Mesothelioma
Introduction
Malignant mesothelioma is a rare cancer that occurs in the thin layer of tissue that covers the majority of your internal organs (mesothelium). Doctors divide mesothelioma into different categories based on what part of the mesothelium is affected by cancer. Mesothelioma that occurs in the tissue that surrounds the lung (pleura) is called pleural mesothelioma and is the most common form. Mesothelioma that occurs in the tissue in your abdomen (peritoneum) is called peritoneal mesothelioma and accounts for 10 percent to 20 percent of all mesotheliomas. In rare cases, mesothelioma can also occur in the lining around the heart (pericardium) and in the lining around the testicles (tunica vaginalis).
Between 2,000 and 3,000 people are diagnosed with mesothelioma in the United States each year. Men are more likely to develop mesothelioma than are women. It's more common in older adults — most people with mesothelioma are 65 and older — though mesothelioma can be diagnosed at any age.
Mesothelioma is closely linked to exposure to asbestos — a natural fiber that was once used in manufacturing a wide variety of industrial and household products. Mesothelioma rates have increased during the past 20 years in response to the widespread use of asbestos in the past. Many industrialized countries now limit asbestos use and enforce laws to protect workers who may be exposed. Researchers predict these efforts will lead to fewer cases of mesothelioma in the future.
Signs and symptoms
Signs and symptoms of mesothelioma vary depending on where the cancer occurs.
Pleural mesothelioma signs and symptoms may include:
- Shortness of breath
- Painful breathing
- Chest pain under the rib cage
- Unusual lumps of tissue under the skin on your chest
- Unexplained weight loss
- Dry (nonproductive) cough
- Abdominal pain
- Abdominal swelling
- A change in your bowel habits, such as more frequent diarrhea or constipation
- Lumps of tissue in the abdomen
- Unexplained weight loss
Signs and symptoms of mesothelioma that has spread to other parts of the body include:
- Pain in the area where cancer has spread
- Difficulty swallowing
- Swelling in the neck and face
Causes
In general, cancer begins with a genetic mutation that turns normal, healthy cells into abnormal cells. Healthy cells grow and multiply at a set rate, eventually dying at a set time. Abnormal cells grow and multiply out of control, and they don't die. The accumulating abnormal cells form a mass (tumor). Cancer cells invade nearby tissues and can break off from an initial tumor to spread elsewhere in the body (metastasize).
It isn't clear what causes the initial genetic mutation that leads to mesothelioma, though researchers have identified factors that may increase the risk. It's likely that cancers form because of an interaction between many factors, such as inherited conditions, your environment, your health conditions and your lifestyle choices.
Treatment
What treatment you undergo for mesothelioma depends on your health and certain aspects of your cancer, such as its stage and location. Unfortunately, mesothelioma often is an aggressive disease and for many people a cure won't be possible. Mesothelioma is usually diagnosed at an advanced stage — when it isn't possible to remove the cancer through surgery. Instead, your doctor may work to control your cancer and its signs and symptoms to make you more comfortable.
Discuss your treatment goals with your doctor. Some people want to do everything they can to treat their cancer, even if that means enduring side effects for a small chance of a cure. Others prefer treatments that make them comfortable so that they can live their remaining months as symptom-free as possible.
Mesothelioma treatment options may include surgery, radiation, chemotherapy and clinical trials.
Surgery
Surgeons work to remove mesothelioma from your body. Sometimes it isn't possible to remove all of the cancer. In those cases, surgery may help to reduce the signs and symptoms caused by mesothelioma spreading in your body. Surgical options may include:
- Surgery to decrease fluid buildup. Pleural mesothelioma may cause fluid to build up in your chest, causing difficulty breathing. Surgeons insert a tube or catheter into your chest to drain the fluid. Surgeons may also inject medicine into your chest to prevent fluid from returning (pleurodesis).
- Surgery to remove the tissue around the lung or abdomen. Surgeons may use scalpels and other surgical tools to remove the tissue lining the ribs and the lungs (pleurectomy) or the tissue lining the abdominal cavity (peritonectomy) in order to relieve signs and symptoms of mesothelioma.
- Surgery to remove as much of the cancer as possible (debulking). If all of the cancer can't be removed, surgeons may attempt to remove as much as possible.
- Surgery to remove a lung and the surrounding tissue. Removing the affected lung and the tissue that surrounds it may relieve signs and symptoms of pleural mesothelioma. This procedure also allows doctors to use higher doses of radiation against any remaining mesothelioma, since doctors won't need to worry about protecting your lung from damaging radiation.
Chemotherapy uses chemicals to kill cancer cells. Chemotherapy drugs travel throughout your body and kill rapidly growing cells. This works against cancer cells, but also affects other rapidly growing cells in your body, such as those in your hair follicles and those in your gastrointestinal system. Chemotherapy may slow the growth of pleural mesothelioma. Chemotherapy can be used before surgery (neoadjuvant chemotherapy) or after surgery (adjuvant chemotherapy) to reduce the signs and symptoms you may experience from mesothelioma.
People with peritoneal mesothelioma may receive adjuvant chemotherapy drugs that have been heated (hyperthermic chemotherapy). Rather than being distributed throughout the body, chemotherapy drugs are often injected directly into the abdominal cavity (intraperitoneal chemotherapy), where they can reach the peritoneal mesothelioma directly without injuring healthy cells in other parts of the body. This allows doctors to administer higher doses of chemotherapy drugs. Intraperitoneal chemotherapy may also be used to reduce the signs and symptoms of peritoneal mesothelioma that can't be removed through surgery.
Radiation therapy
Radiation therapy focuses high-energy radiation to a specific spot or spots on your body. Radiation may reduce signs and symptoms in people with pleural mesothelioma. Doctors aim radiation at the entire chest to obtain the best result. However, many sensitive organs reside in the chest, such as the heart, lungs and spinal cord, so doctors must use low doses of radiation to spare these organs. Radiation therapy is sometimes used after biopsy or surgery to prevent mesothelioma from spreading to the surgical incision.
Radiation therapy is used occasionally in people with peritoneal mesothelioma. Radiation may reduce signs and symptoms of mesothelioma.
Combination therapy
Surgery, chemotherapy and radiation therapy may be combined. This aggressive therapy can be grueling and may not be appropriate for everyone. Younger, healthier people and those with earlier stage mesothelioma may be more able to endure this treatment. Combination therapy has shown the most promise in treating mesothelioma. However, most people will eventually experience a recurrence of this cancer despite this aggressive treatment. Combination therapy has been used in both pleural mesothelioma and peritoneal mesothelioma.
Clinical trials
Clinical trials are studies of new mesothelioma treatment methods. People with mesothelioma may opt for a clinical trial for a chance to try new types of treatment. However, a cure isn't guaranteed. Carefully consider your treatment options and talk to your doctor about what clinical trials are open to you. Your participation in a clinical trial may help doctors better understand how to treat mesothelioma in the future.
Treatment for other types of mesothelioma
Pericardial mesothelioma and mesothelioma of the tunica vaginalis are very rare and can be very aggressive. Early-stage cancer may be removed through surgery. Doctors have yet to determine the best way to treat later stage cancers, though. Your doctor may recommend other treatments to improve your quality of life.
Prevention
Reducing your exposure to asbestos may reduce your risk of mesothelioma. Most people with mesothelioma were exposed to the asbestos fibers at work. Workers who may encounter asbestos fibers include:
- Miners
- Factory workers
- Insulation manufacturers
- Railroad workers
- Ship builders
- Gas mask manufacturers
- Construction workers
Older homes and buildings may contain asbestos. In many cases, it's more dangerous to remove the asbestos than it is to leave it intact. Breaking up asbestos may cause fibers to become airborne, where they can be taken into your body as you breathe. Consult experts trained to detect asbestos in your home. These experts may test the air in your home to determine whether the asbestos is a risk to your health. Don't attempt to remove asbestos from your home — hire a qualified expert.
Informations obtained from National Institute of Health.