Mesothelioma

Definition of Mesothelioma

One of the rarest forms of cancer is called mesothelioma, where the malignant cells appear within the chest’s sac lining (the pleura) or within the abdomen sac lining (the peritoneum). Most of these patients will have had jobs where there was asbestos around, which was once used as insulation for buildings.

The mesothelial cells are found around the cavities in the abdomen, chest and around the heart (the pericardial sac). They also surround most of the organs in the body and form the mesothelium tissue. This tissue protects the organs through the production oflubricating fluid, so the organs can move around. For example, because of the fluid, the lungs find it easier to move during the action of breathing. The tissue in the abdomen is called the peritoneum and in the chest it is the pleura. The tissue surrounding the heart is known as the pericardium.

There are three main malignant mesotheliomas:

  • Sarcomatoid: this is the rarest type with between 7% and 20% developing this
  • Mixed/biphasic: the second rarest with between 20% and 35% falling into this one
  • Epithelioid: the most common with 50% to 70% of patients suffering from it but there is the best chance of survival with this type

Three quarters of this cancer will start within the chest cavity, known as the pleural mesotheliomas. Those that start within the abdomen, the peritoneal mesotheliomas, are responsible for between 10% and 20% of cases. Those that suffer around the heart first are the rarest of all.

The Demographics

This type of cancer is rare. In fact, there are only between 2,000 and 3,000 of new cases each year within the USA, according to the American Cancer Society; although this figure is on the rise. There was a major use of asbestos between the 1940s and 1970s, which is related to this rise. Researchers in Europe expect that the disease will reach its peak in 2020 and then start to drop down as asbestos was banned from the 1980s.

A person is usually between 50 and 70 years old when they suffer from this type of cancer and men are more likely to suffer from it than women. It is not as common among the African-Amercian people as it is among Caucasian Americans.

Mesothelioma Symptoms and Causes

Exposure to asbestos is the main risk for developing this type of cancer. It was used as insulation, with extremely effective results, but has now been taken out of use due to the link to the cancer. When the asbestos fibers are inhaled, they can penetrate through the airways and into the pleural lining. These then harm the mesothelial cells directly to cause the mesothelioma, eventually. When the fibers are swallowed, they affect the cavity of the abdomen and are linked to the peritoneal mesothelioma.

This is not just linked to asbestos though, with some radiation and chemicals being linked, including zeolite.

Many of the earlier symptoms are often ifnored due to the variety and the way they mimic many other diseases and ailments. Symptoms of mesothelioma include:

  • Trouble breathing
  • Trouble swallowing
  • Lower back/side chest pain
  • Fatigue
  • Fever
  • Cough
  • Weight loss
  • Nausea and vomiting
  • Abdmoinal pain

The last three are associated with peritoneal mesothelioma.

Diagnosing Mesothelioma

If you have any chest pain, difficulty breathing or a swelling or some pain within the abdomen, you should seek your doctor. He will take an x-ray to determine if there is something else wrong. There will also be a look over your medical history and a physical examination. The following tests will be performed to help determine if this is mesothelioma:

  • Image testing: CT scans, MRI scans and x-rays are used to see the area where you are struggling with. These can also help with detemining how bad the cancer is and the size of any tumors.
  • Pleural biopsy. This can be diffcult to do since the cancer will start at the bottom of the lungs, where the diaphragm is. When the biopsy is simple, a needle is placed into the cavity of the chest so that the membrane of the pleural can be taken to analyze it. This will usually require some local anesthestic and is not that invasive. However, there may not be enough tissue for the biopsy to get a definite conclusion. There is also a possibility that the biopsy will not be taken from where the tumor actually is since it cannot be seen. When it is not possible to make a diagnosis forthis, you may need to have an open pleural biopsy. This is invasive and a surgeon will cut into your side to get into the space needed. The surgeon will be able to explore the membranes in the pleural but will require general anesthetic.
  • Thoracoscopy: this is quite a new method and will mean that doctors can look into your chest cavity to see the tumor. It is usually done at the same time as a biopsy. A small camera is inserted into the chest through a small incision – and the doctor will obtains a tissue sample with forceps at the same time. Laparoscopy is used when it the doctor is looking for a tumor in the abdomen cavity.
  • Bronchoscopy: This will check the airways and you may have a mediastinoscopy to check the chest’s lymph nodes. The doctor will use a lighted tube for this process. A needle is often used to take samples for a biopsy. These are not very effective methods to diagnose this type of cancer since it is rare that the disease will be on the lymph nodes and airways.
  • Surgery: This can be used to get a larger sample for a biopsy or even to see the whole tumor.

Even when there are successful biospies completed, it can be difficult to diagnose the cancer. It looks very similar to other cancers when placed under the microscope so other tests are required to make sure the right diagnoses is given. Antibodies can be used during these tests to help determine whether it is mesothelioma and not lung cancer. It is also possible to use an electron microscope to check the samples and get the right diagnosis.

Treating Mesothelioma

Most people with symptoms of this cancer will first see their doctor. There are various technicians to help with the diagnosis depending on the type of imaging tests used. Afterwards, other diagnosis tests will be performed by a thoracic surgeon or a pulmonologist, who is a specialist doctor. Once the tissue samples have been gained, they will be reviewed by a pathologist to make sure the diagnosis is correct.

Patients are offered different types of treatment, depending on their cancer, including radiation therapy, surgery, chemotherapy or a mixture of each of them. A thoracic surgeon, radiation and medical oncologists and an anesthesiologist will be there, with nurses who have been specially trained to administer the chemotherapy.

Clinical Staging, Treatments and Prognosis:

The treatment and the prognosis depend on a number of factors, especially the stage that they are at with their cancer. Most of the time, patients are diagnosed with pleural mesothelioma, which is the most studied and the only one that actually has a staging system. Those stages are charted on the Butchart system, which is split into four parts:

  • Stage I: This is found in the left or right pleura and sometimes involves the lung, the diaphragm or the pericadium on that side.
  • Stage II: This is when the cancer spreads along the wall of the chest and into the heart, esophgus or on both sides of the pleura. This is when the lymph nodes may be affected.
  • Stage III: The cancer is now in the diaphragm and the abdominal cavity’s lining. Other chest lymph nodes will usually be involved too.
  • Stage IV: There will be evidence of the cancer in the distant organs, tissues or the blood.

The TNM is another way to stage this type of cancer and stands for Tumor, Spead to the Lymph Nodes and Metastasis. There are major differences to this system and the Butchart one. This is more precise and detailed; however, the Butchart system remains to be the favorite when describing and staging pleural mesotheliomas.

Patients who have this cancer do have treatments available. They include chemotherapy, radiation therapy and surgery.

The most common treatment used is surgery but is only an option when the cancer is just in one place and as long as the patient is able to withstand it. The process often involves part of the lining to be removed, whether in the abdomen or the chest, and tissue that surrounds it. Some patients need to have a lung or part of the diaphragm removed due to the spread of the cancer. When this treatment is not an option, there are other measures that are less invasive to help with the symptoms. A thoracentesis can be performed where a needle is put in the chest cavity to remove any extra chest fluid. When the fluid comes back and keeps causing the symptoms, surgical and nonsurgical efforts will be done to cause the lung cavity lining to scar so that it adheres to the lung. This means that there is no space for the fluid to come back to. This is known as sclerotherapy or sclerosis. They are palliative since they will help the symptoms but not offer a cure for the cancer.

Radiation therapy is another option to kill the cancerous cells and shrink tumors through x-rays with high energy. This is often used when patients have no option of surgery when it comes to pleural mesothelioma. It can be used with surgery or when patients have problems with their breathing, have pain or trouble swallowing.

Chemotherapy kills the cancerous cells with drugs. Methotraxate, doxorubicin and cisplatin are the most common options used and are taken orally or into the vein. They can be injected straight into the abdominal or chest cavity for this type of cancer. It is often one of the main treatments and often used with surgery, depending on the cancer stage the patient is at.

There is now a study into a new treatment option for those in the earlier stages. This is intraoperative photodrynamic therapy and uses drugs so that the cancerous cells become more sensitive to laser light and die. The drugs are used before a serugery and then a special light can shine into the chest cavity to kill off the cells.

The problem is that the disease is often advanced when symptoms show and it is diagnosed. The currently survival timeline is just a year after diagnosis in most cases. 50% of patients can live two years if they opt for aggressive treatments and it is found early enough. About 20% survive for five years after diagnosis.

Alternative and Complementary Therapies:

There is currently no proof that complementary and alternative therapies will work. However, some patients may opt for this due to the poor prognosis. It is important to talk to a doctor before using any type of medication and methods. Some studies show that these alternative options have helped with comfort for patients and include massage on the painful areas, meditation for relaxation and guided imagery for the nausea.

Coping with the Treatments

It is exhausting and difficult for many dealing with cancer. It is often worth having someone, whether a friend or family member, to help with the responsibilities around the house, offer psychological support and help with transportation. There is no need to rush back into your normal everyday activities once you receive treatment.

Clinical Trials

There are many trails and much research into mesothelioma. A lot of this is focused on how the mesothelial cells change due to asbestos to cause the cancer. Other treatments and combinations of others are also being tested, including gene therapy. Immunotherapry and other chemotherapy drugs are being tested in many clinical trials, including inter-leukins, which are hormonelike substances, and interferons to kick-start the immune system.

Preventing Mesothelioma

Limiting or even, preferably, avoid asbestos is the best way to prevent this form of cancer. Some people who are more likely to work around asbestos include construction workers, factory workers, ship builders, insulation manufacturers and miners.