As an expert in distinguishing lung cancer types, pathologist William Travis provides precise diagnoses. His work is essential to developing the most effective treatment strategy for each patient.
For many people, the first clue that they 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 patients who come to Memorial Sloan-Kettering for the treatment of non-small cell lung cancer first meet with a surgeon. He or she will work together 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 lung cancer disease management team to develop a treatment plan that will be most successful for you.
Biopsy
If your doctor at Memorial Sloan-Kettering suspects that you have lung cancer, arrangements will be made to perform a biopsy. Performing a biopsy is the only way for your doctors to determine whether the suspicious growth is 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 the cancerous tissue.
Bronchoscopy
During a bronchoscopy, you will first be put under anesthesia. A physician then places 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, physicians can precisely remove samples outside the bronchial tubes.
Fine Needle Aspiration
If the suspicious growth cannot be reached by a bronchoscopy, your physician may recommend a needle biopsy. In this procedure, also called fine needle aspiration, the patient receives anesthesia and a needle is inserted through the skin directly into the suspicious spot, where it removes 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. 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.
The two most common types of non-small cell lung cancer are adenocarcinoma and squamous cell carcinoma. Approximately 5-10% of non-small cell lung cancers cannot be classified as one of these two types and are called large cell lung cancer, or undifferentiated lung cancer.
Understanding what type of cancer you have is important because each type responds differently to certain chemotherapy drugs.
Molecular Testing of the Tumor: The LC-MAP Program
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.
Under this program, called the Lung Cancer Mutation Analysis Project (LC-MAP), our pathologists analyze cells in your tissue sample for genetic mutations that are found only in the cells of certain subtypes of non-small cell lung cancer.
Knowing this information has become very important to planning treatment for patients with non-small cell lung cancer. Tumors in approximately 60 percent of patients with adenocarcinoma have been found to have a known mutation for which specific, personalized treatments are available, either using FDA-approved drugs or new experimental treatments being tested in Memorial Sloan-Kettering’s clinical trials. Because we now know that certain drugs are either more or less effective than others against tumors with these mutations, participating in the LC-MAP Program can help to determine which therapies will be most effective for you.
When enough tumor sample is still available after the type of non-small cell lung cancer is determined, Memorial Sloan-Kettering pathologists use the remainder to check for genetic abnormalities such as EGFR (Epidermal Growth Factor Receptor) mutations and EML4-ALK rearrangements. If not enough tissue remains, you may be asked to undergo another biopsy. If enough tissue remains after these tests, we will ask your permission to test for other mutations that could help your doctor decide if a clinical trial of an experimental treatment might be an option for you.
Because these genetic changes do not occur in squamous cell carcinoma, our doctors do not typically recommend molecular testing for people with this type of non-small cell lung cancer.
Learn more about personalized medicine at Memorial Sloan-Kettering.
Staging: Determining Where the Lung Cancer Has Spread
If the pathologist determines that you have non-small cell lung cancer, the next step it to identify whether it has spread, or metastasized, to other parts of the body. To do so, 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, we 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. There are 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).
The stage is based on the location(s) of the tumors at the time the cancer is first discovered and never changes.
