What is lung adenocarcinoma?
Lung adenocarcinoma is the most common kind of lung cancer both in smokers and non-smokers and in people under age 45. Adenocarcinoma accounts for about 30 percent of primary lung tumors in male smokers and 40 percent in female smokers. Among non-smokers, these percentages approach 60 percent in males and 80 percent in females. This disease also is more common among Asian populations.
Who is most likely to have lung adenocarcinoma?
Smoking frequently causes this type of cancer. Both how much and how long you smoke increase the chances of lung cancer. If you quit smoking, your risk decreases over time. Secondary risk factors include age, family history, and exposure to secondhand smoke, mineral and metal dust, asbestos, or radon.
What characterizes lung adenocarcinoma?
This type of non-small cell lung cancer usually develops in the peripheral portion of the lungs. Lung adenocarcinoma cells form recognizable glandular patterns. This type of cancer is more likely than other kinds of lung cancer to be contained in one area of the body. Slow growing, lung adenocarcinoma can take years to develop from a confined tumor to metastatic cancer. Symptoms develop slowly as well. They include coughing, shortness of breath, wheezing, chest pain, and bloody sputum. Sometimes, this illness may appear at first to be pneumonia or a collapsed lung.
What tests can help to identify lung adenocarcinoma?
The practical first steps are a thorough physical examination and the testing of a sample of sputum for bacteria, infectious organisms, and cancer cells. If the sputum test does not provide a definite diagnosis, your primary care physician may prescribe further tests, which may include a chest x-ray or bronchoscopy. A chest x-ray can detect a mass in the lungs or enlarged lymph nodes in the chest. Bronchoscopy is an examination of the windpipe and lung branches with a flexible scope.
If it appears there may be a mass in your lungs, your primary care physician or cancer specialist may order a CT or MRI scan or a needle biopsy. CT (computed tomography) or MRI (magnetic resonance imaging) scans produce chest images that assist physicians to better determine the nature, position or extent of a mass. CT is also used to guide a needle biopsy, which gathers cell samples from a suspicious area using a slim, hollow needle attached to a syringe.
How does a pathologist diagnose lung adenocarcinoma?
Your pathologist reviews the results of the sputum sample or biopsy. Through this review, your pathologist is able to confirm a diagnosis of cancer.
What else does the pathologist look for?
Your pathologist may examine additional blood tests ordered by your primary care physician or specialist. These tests identify lung cancer markers—elements in the blood associated with lung cancer. Finding particular types of markers helps the pathologist determine the exact type of cancer. Also, if fluid has accumulated in the chest, a pathologist may examine a sample obtained through a procedure called thoracentesis in which a needle withdraws a fluid sample.
How do doctors determine what surgery or treatment will be necessary?
If cancer is found by the pathologist, your primary physician or specialist may order a bone scan to see if the cancer has spread into your bones. If the cancer has not spread, a procedure called mediastinoscopy may be recommended. In this procedure, a physician examines tissues and organs in the middle chest with an endoscope, which is a small, flexible device with a camera. The endoscope is inserted into the chest through a small incision at the top of the breastbone. Lymph nodes from the middle chest area are usually removed during this procedure. If the pathologist does not find cancer cells in these nodes, your primary care physician or specialist may recommend surgery.
After reviewing the results of all your tests and procedures, your pathologist assigns a pathologic stage to your lung cancer. Stage 1 lung adenocarcinomas are small and confined to the lungs, and stage 4 tumors have spread beyond tissues and organs near the lungs. Stages between 2 and 3 describe conditions in between these two extremes.
Once the stage has been determined, your primary care physician or cancer specialist will discuss treatment options with you. If the cancer is located only in the lungs, surgery is generally recommended. Common lung cancer surgical procedures include thoractomy (opening the chest wall) or median sternotomy (cutting through the breastbone) during which lung tissue, one lobe, or an entire lung will be removed, depending on the size of the tumor. Recently, surgeons have developed less-invasive procedures to remove cancerous tissue. Most appropriate for stage 1 and 2 cancers localized in the chest area, video-assisted thoracic surgery (VATS) enables surgeons to remove tissue through smaller incisions.
For aggressive and widespread tumors, physicians usually recommend chemotherapy and radiation therapy. Chemotherapy delivers drugs throughout the body, slows the cancer’s progression, and reduces pain. Chemotherapy can be used before and after surgery and can be combined with other treatments. Radiation therapy—pinpointed high-energy beams—can be used to shrink tumors or to destroy cancer cells that remain after surgery. This treatment is also used to relieve the symptoms of advanced lung cancer.
Clinical trails of new treatments for lung adenocarcinoma may be found at www.cancer.gov/clinicaltrials. These treatments are highly experimental in nature but may be the best option for advanced cancers.
What kinds of questions should I ask my doctors?
Ask any question you want. There are no questions you should be reluctant to ask. Here are a few to consider:
DEFINITION OF TERMS
Adenocarcinoma: A type of cancerous, or malignant, tumor that forms glandular structures.
Lobe: A spongy, saclike respiratory compartment in the lung that removes carbon dioxide from the blood and supplies it with oxygen. The right lung has three lobes and the left has two.
Malignant: Cancerous and capable of spreading.
Pathologist: A physician who examines tissues and fluids to diagnose disease in order to assist in making treatment decisions.
Biopsy: Removal of a tissue sample.
Sputum: Mucus coughed up from the lungs.
This information was developed by the College of American Pathologists’ Public Affairs Committee in conjunction with the College’s Cancer Committee and Council on Scientific Affairs. The College is providing this information to help you better understand your health. Ultimately any decisions you make about your health, however, should be between you and your doctor.