Overview of Lung Cancer
Lung cancer is the most frequently diagnosed cancer in the United States and the most frequent cause of death from cancer. However, new treatments for some types of lung cancer have given many lung cancer patients an improved outlook.
If you have been diagnosed with lung cancer, you probably have many questions about your disease, how it is likely to be treated, and what happens when treatment is completed. These treatment summaries for patients, which are based on the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines™), will help you understand the best available treatments for lung cancer. Talk to your doctors about these options so that together you can decide on a cancer treatment plan that is right for you.
Background
The lungs are a pair of cone-shaped organs that bring oxygen into the body as you breathe in, and release carbon dioxide when you breathe out. This oxygen is transported through the blood stream to cells throughout the body. The lungs are covered with layers of thin tissue called pleura. The left lung has two lobes, while the right lung (which is slightly larger) has three lobes. Air reaches the lungs through the windpipe (trachea). The trachea splits into an upside-down Y shape, and each arm, called a bronchus, brings air from the trachea into the lungs. Tiny air sacs called alveoli and small tubes called bronchioles make up the insides of the lungs. Chains of lymph nodes are found around the trachea and inside the lungs.
Lung cancer is often found in people who have smoked, but many people who have never smoked also develop the disease.
Types of Lung Cancer
Lung cancer is divided into two large groups, each of which represents different types of cells and has different treatment requirements. Separate treatment summaries are available for each of these types:
Non-small cell lung cancer is more common than small cell cancer, occurring in 85% of patients with lung cancer, while small cell only occurs in 15%.
These small cell and non-small cell lung cancers are further classified by the type of normal cell that has become cancerous. The most common types of non-small cell cancer are non-squamous cell (most common) and squamous cell.
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Adenocarcinomas: the most common type of non-squamous cell cancer, which means that they arise in glandular tissue that lines parts of the lungs and makes mucus and other substances
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Squamous cell cancer: arises in scalelike cells that cover the lining of the lungs
- Large cell: arises in several types of large cells in the lungs
The types of small cell lung cancer are:
- Small cell carcinoma (oat cell cancer)
- Combined small cell carcinoma
Diagnosing Lung Cancer
Early-stage lung cancer usually does not produce noticeable symptoms, although some people have a cough, wheezing, difficulty breathing, or chest discomfort. Most early-stage cancers are found when a patient has a chest x-ray or CT scan for another reason.
Symptoms that may indicate the presence of lung cancer include:
- Persistent cough
- Wheezing
- Chest discomfort
- Difficulty breathing
- Streaks of blood in sputum (mucus coughed up from the lungs)
- Hoarseness
- Loss of appetite
- Weight loss for no known reason
- Feeling very tired
To diagnose lung cancer, your doctor will usually start with tests, such as a chest x-ray or chest CT scan, to see whether you have a mass in your lungs.
If an abnormality is noted, the only sure way for your doctor to confirm or rule out cancer is to perform a biopsy, a procedure in which a sample of tissue from the suspicious area in the lung is removed and examined under a microscope to identify disease. A sample of tissue also may be taken from nearby lymph nodes.
Lymph node biopsy can be performed using different methods depending on the location and accessibility of your cancer. In some cases, the lymph nodes can be examined and removed using bronchoscopy. In this procedure a thin, tube-like instrument with a light and a lens and a cutting tool is inserted through the mouth, through your trachea (windpipe), and into your lungs. The doctor is able to look at your lungs and remove abnormal looking tissue for examination. In other cases, the lymph nodes are viewed using mediastinoscopy, a procedure in which an incision is cut above your breast bone and a thin, tube-like instrument with a light source, a lens, and a cutting tool is inserted so that your doctor can examine areas that are not accessible using a bronchoscope.
All of these samples are sent to a pathologist to determine whether the abnormal area is, in fact, cancer and, if so, the type of cancer and whether there is evidence that the cancer has spread to the lymph nodes. The pathology report also provides vital information about the extent of the cancer, in which area of the lung it began, and whether important tumor markers are present in or on the tumor cells. Because cancers with specific markers respond differently to different drugs, the presence or absence of certain tumor markers helps determine the type of treatment that is most likely to be effective for you.
Because many other types of cancer often spread to the lungs, the pathology report will also determine whether cancer started in the lungs or spread from another part of the body, in which case different treatment will be required.
If the biopsy indicates that you have lung cancer, tests will be performed to find out how aggressive your cancer is likely to be. These tests will help your doctor determine whether your tumor is confined to the area where it began (that is, it is localized) or has spread to other organs (metastasized). Your doctor also will take a detailed medical history and may request other tests to determine your overall health and whether certain treatments are appropriate for you.
These procedures provide information about your cancer that will be important in determining the stage of your disease. Knowing the stage of the disease, in turn, is vital to fashioning a treatment program for you that promises the best effects.
Staging
Staging is a formal system for identifying how localized or widespread your cancer is. For non-small cell lung cancer, the stages range from stage 0 (most localized) to stage IV (spread to distant organs in your body).
For small cell lung cancer, stages are described as:
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Limited-stage small cell lung cancer
: cancer is found in one lung, the tissues between the lungs, and nearby lymph nodes only.
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Extensive-stage small cell lung cancer: cancer has spread outside of the lung in which it began or to other parts of the body.
Staging is an important part of developing the best treatment plan for you. In general, the lower the stage of disease, the better the chance is that your cancer can be cured; the higher the stage, the less likely that your cancer can be cured. Staging is used both to help your doctors make treatment decisions and to provide you and your doctors with information about what typically happens to patients with cancers most like yours.
For a more detailed discussion of staging, see the Cancer Staging Guide.
Treatment of Lung Cancer
Treatment for lung cancer involves a number of specialists who plan and work as a team to coordinate a patient’s care, and often involves a combination of several approaches.
The effectiveness of treatment depends on the type of lung cancer, how localized your cancer is, whether or how far it has spread in your body, whether it is newly diagnosed or has recurred, and whether certain tumor markers have been found. Your treatment may involve several approaches, depending on the stage of your disease and the other indicators discussed above, the characteristics of your tumor, and your age and general health. Many of these approaches are meant to cure or slow the progression of your disease, while others are intended to reduce your symptoms (especially when your cancer has spread) and provide you with the best quality of life.
In general, treatments rely on the following approaches, often in combination:
- Surgery: removing diseased parts of your lung
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Radiation therapy (or radiotherapy): using high-energy beams to kill tumor cells; may be delivered by a machine outside the body
- Chemoradiation: using some chemotherapy drugs to make radiation therapy more effective. These drugs are also effective against small deposits of cancer too small to be seen by imaging outside the area of radiation therapy.
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Chemotherapy: using drugs to kill or slow the growth of cancer cells including any that have broken away from the original tumor
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Targeted therapy: using drugs directed toward certain markers on tumor cells or certain processes occurring in tumor cells.
In addition, some patients may need treatments to deal with the effects of the cancer. For example, it may be necessary to place a stent in the airways to help with breathing.
Your doctor should provide you with a written care plan explaining what treatments you will have, when they will occur, how often (if you will have chemotherapy or radiation), and what side effects you may experience. Some side effects can be anticipated, and you can have treatment to reduce their severity.
You will be asked to sign an informed consent document indicating that you have been told about your treatment and what to expect.
It is very important that you ask your doctor or nurse every question you have. Lung cancer and its treatments are complicated, and most patients have questions.
Clinical Trials
New therapies and combinations of therapies are enabling people with cancer to live longer, better-quality lives than ever before. You may want to find out whether you are eligible to participate in a clinical trial, in which new and experimental therapies are compared with standard treatments. More information is available in the Guide to Clinical Trials and Demystifying Common Clinical Trial Myths.
Prognosis for Lung Cancer
In determining a prognosis—the likely course or outcome of a disease and its treatment—a doctor may look at lung cancer survival statistics taken from studies of large groups of patients. However, such statistics:
- Are estimates only
- Can vary widely with each cancer stage
- Are sometimes based on older data that do not reflect recent advances in treatment options
- Cannot be used to precisely predict your survival
Your individual prognosis will be affected by many factors, including:
- Your age
- Your overall health
- The risk category of your cancer
- Your response to the treatment(s) being used
Life After Treatment
When your therapy is completed, you will need to see your doctor for follow-up visits at regular intervals to ensure that you remain healthy and that any long-term effects of cancer or its treatment can be addressed.