MesotheliomaLast Updated: January 21, 2010 This section has been reviewed and approved by the Cancer.Net Editorial Board, 11/09 Overview
Mesothelioma is a rare cancer that begins in the lining of the internal organs of the body. Approximately three-fourths of mesotheliomas begin in the lining surrounding the lungs, called pleural mesothelioma. While pleural mesothelioma does begin in the chest cavity, it does not start in the lungs, and it is often incorrectly grouped with lung cancer. Mesothelioma that begins in the tissue surrounding the abdominal area, called peritoneal mesothelioma, accounts for about 10% to 20% of mesotheliomas. The most rare type of mesothelioma begins in the lining around a man’s testicles, called the tunica vaginalis. There are three main types of mesothelioma: Epithelial type. The epithelial type accounts for 50% to 70% of people diagnosed with mesothelioma. It has the best prognosis (chance of recovery) because it grows slowly and is more likely to respond to treatment. Sarcoma type. The sarcoma type accounts for 7% to 20% of people diagnosed with mesothelioma and has a worse prognosis. Mixed type. The mixed type accounts for 20% to 35% of people diagnosed with mesothelioma and contains both epithelial and sarcoma types. This type of mesothelioma has an intermediate prognosis. Statistics It is estimated that 2,000 to 3,000 people are diagnosed with mesothelioma each year in the United States. Mesothelioma occurs more frequently in men, and three-fourths of people with mesothelioma are over age 65. While mesothelioma rates have increased in previous decades, they have since stabilized in the United States and may be decreasing. The five-year relative survival rate (percentage of people who survive at least five years after the cancer is detected, excluding those who die from other diseases) of people with mesothelioma is about 10%. The average survival for a person with mesothelioma is about one to two years because the cancer has often already grown and spread before it is diagnosed. However, cancer survival statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with mesothelioma. Because the survival statistics are measured in five-year intervals, they may not represent advances made in the treatment or diagnosis of this cancer. Also, survival rates differ from person to person. Some people live for many years with mesothelioma while others have a more aggressive type of disease. In particular, some patients with peritoneal mesothelioma have tumors that grow very slowly. Source: American Cancer Society Find out more about basic cancer terms used in this section. Risk Factors
A risk factor is anything that increases a person’s chance of developing cancer. Some risk factors can be controlled, such as smoking, and some cannot be controlled, such as age and family history. Although risk factors can influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and communicating them to your doctor may help you make more informed lifestyle and health-care choices. The following factors can raise a person’s risk of developing mesothelioma: Asbestos exposure. Between 70% to 80% of people diagnosed with mesothelioma have a history of asbestos exposure at work. Asbestos is a group of natural minerals found in the earth. Because of its strong, flexible fibers, asbestos was once commonly added to cement, insulation, roof shingles, and other products. People involved in the manufacturing of products containing asbestos or their installation and maintenance can breathe in or swallow the asbestos fibers. These fibers can also be carried in asbestos dust on clothing or personal items, exposing family members of the workers to potentially high levels of the minerals. Current safety regulations require people who work with asbestos to wear protective equipment and to shower and change clothes before leaving the workplace. Smoking. Smoking by itself does not increase the risk of mesothelioma, but the combination of smoking and asbestos exposure greatly increases the risk of certain types of cancer in the lung. Radiation exposure. Radiation exposure may cause mesothelioma. Zeolite exposure. Exposure to a type of mineral called zeolite may cause mesothelioma. Infection. Infection with certain viruses, such as the simian virus 40 (SV40), may be associated with mesothelioma, although this link has not been proven. Even though some people with mesothelioma have no known risk factors, many people who develop mesothelioma have been exposed to asbestos or chemicals. Therefore, it is important to always wear protective gear when working with asbestos. Symptoms
People with mesothelioma may experience the following symptoms. Sometimes, people with mesothelioma do not show any of these symptoms. Or, these symptoms may be caused by a medical condition that is not cancer. Often, symptoms of mesothelioma may not appear until years or even decades after asbestos exposure. If you are concerned about a symptom on this list, please talk to your doctor. If mesothelioma is in the lung area, called pleural mesothelioma, the symptoms may include:
If mesothelioma is in the abdominal area, called peritoneal mesothelioma, the symptoms may include:
General symptoms of mesothelioma may include:
Diagnosis
Doctors use many tests to diagnose cancer and determine if it has metastasized (spread). Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:
The diagnosis of mesothelioma is challenging. The diagnosis can be difficult to determine, or it can be confused with other diseases, such as lung cancer. Many people first notice symptoms of mesothelioma when they develop fluid in the space around the lungs (called pleural effusion) or in the abdomen. When this fluid is removed, it can be analyzed to see if there are cancer cells in it. However, testing this fluid is usually not the only test needed to diagnose the disease; a biopsy is also used to diagnose mesothelioma. Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. Other tests can suggest that cancer is present, but only a biopsy can make a definite diagnosis. The sample removed during the biopsy is analyzed by a pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease). A biopsy is usually needed to confirm a diagnosis of mesothelioma. Sometimes, a needle can be used to get a sample of the lining. More often the doctor removes a tissue sample by using a thin, lighted tube inserted through a small incision in the body. This is called a video thoracoscopy when used to get samples from inside the chest or a laparoscopy to get tissue samples from inside the abdomen. The following procedures may be used to help develop a treatment plan: Physical examination. A physical examination may include a medical history of the person and his or her family's past illnesses, a list of their risk factors (including asbestos exposure), and an examination for other signs of cancer. Lung function tests. Also called pulmonary function tests or PFTs, lung function tests evaluate how much air the lungs can hold, how quickly air can move in and out of the lungs, and how well the lungs add oxygen and remove carbon dioxide from the blood. X-ray. An x-ray is a picture of the inside of the body. An x-ray of the chest can sometimes help doctors determine if a person has mesothelioma and where it is located, but it is not the main way to diagnose mesothelioma. Computed tomography (CT or CAT) scan. A CT scan creates a three-dimensional picture of the inside of the body with an x-ray machine. A computer then puts these images into a detailed, cross-sectional view that shows abnormalities or tumors. Sometimes, a contrast medium (a special dye) is injected into a patient’s vein to provide better detail. Magnetic resonance imaging (MRI). An MRI uses magnetic fields, not x-rays, to produce detailed images of the body. A contrast medium may be injected into a patient’s vein to create a clearer picture. Positron emission tomography (PET) scan. A PET scan is a way to create pictures of organs and tissues inside the body. A small amount of a radioactive substance is injected into a patient’s body and absorbed by the organs or tissues being studied. This substance gives off energy that is detected by a scanner, which produces the images. Learn more about what to expect when having common tests, procedures, and scans. Find out more about common terms used during a diagnosis. Staging
Staging is a way of describing a cancer, such as where it is located, if or where it has spread, and if it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer's stage, so staging may not be complete until all the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis (chance of recovery). There are different stage descriptions for different types of cancers. This section on staging is for pleural mesothelioma. Currently, there is no standard staging system for peritoneal mesothelioma. One tool that doctors use to describe the stage is the TNM system. This system uses three criteria to judge the stage of the cancer: the tumor itself, the lymph nodes around the tumor, and if the tumor has spread to the rest of the body. The results are combined to determine the stage of cancer for each person. There are four stages for pleural mesothelioma: stages I through IV (one through four). The stage provides a common way of describing the cancer so doctors can work together to plan the best treatments. TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:
Tumor. Using the TNM system, the "T" plus a letter and/or number (0 to 4) is used to describe the stage of the tumor. Some stages are also divided into smaller groups that help describe the tumor in even more detail. This helps the doctor develop the best treatment plan for each patient. Specific tumor stage information is listed below: TX: The primary tumor cannot be evaluated. T0: There is no tumor. T1: The tumor has invaded the thin membrane that lines the lung and inner chest walls on one side of the body, called the ipsilateral pleura. T1a: The tumor involves the ipsilateral parietal pleura (the thin lining around the chest wall), with no involvement of the visceral pleura (the thin lining around the lung). T1b: The tumor has invaded the ipsilateral parietal pleura and the visceral pleura. T2: The tumor involves any of the ipsilateral pleural surfaces and invades either the diaphragm (the muscle that separates the chest cavity from the abdomen), or the lung. T3: The tumor involves any of the ipsilateral pleural surfaces, with at least one of the following: invasion of the membrane that surrounds the thorax, called the endothoracic fascia; invasion into the mediastinum (the area of the chest between the lungs); a single area of invasion into the muscles of the chest wall; or minimal invasion into the lining around the heart called the pericardium. T4: The tumor involves any of the ipsilateral pleural surfaces, with at least one of the following:
Node. The “N” in the TNM staging system stands for lymph nodes, the tiny, bean-shaped organs that help fight infection. Lymph nodes near the chest are called regional lymph nodes. Lymph nodes in other parts of the body are called distant lymph nodes. NX: The regional lymph nodes cannot be evaluated. N0 (N plus zero): Cancer has not spread to the regional lymph nodes. N1: Cancer has spread to the bronchopulmonary lymph nodes (located within the lungs) on one side of the body and/or hilar lymph node(s) (near the larger airways of the lungs). N2: Cancer has spread to the subcarinal lymph node(s) (surrounding the windpipe) and/or the mediastinal lymph node(s) (located in the center of the chest between the lobes of the lungs) on one side of the body, including the internal mammary lymph nodes (near the breast bone) on one side of the body and the peridiaphragmatic lymph nodes (surrounding the diaphragm). N3: Cancer has spread to the mediastinal lymph nodes on both sides of the body, the internal mammary lymph nodes, and/or supraclavicular lymph node(s) (above the collar bone) on one or both sides of the body. Distant metastasis. The “M” in the TNM system indicates whether the cancer has spread to other parts of the body. M0 (M plus zero): Cancer has not spread to other parts of the body. M1: Cancer has spread to other parts of the body. Cancer stage grouping Doctors assign the stage of the cancer by combining the T, N, and M classifications. Stage I: The tumor has invaded the ipsilateral parietal pleura, with or without involvement of the visceral pleura, but has not spread to the lymph nodes or other parts of the body (T1, N0, M0). Stage IA: The tumor has invaded the ipsilateral parietal pleura, without involvement of the visceral pleura, but has not spread to the lymph nodes or other parts of the body (T1a, N0, M0). Stage IB: The tumor has invaded the ipsilateral parietal pleura, with involvement of the visceral pleura, but has not spread to the lymph nodes or other parts of the body (T1b, N0, M0). Stage II: The tumor is defined as T2 (see above), and cancer has not spread to the lymph nodes or throughout the body (T2, N0, M0). Stage III: Any of the following conditions:
Stage IV: Any of the following conditions:
Recurrent: Recurrent cancer is cancer that comes back after treatment. It may return in the chest or in another part of the body. Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Seventh Edition (2010) published by Springer-Verlag New York, www.cancerstaging.net. Treatment
The treatment of mesothelioma depends on the size and location of the tumor, whether the cancer has spread, and the person’s overall health. In many cases, a team of doctors will work with the patient to determine the best treatment plan. This section outlines treatments that are the standard of care (the best treatments available) for this specific type of cancer. Patients are also encouraged to consider clinical trials as a treatment option when making treatment plan decisions. A clinical trial is a research study to test a new treatment to prove it is safe, effective, and possibly better than standard treatment. Your doctor can help you review all treatment options. For more information, visit the Clinical Trials section. For mesothelioma, there are three main types of treatment: surgery, radiation therapy, and chemotherapy. Descriptions of these treatment options are listed below. Surgery A surgical oncologist is a doctor who specializes in treating cancer using surgery. The type of surgery for mesothelioma depends on the stage and location of the cancer. Pleural mesothelioma. The surgeon may remove the affected lining around the lung in a procedure called a pleurectomy. Generally, the tumor cannot be completely removed with this procedure. A more aggressive surgery for pleural mesothelioma is called an extrapleural pneumonectomy. This is the removal of the lining of the lung, the entire lung, a portion of the diaphragm, and often a portion of the lining around the heart. This is a difficult surgery and is recommended only after the doctor has reviewed many factors, including the patient’s overall health and the stage of the disease. If the entire tumor cannot be removed, other treatments such as radiation therapy or chemotherapy may be recommended. Peritoneal mesothelioma. Patients with peritoneal mesothelioma may often have a surgery called a peritonectomy, which is the removal of the lining around the abdominal organs. Since patients with peritoneal mesothelioma often have tumors throughout the entire abdomen, it is difficult to remove all of them. The goal of surgery is to leave behind tumors that are as small as possible. After surgery, chemotherapy is often placed directly into the abdominal cavity, called intraperitoneal chemotherapy (see below). Learn more about cancer surgery. Radiation therapy Radiation therapy is the use of high-energy x-rays or other particles to kill cancer cells. A doctor who specializes in giving radiation therapy to treat cancer is called a radiation oncologist. The most common type of radiation treatment is called external-beam radiation, which is radiation given from a machine outside the body. When radiation treatment is given using implants, it is called internal radiation therapy or brachytherapy. Pleural mesothelioma. It is challenging to treat pleural mesothelioma with radiation because of the risk of damaging the lung. When one of the two lungs has been surgically removed, radiation therapy is often given to the chest cavity to lower the risk of the mesothelioma returning in the chest. For some patients, radiation may be given to a smaller area to help with symptoms such as pain. Peritoneal mesothelioma. For patients with peritoneal mesothelioma, radiation therapy can be used to treat the entire abdomen, but this often causes severe side effects, and is not commonly done. Side effects from radiation therapy include tiredness, mild skin reactions, upset stomach, and loose bowel movements. Most side effects go away soon after treatment is finished. Learn more about radiation therapy. Chemotherapy Chemotherapy is the use of drugs to kill cancer cells. Systemic chemotherapy is delivered through the bloodstream, targeting cancer cells throughout the body. Chemotherapy is given by a medical oncologist, a doctor who specializes in treating cancer with medication. Some people may receive chemotherapy in their doctor’s office; others may go to the hospital. A chemotherapy regimen (schedule) usually consists of a specific number of cycles given over a specific time. Pleural mesothelioma. The chemotherapy treatment best studied in mesothelioma is the combination of pemetrexed (Alimta) and cisplatin (Platinol). These medications are given intravenously (by vein) every three weeks. The most common side effects include, but are not limited to, nausea, vomiting, damage to the kidneys, numbness and tingling in the fingers or toes, decreased hearing, rash, fatigue, low white blood count that increases the risk infection, or anemia. Patients on this treatment may be given the vitamins B12 and folic acid to decrease the risk of these side effects. Other medications, such as antinausea medications, are also available to relieve many of these side effects. Peritoneal mesothelioma. As mentioned in the radiation therapy section, chemotherapy is often given directly into the abdominal cavity after surgery. Intravenous chemotherapy is also used. Just as with pleural mesothelioma, the combination of pemetrexed with cisplatin or carboplatin (Paraplat, Paraplatin) are most often used for treatment. The side effects of chemotherapy depend on the individual and the dose used, but can include fatigue, risk of infection, nausea and vomiting, loss of appetite, and diarrhea. These side effects usually go away once treatment is finished. Learn more about chemotherapy and preparing for treatment. The medications used to treat cancer are continually being evaluated. Talking with your doctor is often the best way to learn about the medications prescribed for you, their purpose, and their potential side effects or interactions with other medications. Learn more about your prescriptions by using searchable drug databases. Palliative therapy The goal of palliative therapy is to relieve the symptoms caused by cancer and cancer treatment to improve the patient’s quality of life. Examples of palliative care for mesothelioma include draining fluid that has built up in the patient’s chest or abdomen or using radiation therapy or chemotherapy to relieve symptoms. Find out more about common terms used during cancer treatment. Clinical Trials Resources
Doctors and scientists are always looking for better ways to treat patients with mesothelioma. A clinical trial is a way to test a new treatment to prove that it is safe, effective, and possibly better than a standard treatment. The clinical trial may be evaluating a new drug, a new combination of existing treatments, a new approach to radiation therapy or surgery, or a new method of treatment or prevention. Patients who participate in clinical trials are among the first to receive new treatments before they are widely available. However, there is no guarantee that the new treatment will be safe, effective, or better than a standard treatment. Patients decide to participate in clinical trials for many reasons. For some patients, a clinical trial is the best treatment option available. Because standard treatments are not perfect, patients are often willing to face the added uncertainty of a clinical trial in the hope of a better result. Other patients volunteer for clinical trials because they know that finding new drugs and other therapies is the only way to make progress in treating mesothelioma. Even if they do not benefit directly from the clinical trial, their participation may benefit future patients with mesothelioma. Sometimes people have concerns that, by participating in a clinical trial, they may receive no treatment by being given a placebo or a “sugar pill”. The use of placebos in cancer clinical trials is rare. When a placebo is used in a study, it is done with the full knowledge of the participants. Find out more about placebos in cancer clinical trials. To join a clinical trial, patients must participate in a process known as informed consent. During informed consent, the doctor should list all of the patient’s options, so the person understands how the new treatment differs from the standard treatment. The doctor must also list all of the risks of the new treatment, which may or may not be different from the risks of standard treatment. Finally, the doctor must explain what will be required of each patient in order to participate in the clinical trial, including the number of doctor visits, tests, and the schedule of treatment. Learn more about clinical trials, including patient safety, phases of a clinical trial, deciding to participate in a clinical trial, questions to ask the research team, and links to find cancer clinical trials. For specific topics being studied for mesothelioma, learn more in the Current Research section. Side Effects
Cancer and its treatment can cause a variety of side effects. However, doctors have made major strides in recent years in reducing pain, nausea and vomiting, and other physical side effects of cancer treatments. Many treatments used today are less intensive but as effective as treatments used in the past. Doctors also have many ways to provide relief to patients when such side effects do occur. Fear of treatment side effects is common after a diagnosis of cancer, but it may be helpful to know that preventing and controlling side effects is a major focus of your health care team. Before treatment begins, talk with your doctor about possible side effects of the specific treatments you will be receiving. The specific side effects that can occur depend on a variety of factors, including the type of cancer, its location, the individual treatment plan (including the length and dosage of treatment), and the person’s overall health. Ask your doctor which side effects are most likely to happen (and which are not), when side effects are likely to occur, and how they will be addressed by the health-care team if they do happen. Also, be sure to communicate with the doctor about side effects you experience during and after treatment. Learn more about the most common side effects of cancer and different treatments, along with ways to prevent or control them. In addition to physical side effects, you may experience psychosocial (emotional and social) effects as well. Learn more about the importance of addressing such needs, including concerns about managing the cost of your medical care. Learn more about late effects or long-term side effects by reading the After Treatment section or talking with your doctor. After Treatment
After treatment for mesothelioma ends, talk with your doctor about developing a follow-up care plan. This plan may include regular physical examinations and/or medical tests to monitor your recovery for the coming months and years. People treated for mesothelioma are encouraged to follow established guidelines for good health, such as maintaining a healthy weight, not smoking, eating a balanced diet, and having recommended cancer screening tests. Talk with your doctor to develop a plan that is best for your needs. Moderate physical activity can help rebuild your strength and energy level. Your doctor can help you create an appropriate exercise plan based upon your needs, physical abilities, and fitness level. Learn more about healthy living after cancer. Find out more about common terms used after cancer treatment is complete. Current Research
Research for mesothelioma is ongoing. The following advances may still be under investigation in clinical trials and may not be approved or available at this time. Always discuss all diagnostic and treatment options with your doctor. Researchers are evaluating new treatments for mesothelioma, including several promising new drugs, gene therapy, and immunotherapy. Immunotherapy (also called biologic therapy) is designed to boost the body’s natural defenses to fight the cancer. It uses materials either made by the body or in a laboratory to bolster, target, or restore immune system function. Also, research projects at various universities are underway to identify genes that become mutated or changed that may cause mesothelioma and to find blood markers (a substance found in higher than normal amounts in the blood of someone with cancer) that could help detect early-stage mesothelioma. Questions to Ask the Doctor
Regular communication with your doctor is important in making informed decisions about your health care. Consider asking the following questions of your doctor:
Patient Information Resources
In addition to Cancer.Net, there are other sources of information about this type of cancer available online. Cancer.Net maintains a list of national, not-for-profit organizations that may be helpful in finding additional information, services, and support. As always, be sure to talk with your doctor about questions you may have about information you find about this disease. View organizations that offer information on this specific type of cancer. |
