Adenocarcinoma of the lung is a type of lung cancer. It occurs when abnormal lung cells multiply out of control and form a tumor. Eventually, tumor cells can spread (metastasize) to other parts of the body including the:
Compared with other types of lung cancer, adenocarcinoma is more likely to be contained in one area. If it is truly localized, it may respond to treatment better than other lung cancers.
Adenocarcinoma is the most common form of lung cancer. It's generally found in smokers. However, it is the most common type of lung cancer in nonsmokers. It is also the most common form of lung cancer in women and people younger than 45.
As with other forms of lung cancer, your risk of adenocarcinoma increases if you:
All lung cancers, including adenocarcinoma, have similar symptoms. They include:
If the cancer has spread beyond the lungs, it can cause other symptoms. For example, you may have bone pain if it has spread to your bones.
Many of these symptoms can be caused by other conditions. See your doctor if you have symptoms so that the problem can be diagnosed and properly treated.
Your doctor will start by taking your health history. He or she will ask about your smoking habits and whether you live with a smoker. Your doctor also will ask whether you may have been exposed to asbestos or other cancer-causing agents at work.
Next, he or she will order imaging tests to check your lungs for masses. In most cases, a chest X-ray will be done first. If the X-ray shows anything suspicious, a computed tomography (CT) scan will be done. As the scanner moves around you, it takes many pictures. A computer then combines the images. This creates a more detailed image of the lungs, allowing doctors to confirm the size and location of a mass or tumor.
You may also have a magnetic resonance imaging (MRI) scan or a positron emission tomography (PET) scan. MRI scans provide detailed pictures of the body's organs, but they use radio waves and magnets to create the images, not X-rays. PET scans look at the function of tissue rather than anatomy. Lung cancer tends to show intense metabolic activity on a PET scan. Some medical centers offer combined PET-CT scanning.
If cancer is suspected based on these images, more tests will be done to make the diagnosis, determine the type of cancer, and see if it has spread. These tests may include the following:
After the cancer has been diagnosed, it is assigned a "stage." The stage indicates the tumor's size and how far it has spread. Stages I through III are further divided into "A" and "B" categories. Stage I tumors are small and have not invaded surrounding tissues. Stage II and III tumors have invaded surrounding tissues and/or organs and have spread to lymph nodes. Stage IV tumors have spread beyond the chest.
Adenocarcinoma of the lung will continue to grow and spread until it is treated.
To reduce your risk of adenocarcinoma and other forms of lung cancer:
Treatment depends on the cancer's stage as well as the patient's condition, lung function, and other factors. (Some patients may have other lung conditions, such as emphysema or COPD -- chronic obstructive pulmonary disease.) If the cancer has not spread, surgery is usually the treatment of choice. There are three types of surgery:
Lymph nodes are also removed and examined to see if the cancer has spread.
Some surgeons use video-assisted thoracoscopy (VATS) to remove small, early-stage tumors, especially if the tumors are near the outer edge of the lung. (VATS can also be used to diagnose lung cancer.) Because the incisions for VATS are small, this technique is less invasive than a traditional "open" procedure.
Because surgery will remove part or all of a lung, breathing may be more difficult afterwards, especially in patients with other lung conditions (emphysema, for example). Doctors can test lung function prior to surgery and predict how it might be affected by surgery.
Depending on how far the cancer has spread, treatment may include chemotherapy (the use of anticancer drugs) and radiation therapy. These may be given before and/or after surgery.
When the tumor has spread significantly, chemotherapy may be recommended to slow its growth, even if it cannot cure the disease. Chemotherapy has been shown to ease symptoms and prolong life in cases of advanced lung cancer.
Radiation therapy can relieve symptoms, too. It is often used to treat lung cancer that has spread to the brain or bones and is causing pain. It can also be used alone or with chemotherapy to treat the lung cancer that is confined to the chest.
People who may not withstand surgery due to other serious medical problems may receive radiation therapy, with or without chemotherapy, to shrink the tumor.
In specialized cancer centers, cancerous tissue may be tested for specific genetic abnormalities (mutations). Doctors may then be able to treat the cancer with a "targeted therapy." These therapies can derail the cancer's growth by preventing or changing chemical reactions linked to particular mutations. For example, some target therapies prevent cancer cells from receiving chemical "messages" telling them to grow.
Knowing about specific genetic mutations can help predict which therapy will be best. This strategy can be especially helpful in certain patients, such as women with adenocarcinoma of the lung who have never smoked.Even after treatment has been completed, lung cancer patients must return for regular follow-up appointments. Even if the cancer was initially "cured," it can return months or even years later.
Call your doctor promptly if you have any symptoms of lung cancer, especially if you smoke or have been exposed to asbestos.
The outlook depends on the cancer's stage and the patient's overall health. In general, the prognosis is poor, especially if the lung cancer has spread beyond the chest or has invaded lymph nodes between the lungs.
Adenocarcinoma of the lung can only be cured if the entire tumor is removed surgically or destroyed with radiation. However, many lung cancers are diagnosed at a stage when this is not possible. Less than one-fifth of patients survive five years or longer.
National Cancer Institute (NCI)
U.S. National Institutes of Health
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American Cancer Society (ACS)
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American Lung Association
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New York, NY 10006
National Heart, Lung, and Blood Institute (NHLBI)
P.O. Box 30105
Bethesda, MD 20824-0105
U.S. Environmental Protection Agency (EPA)
Ariel Rios Building
1200 Pennsylvania Ave., N.W.
Washington, DC 20460