The lungs are the two organs located beneath the rib cage that provide life-sustaining oxygen throughout the body. They are neither symmetrical nor functionally identical, with the left lung consisting of two lobes and the right three. Lung cancer begins when cells of a lung become abnormal and begin growing out of control. When the abnormal cancer cells grow, they can form into a tumor and even spread to other areas of the body (metastasize).
Review this section's important information about lung cancer diagnosis, staging, and treatment options, as well as lung cancer patient and survivor resources as you prepare for an appointment with your oncologist. After reviewing these sections, ask your cancer care team any additional questions that you may have about your individual situation.
Types of Lung Cancer
Lung cancer is designated by two types:
- Small Cell Lung Cancer (SCLC)
- Non-Small Cell Lung Cancer (NSCLC)
Both small cell lung cancer and non-small cell lung cancer are named for the kinds of cells found in the cancer and how the cells appear when viewed under a microscope.
Small Cell Lung Cancer
The two general types of small cell lung cancer include:
- Small cell carcinoma (oat cell cancer)
- Combined small cell carcinoma
Smoking tobacco is the major risk factor for developing small cell lung cancer.
Non-Small Cell Lung Cancer
The three main types of non-small cell lung cancer include:
- Squamous cell carcinoma (epidermoid carcinoma)
- Large cell carcinoma
- Adenocarcinoma
Other less common types of non-small cell lung cancer are pleomorphic, carcinoid tumor, salivary gland carcinoma, and unclassified carcinoma.
Smoking can increase the risk of developing non-small cell lung cancer.
Diagnosis
Tests and procedures that examine the lungs are used to detect, diagnose, and also stage all forms of lung cancer.
Small Cell Lung Cancer
Tests and procedures used in diagnosis might include:
- Chest x-ray: An x-ray of the organs and bones inside the chest. An x-ray is a type of energy beam that can go through the body and onto film, making a picture of areas inside the body.
- Physical body exam and history: Check general signs of health, including possible signs of disease such as lumps or anything else that seems unusual. A history of the patient’s health habits and past illnesses and treatments will also be taken.
- CT Scan (CAT scan) of the brain, chest, and abdomen: A series of detailed pictures of areas inside the body, taken from different angles. The pictures are made by a computer linked to an x-ray machine. A dye may be injected into a vein or swallowed to help the organs or tissues show more clearly. This procedure is also called computed tomography, computerized tomography, or computerized axial tomography.
- PET Scan (positron emission tomography scan): A small amount of radioactive glucose (sugar) is injected into a vein, which aims to find malignant tumor cells in the body. The PET scanner rotates around the body and makes a picture of where glucose is being used in the body. Malignant tumor cells show up brighter in the picture because they are more active and take up more glucose than do normal cells.
- Sputum Cytology: A microscope is used to check for cancer cells in the sputum (mucus coughed up from the lungs).
- Bronchoscopy: Uses a bronchoscope, which is a thin, tube-like instrument with a light and a lens for viewing, that is inserted through the nose or mouth into the trachea and lungs to look inside the trachea and large airways in the lung for abnormal areas. A bronchoscope may also have a tool to remove tissue samples, which are checked under a microscope for signs of cancer.
- Fine-needle aspiration (FNA) biopsy of the lung: A CT scan, ultrasound, or other imaging procedure is used to locate the abnormal tissue or fluid in the lung, and then a small incision may be made in the skin where the biopsy needle is inserted into the abnormal tissue or fluid. A sample is removed with the needle and sent to the laboratory. A pathologist then views the sample under a microscope to look for cancer cells. A chest x-ray is performed afterward to ensure that no air is leaking from the lung into the chest.
- Thoracoscopy: A surgical procedure to check for abnormal areas by looking at the organs inside the chest. A thoracoscope is a thin, tube-like instrument with a light and a lens for viewing. Typically, an incision (cut) is made between two ribs to insert a thoracoscope into the chest for viewing or for using a tool to remove tissue or lymph node samples that are then checked under a microscope for signs of cancer.
In some cases, this procedure is used to remove part of the esophagus or lung. If certain tissues, organs, or lymph nodes can’t be reached, a thoracotomy may involve a larger incision between the ribs to open the chest.
- Thoracentesis is using a needle to remove fluid from the space between the lining of the chest and the lung. A pathologist then views the fluid under a microscope to look for cancer cells.
Non-Small Cell Lung Cancer
Some of the tests used to diagnose non-small cell lung cancer are also used to stage the disease. Other tests and procedures that may be used during diagnosis include the following:
- Laboratory tests: Includes testing samples of tissue, blood, urine, or other substances in the body. These tests help to diagnose disease, plan and check treatment, or monitor the disease over time.
- MRI (magnetic resonance imaging): A procedure that uses a magnet, radio waves, and a computer to make a series of detailed pictures of areas inside the body, such as the brain. This procedure is also called nuclear magnetic resonance imaging (NMRI).
- Radionuclide bone scan: Used to check if there are rapidly dividing cells, such as cancer cells, in the bone. A very small amount of radioactive material is injected into a vein and travels through the bloodstream. The radioactive material collects in the bones and is detected by a scanner.
- Endoscopic ultrasound (EUS): A procedure in which an endoscope that is inserted into the body. A probe at the end of the endoscope is used to bounce high-energy sound waves (ultrasound) off internal tissues or organs and make echoes. The echoes form a picture of body tissues called a sonogram. This procedure is also called endosonography. EUS may be used to guide fine needle aspiration (FNA) biopsy of the lung, lymph nodes, or other areas.
Staging
Cancer staging is the process of gathering information to determine the location and extent of the cancer and if it has spread to other parts of the body. The information gathered from the staging process determines the stage of the disease, which assists the doctor in understanding the seriousness of the cancer, providing an optimal treatment plan, identifying potential clinical trials for viable treatment options, and even providing chances of survival.
After determining a diagnosis of small cell or non-small cell lung cancer, additional testing determines if the cancer cells have spread within the chest or to other parts of the body. Information gathered determines the stage of the disease and the treatment plan.
Small Cell Lung Cancer
Additional tests and procedures that may be used in the staging process include:
- Laboratory tests
- Bone marrow aspiration and biopsy: The removal of bone marrow, blood, and a small piece of bone by inserting a hollow needle into the hipbone or breastbone. A pathologist views the bone marrow, blood, and bone under a microscope to look for signs of cancer.
- MRI (magnetic resonance imaging)
- Endoscopic ultrasound (EUS)
- Lymph node biopsy: The removal of all or part of a lymph node. A pathologist views the tissue under a microscope to look for cancer cells.
- Radionuclide bone scan
Stages of Small Cell Lung Cancer:
- Limited-Stage Small Cell Lung Cancer: In limited-stage small cell lung cancer, cancer is found in one lung, the tissues between the lungs, and nearby lymph nodes only.
- Extensive-Stage Small Cell Lung Cancer: In extensive-stage small cell lung cancer, cancer has spread outside of the lung in which it began or to other parts of the body.
Non-Small Cell Lung Cancer
Additional tests and procedures that may be used in the staging process include:
- Lymph node biopsy
- Mediastinoscopy: A surgical procedure to look at the organs, tissues, and lymph nodes between the lungs for abnormal areas. An incision (cut) is made at the top of the breastbone, and a mediastinoscope is inserted into the chest. A mediastinoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue or lymph node samples, which are checked under a microscope for signs of cancer.
- Anterior mediastinotomy: A surgical procedure to look at the organs and tissues between the lungs and between the breastbone and heart for abnormal areas. This is also called the Chamberlain procedure.
Stages of Non-Small Cell Lung Cancer:
- Occult (hidden) stage: In the occult (hidden) stage, cancer cells are found in sputum (mucus coughed up from the lungs), but no tumor can be found in the lung by imaging or bronchoscopy, or the primary tumor is too small to be checked.
- Stage 0 (Carcinoma in Situ): In stage 0, abnormal cells are found in the innermost lining of the lung. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ (localized).
- Stage I: Cancer has formed. Stage I is divided into stages IA and IB:
- Stage IA: The tumor is in the lung only and is 3 centimeters or smaller.
- Stage IB: One or more of the following is true:
- The tumor is larger than 3 centimeters.
- Cancer has spread to the main bronchus of the lung and is at least 2 centimeters from the carina (where the trachea joins the bronchi).
- Cancer has spread to the innermost layer of the membrane that covers the lungs.
- The tumor partly blocks the bronchus or bronchioles and part of the lung has collapsed or developed pneumonitis (inflammation of the lung).
- Stage II: Stage II is divided into stages IIA and IIB:
- Stage IIA: The tumor is 3 centimeters or smaller and cancer has spread to nearby lymph nodes on the same side of the chest as the tumor.
- Stage IIB:
- Cancer has spread to nearby lymph nodes on the same side of the chest as the tumor and one or more of the following is true:
- The tumor is larger than 3 centimeters.
- Cancer has spread to the main bronchus of the lung and is 2 centimeters or more from the carina (where the trachea joins the bronchi).
- Cancer has spread to the innermost layer of the membrane that covers the lungs.
- The tumor partly blocks the bronchus or bronchioles and part of the lung has collapsed or developed pneumonitis (inflammation of the lung).
OR
- Cancer has not spread to lymph nodes and one or more of the following is true:
- The tumor may be any size, and cancer has spread to the chest wall, or the diaphragm, or the pleura between the lungs, or membranes surrounding the heart.
- Cancer has spread to the main bronchus of the lung and is no more than 2 centimeters from the carina (where the trachea meets the bronchi), but has not spread to the trachea.
- Cancer blocks the bronchus or bronchioles, and the whole lung has collapsed or developed pneumonitis (inflammation of the lung).
- Stage III: Stage III is divided into stages IIIA and IIIB:
- Stage IIIA: cancer has spread to lymph nodes on the same side of the chest as the tumor. The tumor may be any size. One or more of the following is true:
- Cancer may have spread to the main bronchus, the chest wall, the diaphragm, the pleura around the lungs, or the membrane around the heart, but has not spread to the trachea.
- Part or all of the lung may have collapsed or developed pneumonitis (inflammation of the lung).
- Stage IIIB, the tumor may be any size and has spread:
- To lymph nodes above the collarbone or in the opposite side of the chest from the tumor; and/or
- To any of the following:
- Heart
- Major blood vessels that lead to or from the heart
- Chest wall
- Diaphragm
- Trachea
- Esophagus
- Sternum (chest bone) or backbone
- More than one place in the same lobe of the lung
- The fluid of the pleural cavity surrounding the lung
- Stage IIIA: cancer has spread to lymph nodes on the same side of the chest as the tumor. The tumor may be any size. One or more of the following is true:
- Stage IV: In Stage IV, cancer may have spread to lymph nodes and has spread to another lobe of the lungs or to other parts of the body, such as the brain, liver, adrenal glands, kidneys, or bone.
Treatment Options
Small Cell Lung Cancer
Different types of treatment are available for patients with small cell lung cancer. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials (potential new treatments).
A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial, although some are open only to patients who have not started treatment.
Five types of standard small cell cancer treatment include:
1. Surgery
Surgery may be used if the cancer is found in one lung and in nearby lymph nodes only. However, this type of lung cancer is usually found in both lungs; therefore, surgery alone is not often used.
Even if the doctor removes all the cancer that can be seen at the time of the operation, some patients may be given chemotherapy or radiation therapy after surgery to kill any cancer cells that may remain. Treatment that is given after the surgery to lower the risk that the cancer will come back is called adjuvant therapy.
2. Chemotherapy
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. The way the chemotherapy is given depends upon the type and stage of the cancer being treated.
When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy).
When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy).
3. Radiation therapy
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. The way the a radiation therapy is given depends upon the type and stage of the cancer being treated.
There are two types of radiation therapies:
- External radiation therapy uses a machine outside the body to send radiation toward the cancer.
- Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. Prophylactic cranial irradiation (radiation therapy to the brain to reduce the risk that cancer will spread to the brain) may also be given.
4. Laser therapy
Laser therapy is a cancer treatment that uses a laser beam (a narrow beam of intense light) to kill the cancer cells.
5. Endoscopic stent placement
An endoscope is a thin, tube-like instrument used to look at tissues inside the body. An endoscope has a light and a lens for viewing and may be used to place a stent in a body structure to keep the structure open. Endoscopic stent placement can be used to open an airway blocked by abnormal tissue.
Non-Small Cell Lung Cancer
Depending on the stage of the non-small cell lung cancer, the treatment plan will be adjusted, below is an idea of what treatment plans may look like for each of the stages.
- Occult Non-Small Cell Lung Cancer treatment depends on where the cancer has spread. It can usually be cured by surgery.
- Stage 0 treatment may include:
- Surgery (wedge resection or segmental resection).
- Photodynamic therapy using an endoscope.
- Electrocautery, cryosurgery, or laser surgery using an endoscope.
- Stage I treatment may include:
- Surgery (wedge resection, segmental resection, sleeve resection, or lobectomy).
- External radiation therapy (for patients who cannot have surgery or choose not to have surgery).
- A clinical trial of surgery followed by chemoprevention.
- Stage II treatment may include:
- Surgery (wedge resection, segmental resection, sleeve resection, lobectomy, or pneumonectomy).
- External radiation therapy (for patients who cannot have surgery or choose not to have surgery).
- Surgery followed by chemotherapy.
- Stage III non-small lung cancer treatment is divided into Stage IIIA and Stage IIIB:
- Stage IIIA: Non-small cell lung cancer that can be removed with surgery may include surgery followed by chemotherapy.
- Non-small cell lung cancer that cannot be removed with surgery may include:
- Chemotherapy combined with radiation therapy.
- External radiation therapy alone (for patients who cannot be treated with combined therapy).
- Some Stage IIIA non-small cell lung tumors that have grown into the chest wall may be completely removed, and treatment of chest wall tumors may include:
- Surgery
- Surgery and radiation therapy
- Radiation therapy alone
- Chemotherapy combined with radiation therapy and/or surgery.
- Non-small cell lung cancer that cannot be removed with surgery may include:
- Stage IIIB treatment may include:
- Chemotherapy combined with external radiation therapy.
- External radiation therapy as palliative therapy, to relieve pain and other symptoms and improve the quality of life.
- Stage IIIA: Non-small cell lung cancer that can be removed with surgery may include surgery followed by chemotherapy.
- Stage IV treatment may include:
- External radiation therapy as palliative therapy, to relieve pain and other symptoms and improve the quality of life
- Combination chemotherapy
- Combination chemotherapy and targeted therapy
- Laser therapy and/or internal radiation therapy using an endoscope.
Follow-up Tests May be Needed
For both small cell lung cancer and non-small cell lung cancer, some of the tests that were done to diagnose the type or stage of lung cancer may need to be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change or stop treatment may be based on the results of these tests. This is sometimes called re-staging.
Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.