Lung Cancer Tumor Markers:
CEA (carcinoembryonic antigen)
CYFRA 21-1 (cytokeratin 19 fragment)
Diagnostic Strategy Based on Preoperative Serum CEA Levels in Clinical Stage
Lung cancer is not just one disease but rather a group of diseases. All forms of cancer cause cells in the body to change and grow out of control. Most types of cancer cells form a lump or mass called a tumor. Cells from the tumor can break away and travel to other parts of the body where they can continue to grow. This spreading process is called metastasis. When cancer spreads, it is still named after the part of the body where it started. For example, if breast cancer spreads to the lungs, it is still breast cancer, not lung cancer. Another word for cancerous is malignant, so a cancerous tumor is referred to as malignant. But not all tumors are cancer. A tumor that is not cancer is called benign. Benign tumors do not grow and spread the way cancer does. They are usually not a threat to life. A few cancers, such as blood cancers (leukemia), do not form a tumor. Most cancers are named after the part of the body where the cancer first starts. Lung cancer begins in the lungs. The lungs are two sponge-like organs in the chest. The right lung has three sections, called lobes. The left lung has two lobes. It is smaller because the heart takes up more room on that side of the body. The lungs bring air in and out of the body, taking in oxygen and getting rid of carbon dioxide gas, a waste product. The lining around the lungs, called the pleura, helps to protect the lungs and allows them to move during breathing. The windpipe (trachea) brings air down into the lungs. It divides into tubes called bronchi, which divide into smaller branches called bronchioles. At the end of these small branches are tiny air sacs known as alveoli. Most lung cancers start in the lining of the bronchi but they can also begin in other areas such as the trachea, bronchioles, or alveoli. Lung cancer often takes many years to develop. Once the lung cancer occurs, cancer cells can break away and spread to other parts of the body. Lung cancer is a life- threatening disease because it often spreads in this way before it is found. Lung cancer is the leading cause of cancer death for both men and women. During the year 2000 there will be about 164,100 new cases of lung cancer in this country. About 156,900 people will die of lung cancer: about 89,300 men and 67,600 women. More people die of lung cancer than of colon, breast, and prostate cancers combined. Lung cancer is fairly rare in people under the age of 40. The average age of people found to have lung cancer is 60. If lung cancer is found and treated by surgery early, before it has spread to lymph nodes or other organs, the five-year survival rate is about 42%. However, few lung cancers are found at this early stage. The five-year survival rate for all stages of lung cancer combined was 14% in 1995, the last year for which we have national data. A risk factor is something that increases a person's chance of getting a disease. Some risk factors, like smoking, can be controlled. Others, such as a person's age, can't be changed. Smoking is by far the leading risk factor for lung cancer. More than 8 out of 10 lung cancers are thought to result from smoking. The longer a person has been smoking, and the more packs per day smoked, the greater the risk. If a person stops smoking before lung cancer develops, the lung tissue slowly returns to normal. Stopping smoking at any age lowers the risk of lung cancer. Cigar and pipe smoking are almost as likely to cause lung cancer as cigarette smoking. There is no evidence that smoking low tar cigarettes reduces the risk of lung cancer. Nonsmokers who breathe the smoke of others also increase their risk of lung cancer. Non- smoking spouses of smokers, for example, have a 30% greater risk of developing lung cancer than do spouses of nonsmokers. Workers exposed to tobacco smoke in the workplace are also more likely to get lung cancer. There are other risk factors for lung cancer besides smoking. People who work with asbestos have a higher risk of getting lung cancer. If they also smoke, the risk is greatly increased. The type of lung cancer linked to asbestos, mesothelioma, often starts in the pleura. This type of cancer is covered in a separate American Cancer Society document. Although asbestos was used for many years, the government has now nearly stopped its use in the workplace and in home products. Besides smoking and asbestos, there are a few other risk factors for lung cancer. These include certain cancer-causing agents in the workplace, radon gas, and lung scarring from some types of pneumonia. Also, people who have had lung cancer in the past have a higher chance of having it again and, as mentioned earlier, the risk of lung cancer increases with age. Some studies have shown that the lung cells of women who smoke may develop cancer more easily than those of men. Clearly, the best way to prevent lung cancer is not to smoke or be around those who do. Young people should not start smoking, and those who already smoke should quit. Everyone, especially babies and children, should be protected from breathing in other people's smoke. While some people believe that air pollution is a major cause of lung cancer, the truth is that air pollution only slightly increases the risk. Smoking is by far the more important cause. Even so, some people who have never smoked or worked with asbestos still get lung cancer. Since we do not know why this happens, there is no sure way to prevent it. Since most people with early lung cancer do not have any symptoms, only about 15% of lung cancers are found in the early stages. Although most lung cancers do not cause symptoms until they have spread, you should report any of the following symptoms to your doctor right away. Often these problems are caused by some other condition, but if lung cancer is found, prompt treatment could extend your life and relieve symptoms. A cough that does not go away Chest pain, often made worse by deep breathing Hoarseness Weight loss and loss of appetite Bloody or rust-colored sputum (spit or phlegm) Shortness of breath Fever without a known reason Recurring infections such as bronchitis and pneumonia New onset of wheezing When lung cancer spreads to distant organs, it may cause: Bone pain Weakness or numbness of the arms or legs, dizziness Yellow coloring of the skin and eyes (jaundice) Masses near the surface of the body, caused by cancer spreading to the skin or to lymph nodes in the neck or above the collarbone Less often, there are some other clusters of symptoms (called syndromes) that can point to a possible lung cancer. Lately, some new tests to find lung cancer early have been developed. These tests are still being studied and are not yet used on a regular basis. If there is a reason to suspect you may have lung cancer, the doctor will use one or more methods to find out if the disease is really present. In addition, a biopsy of the lung tissue will confirm the diagnosis of cancer and also give valuable information that will help in making treatment decisions. If these tests find lung cancer, more tests will be done to find out how far the cancer has spread. After taking your medical history and doing a physical exam the doctor might want to do some of the following: Imaging tests: these tests use x- rays, magnetic fields, sound waves or radioactive substances to create pictures of the inside of the body. Some of the imaging tests used to find lung cancer and to see where in the body it may have spread include x-rays, CT scan (computed tomography), MRI (magnetic resonance imaging), PET (positron emission tomography) scans, and bone scans. Sputum cytology: a sample of phlegm (spit) is looked at under a microscope to see if cancer cells are present. Needle biopsy: a needle is placed into the tumor to remove a piece of tissue. The tissue is looked at in the lab to see if cancer cells are present. Bronchoscopy: a lighted, flexible tube is passed through the mouth into the bronchi. This test can help find tumors or it can be used to take samples of tissue or fluids to see if cancer cells are present. Mediastinoscopy: with the patient asleep, tissue samples are taken from the lymph nodes along the windpipe through a small hole cut into the neck. Again, looking at the tissue under a microscope can show if cancer cells are present. Bone marrow biopsy: a needle is used to remove a small piece of bone, usually from the back of the hip bone. The sample is checked for cancer cells. Blood tests: certain blood tests are often done to help see if the lung cancer has spread to the liver or bones. There are two major types of lung cancer. The first is small cell lung cancer, or SCLC. The other is non- small cell lung cancer, or NSCLC. If the cancer has features of both types, it is called mixed small cell/large cell cancer. Small cell lung cancer accounts for about 20% of all lung cancers. Although the cancer cells are small, they can multiply quickly and form large tumors. The tumors can spread to the lymph nodes and to other organs such as the brain, the liver, and the bones. Small cell lung cancer is usually caused by smoking. Other names for small cell lung cancer are oat cell cancer and small cell undifferentiated carcinoma. Non-small cell lung cancer is the most common type of lung cancer, accounting for almost 80% of lung cancers. There are three subtypes within this group. Some types grow more quickly than others. Ask your doctor to explain which of these you have. There are a few other rare types of lung cancer not covered in this document. Staging is the process of finding out how far the cancer has spread. This is very important because your treatment and the outlook for your recovery depend on the stage of your cancer. There are different staging systems for small cell and non-small cell lung cancer. Small cell lung cancer staging For small cell lung cancer a two-stage system is most often used. These are limited stage and extensive stage. Limited stage usually means that the cancer is only in one lung and in lymph nodes on the same side of the chest. If the cancer has spread to the other lung, to lymph nodes on the other side of the chest, or to distant organs, it is called extensive. Small cell lung cancer is staged in this way because it helps to determine the best treatment for each group. Many people with small cell lung cancer will already have extensive disease when it is found. The staging system most often used for non-small cell lung cancer is the TNM system, also known as the American Joint Committee on Cancer (AJCC) system. T stands for tumor (its size and how far it has spread within the lung and to nearby organs) N stands for spread to lymph nodes M stands for metastasis (spread to distant organs) All of this information is combined and a stage is assigned. The stages are described using Roman numerals 0-IV (1-4). In general, the lower the number, the less the cancer has spread. A higher number, such as stage IV (4), means a more serious cancer. After looking at your test results, the doctor will tell you the stage of your cancer. Be sure to ask your doctor to explain your stage in a way you understand. This will help you both decide on the best treatment for you. There is a lot for you to think about when choosing the best way to treat or manage your cancer. There may be more than one treatment to choose from. You may feel that you need to make a decision quickly. But give yourself time to absorb the information you have learned. Talk to your doctor. Look at the list of questions at the end of this piece to get some ideas. Then add your own. You may want to get a second opinion. Your doctor should not mind your doing this. In fact, some insurance companies require you to get a second opinion. You may not need to have tests done again since the results can often be sent to the second doctor. If you are in an HMO (health maintenance organization), find out about their policy concerning second opinions. The treatment options for lung cancer are surgery, radiation therapy, and chemotherapy, either alone or in combination, depending on the stage of the tumor. Depending on the type and stage of the cancer, surgery may be used to remove the tumor and some of the lung tissue around it. If a lobe (section) of the lung is removed, the surgery is called a lobectomy. Removing only part of the lobe is called a wedge resection. If the entire lung is removed, the surgery is called a pneumonectomy. These operations are done with the patient asleep. A hospital stay of one or two weeks is usually needed. There will be some pain after the surgery because the surgeon has to cut through the ribs to get to the lungs. People whose lungs are in good condition (other than the cancer) can often return to normal activities after a lobe or even an entire lung is removed. However, if they also have diseases such as emphysema or chronic bronchitis (common among heavy smokers), then they may have long-term shortness of breath. For people who can't have the usual surgery because of lung disease or other medical problems, or because the cancer is widespread, other types of surgery (for example, laser surgery) can be done to relieve symptoms. Chemotherapy refers to the use of drugs to kill cancer cells. Usually the drugs are given into a vein or by mouth. Once the drugs enter the bloodstream, they spread throughout the body. Often several drugs are given at the same time. Depending on the type and stage of lung cancer, chemotherapy may be given as the main treatment or in addition to surgery. Chemotherapy can have some side effects. These side effects will depend on the type of drugs given, the amount taken, and how long treatment lasts. Common side effects could include nausea and vomiting, loss of appetite, temporary hair loss, mouth sores, an increased risk of infections, and fatigue. Anyone who has problems with side effects should talk with their doctor or nurse as there are often ways to help. Radiation therapy is treatment with high energy rays (such as x-rays) to kill or shrink cancer cells. The radiation may come from outside the body (external radiation) or from radioactive materials placed directly in the tumor (internal or implant radiation). External radiation is the type most often used to treat lung cancer. Radiation is sometimes used as the main treatment of lung cancer, for example, for those people who may not be healthy enough to have surgery. For other patients, radiation might be used after surgery to kill small areas of cancer that can't be seen and removed during surgery. Radiation can also be used to relieve symptoms such as pain, bleeding, and trouble swallowing. Side effects of radiation therapy could include mild skin problems, nausea, vomiting, and tiredness. Often these go away after a short while. Chest radiation may cause lung damage and difficulty breathing. Side effects of radiation therapy to the brain (to treat metastasis) usually become most serious one or two years after treatment, and include headaches and trouble with thinking. Be sure to talk with your doctor if you have any side effects. Studies of new treatments in patients are known as clinical trials. A clinical trial is only done when there is some reason to believe that the treatment being studied may be of value to the patient. The main questions the researchers want to answer are: Does this treatment work? Does it work better than the one we're now using? What side effects does it cause? Do the benefits outweigh the risks? Which patients are most likely to find this treatment helpful? During your course of treatment, your doctor may suggest that you look into a clinical trial. This does not mean that you are being asked to be a human guinea pig. Nor does it mean that your case is hopeless. However, there are some risks. No one knows in advance if the treatment will work or exactly what side effects will occur. That's what the study is designed to find out. Keep in mind that standard treatments, too, can have side effects. Clinical trials are carried out in steps called phases. Each phase is designed to answer certain questions. Ask your doctor if there is a clinical trial that might be right for you. Then learn all you can about that trial. Because you volunteer to take part in a clinical trial, you can leave the trial at any time. As you cope with cancer and cancer treatment, you need to have honest, open discussions with your doctor. You should feel free to ask any question that's on your mind, no matter how small it might seem. Here are some questions you might want to ask. Be sure and add your own. Would you please write down the exact type of lung cancer I have? Has my cancer spread? What is the stage of my cancer and what does that mean in my case? What treatment choices do I have? What do you suggest and why? What is the goal of this treatment? What risks or side effects are there to the treatment you suggest? If I will lose my hair, what can I do about it? Based on what you've learned about my cancer, how long do you think I'll survive? What are the chances of the cancer coming back after treatment? What should I do to get ready for treatment? Remember that your body is unique, and so are your emotional needs and your personal circumstances. In some ways, your cancer is like no one else's. No one can predict how your cancer will respond to treatment. Statistics can paint an overall picture, but you may have special strengths such as a healthy immune system, a strong family support system, or a deep spiritual faith. All of these have an impact on how you cope with cancer. Cancer treatment can make you feel tired. Give some time to recover. Don't feel the need to rush back to work or resume all of your normal activities right away. The doctor will let you know what follow-up tests need to be done and when. Chest x-rays and blood tests may be done to see if the cancer has come back or if a new tumor has formed. Be sure to report any new or recurring symptoms to the doctor right away. Even after lung cancer has developed, it is very important to quit smoking. Quitting helps improve appetite and overall health and can reduce the chance of a new cancer. Ask your doctor or nurse for ideas about how to quit smoking. Do as much as you can to stay healthy and active. Eat a balanced diet of healthy foods, including plenty of fruits, vegetables, and whole grains. Once you get your strength back, try to exercise a few hours each week. Check with the doctor before you start an exercise program. The doctor can suggest the types of exercise that are right for you. The doctor or nurse can suggest other resources that might help you during your recovery from treatment. There are many support groups that provide emotional support, friendship, and understanding.