stages:

  • Stage I — The cancer developed in and is confined to one lung.
  • Stages II and III — The cancer developed in one lung but has spread to nearby chest structures or lymph glands.
  • Stage IV — The cancer has spread from one lung to the other or to another organ like the bone, brain, liver, or adrenal gland (a hormone-releasing organ that sits on top of the kidney).