The body of knowledge available for the general public about Mesothelioma can be daunting both in scope and complexity. So it is felt that a summarized mesothelioma information should be made available in this directory. In this page, you will find information relating to the origin of this disease to its prognosis,various treatment options available and links to further mesothelioma information.
Is a rare form of lung cancer, possibly associated with exposure to asbestos. The National Cancer Institute defines mesothelioma as "a rare form of cancer, a disease in which cancer (malignant) cells are found in the sac lining the chest (the pleura), the lining of the abdominal cavity (the peritoneum) or the lining around the heart (the pericardium)".
Mesothelioma - etiology:
Many people who have breathed asbestos or people who have lived in environment close to asbestos material are diagnosed with mesothelioma after a latency period of several years. However, not everyone who is exposed to asbestos develops mesothelioma. It is not that the asbestos by itself triggers mesothelioma - but the fibers of asbestos - which are released from asbestos material when they are worked, damaged or disturbed in any way may eventually result in this dreadful disease - mesothelioma. These asbestos fibers are highly carcinogenic when inhaled or ingested as they stay indefinitely in our body tissues.
Refers to a group of naturally occurring minerals which are resistant to heat, fire, most chemicals and significantly for us - suffer no biological degradation. Asbestos is composed of silicon, oxygen, hydrogen and some other metals.
Because of its unique properties, asbestos is widely used in a variety of industries and even in homes. Asbestos cement sheets and pipe products are used for water supply and sewage piping, roofing and siding, casings for electrical wires, support sheets in furnaces, fire protection material, electrical switchboards / components and residential / industrial building materials. In the late 1970s, the U.S. Consumer Product Safety Commission banned the use of asbestos in wallboard patching compounds and gas fireplaces because these products released excessive amounts of asbestos fibers into the environment. Asbestos is still widely used in friction products - brake linings and gaskets.
The most common asbestos - Chrysotile, white in color belongs to the serpentine family of mineral group. It is flexible and curved whilst its more dangerous cousin - amphibole asbestos has rod or needle-like shape in addition to being brittle. This makes amphibole asbestos - the most dangerous. They come in odd colors too - Amosite is brown or grey in color as it contains iron and magnesium whilst Crocidolite is blue as it contains sodium iron magnesium silicate. Tremolite consists of calcium, magnesium and iron silicate - white to grayish green in color. Chrysotile is the only type of asbestos mined on a large scale throughout the world. But some quantities of Tremolite asbestos are still mined in India and sadly in some of the third world countries amphibole asbestos is still being widely used as roofing material and constructional material in many homes. This raises the spectre of increased incidence of mesothelioma in these countries in future.
The onset of mesothelioma is often insidious. The early symptoms are non-specific and in some cases resemble viral pneumonia that may lead to a delay in diagnosis. Pleural mesothelioma is a type of mesothelioma occurring at the pleura - the lining around the outside of the lungs. Some pleural mesothelioma patients may complain shortness of breath, chest pain and/or persistent cough whilst others may exhibit no significant symptoms at all. A chest x-ray may show a build-up of fluid or pleural effusion - an accumulation of fluid between the lining of the lung and the chest cavity. Most of the time - about 60% of the cases, the right lung is affected. Less common symptoms of pleural mesothelioma include fever, night sweats and weight loss. Symptoms of peritoneal mesothelioma may include pain or swelling in the abdomen (due to a build-up of fluid), nausea, weight loss, bowel obstruction, anemia or swelling of the feet. In Pleural Effusions, as the volume of accumulated fluid increases, shortness of breath - dyspnea, in medical parlance, accompanied by pain results in some cases.
Be aware of the fact that all the forgoing symptoms may also be caused by less serious ailments. Only a physician can make a definitive diagnosis. Xrays and CT scans may help in identifying effusions whilst a diagnostic thoracentesis, in which cells are extracted from the pleural cavity, is many times used as an aid in the diagnosis of mesothelioma.
Definitive diagnosis often calls for pathological examination or a biopsy, where a small part of the the abnormal tissue is excised and subjected to microscopic examination. For pleural mesothelioma the doctor would use a special instrument called a thoracoscope to view the inside of the chest cavity - under local anesthesia. Accumulated fluid can be drained by a suction process called as thoracentesis. In the case of peritoneal mesothelioma, the surgeon may use peritoneoscope to peer into the opening made in the abdomen - under local anesthesia. The accumulated fluid will be drained by similar suction process known as paracentesis. If after a thorough review by a pathologist, the physician may order PET (Positron Emission Tomography) which shows a three-dimensional image of areas of increased metabolism (cancers), as hot spots. This clear picture may help form a treatment plan for mesothelioma after careful review.
Treatment of mesothelioma depends on so many factors and oncologists - including: the stage of the cancer, where the cancer is and how far the cancer has spread - to the age and general condition of the patient. Many doomsday prediction - of the expected survival rate of 8 to 12 months, has been belied by some of the specialists in treating mesothelioma. Traditionally there are three kinds of treatment for mesothelioma:
Surgery: Pleurectomy - decortication is the surgical removal of part of the chest or abdominal lining and some of the tissue around it. Pleurectomy is most often considered a palliative procedure to relieve chest wall pain and to prevent recurring pleural effusions. While extensive debulking of the tumor is possible, resection is often incomplete along the diaphragmatic and mediastinal pleura. In some cases, pneumonectomy - surgical removal of a lung may be resorted to depending upon the extent of the spread of the malignant cancer. In extreme cases, extrapleural pneumonectomy is performed in which the diaphragm and the lining around the heart may also be excised.
Chemotherapy: Chemotherapy drugs are divided into several categories based on how they affect specific chemical substances within cancer cells and their interaction. They may be used to shrink a tumor before surgery (neo-adjuvant therapy), to help destroy cancer cells that may remain after surgery (adjuvant chemotherapy) or to make radiation therapy or immunotherapy work more effectively against mesothelioma. In addition to standby drugs such as cisplatin, gemcitabine, alimta, and anti-angiogenesis agents such as bevacizumab and endostatin are being vigorously pursued by researchers who have made significant progress in this direction.
Radiation therapy: High energy Xray radiation is used to shrink or kill malignant cancerous cells. The source of radiation can be from the outside (external radiation therapy) or through radioisotopes which results in internal radiation.