Mesothelioma cancer is a disease in which malignant (cancer) cells are found in the pleura which is a thin layer of tissue that lines the chest cavity and covers the lungs or the peritoneum which is a thin layer of tissue that lines the abdomen and covers most of the organs in the abdomen.
Mesothelioma cancer is a rare cancer that occurs in the thin layer of tissue that covers the majority of the internal organs (mesothelium).
Mesothelioma is divided 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 the 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).
Men are more likely to develop mesothelioma than are women. It’s more common in older adults. Most people with mesothelioma cancer are 65 and older. Between 2,000 and 3,000 people are diagnosed with mesothelioma cancer in the United States each year.
Mesothelioma cancer is closely linked to exposure to asbestos. Asbestos is a natural fiber that was once used in manufacturing a wide variety of industrial and household products. Mesothelioma cancer 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 cancer in the future.
Being exposed to asbestos can affect the risk of developing malignant mesothelioma.
Many people with malignant mesothelioma cancer have worked or lived in places where they inhaled or swallowed asbestos. After being exposed to asbestos, it usually takes a long time for malignant mesothelioma cancer to occur. Other risk factors for malignant mesothelioma cancer include the following:
- Living with a person who works near asbestos.
- Being exposed to a certain virus.
Causes of Mesothelioma Cancer
Generally 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, though not required 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 are the causes of mesothelioma cancer. The initial genetic mutation that leads to mesothelioma, though researchers have identified factors that may increase the risk may be one of the cause. It’s likely that cancers form because of an interaction between many factors, such as inherited conditions, environment, person’s health conditions and lifestyle choices.
Stages of Mesothelioma
After malignant mesothelioma cancer has been diagnosed, tests are done to find out if cancer cells have spread to other parts of the body. The process used to find out if cancer has spread outside the pleura or peritoneum is called staging.
The information gathered from the staging process determines the stage of the disease. It is important to know the spread of the cancer in order to plan treatment.
The stages of mesothelioma cancer are divided into two groups.
Stages of mesothelioma cancer are grouped into localized and advanced.
- Localized malignant mesothelioma (stage I): Cancer is found in the lining of the chest wall and may also be found in the lining of the lung, the lining of the diaphragm, or the lining of the sac that covers the heart on the same side of the chest.
- Advanced malignant mesothelioma: includes stage II, stage III, and stage IV.
- In stage II, cancer is found in the lining of the chest wall and the lymph nodes on the same side of the chest. Cancer may also be found in the lining of the lung, the lining of the diaphragm, or the lining of the sac that covers the heart on the same side of the chest.
- In stage III, cancer has spread to any of the following areas:
- The chest wall.
- The mediastinum.
- The heart.
- Beyond the diaphragm.
- The peritoneum.
- Cancer may have also spread to lymph nodes on the other side of the chest or outside the chest.
- In stage IV, cancer has spread to distant organs or tissues.
Recurrent Malignant Mesothelioma
Recurrent malignant mesothelioma cancer is cancer that has recurred (come back) after it has been treated. The cancer may come back in the chest or abdomen or in other parts of the body.
Mesothelioma Symptoms or Sign of Mesothelioma Cancer
Mesothelioma symptoms or Sign of Mesothelioma Cancer vary depending on where the cancer occurs.
Pleural mesothelioma cancer signs and symptoms may include:
- Painful breathing
- Shortness of breath
- Chest pain under the rib cage
- Unusual lumps of tissue under the skin on the chest
- Dry (nonproductive) cough
- Unexplained weight loss
- A change in the bowel habits, such as more frequent diarrhea or constipation
- Abdominal swelling
- Abdominal pain
- Unexplained weight loss
- Lumps of tissue in the abdomen
Mesothelioma cancer of the tunica vaginalis may be first detected as a mass on a testicle. Pericardial mesothelioma cancer signs and symptoms may include difficulty breathing and fever. These forms are so rare that the signs and symptoms are not much clear.
Signs and symptoms of mesothelioma cancer 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
Mesothelioma treatment is of different types for patients with the disease. Different types of treatments are available for patients with malignant mesothelioma. Some mesothelioma cancer treatments are standard which are the currently used, and some are being tested in clinical trials. Before starting treatment, patients may want to think about taking part in a clinical trial.
A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment.
Clinical trials are taking place in many parts of the country. Information about ongoing clinical trials is available from the NCI Web site. Choosing the most appropriate cancer treatment is a decision that ideally involves the patient, family, and health care team.
Three types of standard treatment are used:
The following surgical treatments may be used for malignant mesothelioma:
- Wide local excision: This type of surgery is used to remove the cancer and some of the healthy tissue around it.
- Pleurectomy and decortication: This type of surgery is used to remove part of the covering of the lungs and lining of the chest and part of the outside surface of the lungs.
- Extrapleural pneumonectomy: This type of surgery is used to remove one whole lung and part of the lining of the chest, the diaphragm, and the lining of the sac around the heart.
- Pleurodesis: is a surgical procedure that uses chemicals or drugs to make a scar in the space between the layers of the pleura. Fluid is first drained from the space using a catheter or chest tube and the chemical or drug is put into the space. The scarring stops the build-up of fluid in the pleural cavity.
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. Chemotherapy uses chemicals to kill cancer cells.
When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body which is why it is called systemic chemotherapy.Thus killing rapidly growing cells.
When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). Combination chemotherapy is the use of more than one anticancer drug.
The way the chemotherapy is given depends on the type and stage of the cancer being treated. This works against cancer cells, but also affects other rapidly growing cells in the body, such as those in the hair follicles and those in the 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 one may experience from mesothelioma.
People with peritoneal mesothelioma cancer 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 cancer 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 cancer that can’t be removed through surgery.
Biologic therapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.
Mesothelioma Cancer Prognosis
Like most cancers, the prognosis for malignant mesothelioma cancer often depends on how early it is diagnosed and how aggressively it is treated. Malignant mesothelioma cancer usually is advanced by the time it is diagnosed so the outlook usually is poor.
On an average, the survival time after diagnosis is about one year. However, several factors affect the mesothelioma cancer prognosis including:
- the extent of the tumor
- the age and
- health of the patient.
In some cases, survival time can be increased to two to five years or more with early detection and aggressive treatment. Improved treatments should be available in the near future.
A mesothelioma cancer diagnosis is serious, but treatments are available for this often-fatal cancer. The chance of recovery, or prognosis, depends on the size of the cancer, where the cancer is, how far the cancer has spread, how the cancer cells look under the microscope, how the cancer responds to treatment, and the patient’s age.
As with most types of cancer, early detection is an excellent first step in fighting the disease. The potential for any treatment to be successful depends on a variety of factors including overall health and age of the patient, type of tumor, size of tumor, and location of tumor and lymph system involvement.
Mesothelioma Cancer Survival Rate
Generally speaking, with cancer the outcome depends on how advanced the cancer is when it is diagnosed. Usually with cancer, the statistics are given for each stage. Stage is just as important for mesothelioma cancer as it is for other cancers. But finding the statistics for mesothelioma cancer survival rate is more difficult to do. This is because Mesothelioma cancer is not all that common, (although incidence is increasing).
It is usually diagnosed when it is advanced as people may not have symptoms early. Even though there are two types of mesothelioma cancer the prognosis for each type is poor.
By the time someone has symptoms and goes to their doctor, the disease is very often advanced. Because few people are diagnosed early, there are no reliable statistics for 5 year early stages of mesothelioma cancer survival rate.
For both types of mesothelioma cancer, patients are often told that they may have less than a year to live.
Generally, of all those people diagnosed with mesothelioma cancer only about 1 in 10 (10%) will be alive 3 years later and 1 in 20 (5%) will be alive 5 years later. For those people who have been diagnosed and treated in the earlier stages of the disease, there is little information to draw on.
But we have seen reports that quote survival rates of up to 1 in 2 (50%) after 2 years. So the range of survival times is very wide. Survival depends on other factors, as well as stage.