Mesothelioma is a relatively rare form of cancer linked to chronic asbestos exposure. There has been a sharp decline in asbestos exposure since the 1970s when asbestos use was halted for most applications. However, the incubation period for mesothelioma from initial exposure to asbestos to the onset of the disease varies from 20 to 50 years. As such, deaths related to this disease have risen recently and are expected to continue rising until the year 2020. This anticipated increase in incidence of mesothelioma has spurred considerable interest in clinical trials to develop better treatments for the deadly disease.
Mesothelioma Clinical Trials
Until recently, clinical trials for mesothelioma were difficult to conduct. The disease had a rapid onset and progression, leading to a relatively short survival period in which to conduct clinical trials. Also, there was a lack of basic understanding about the clinical biology of the disease and how the disease changed during progression.
Specific clinical measures were difficult to obtain in order to demonstrate the response to treatment. Recently, as part of the Alimta clinical trial, researchers developed new metrics that included factors other than just pleural thickening or abnormal breathing capability. A number of new clinical trials are now underway, many of them using these new measurement techniques. Hopefully these trials will lead to ways to stop or reverse the progression of mesothelioma.
Mesothelioma Trial Phases
Clinical trials for evaluating mesothelioma treatments are broken into four parts or phases. These Phases are described below (Source FDA).
Phase I
Researchers evaluate a drug or treatment in a small group of people/patients (20 to 80) for the first time to evaluate a drug's safety, determine the appropriate dosage range and identify side effects.
Phase II
Researchers treat a larger group of people/patients to determine if the drug treatment is effective and safe for the dosage levels determined in Phase I.
Phase III
Researchers administer the drug or treatment to a large group of people/patients to confirm the effectiveness of the drug and evaluate the drug's side effects. In this phase, the drug under evaluation will be compared to commonly used treatments. Additionally, researchers use Phase III trials to determine the proper protocol for the use of the drug when it is released for routine treatment.
Phase IV
Researchers perform follow-up studies from Phase III, primarily to obtain information that can be used when marketing the drug, such as drug risks, benefits and optimum use.
Thursday, August 20, 2009
Mesothelioma Symptoms
Mesothelioma symptoms are not specific to the disease; that is, many mesothelioma symptoms are also symptoms of other medical problems. Most studies show that the symptoms of mesothelioma usually begin to appear 30 to 40 years after exposure to asbestos. Thus, many mesothelioma patients are unaware that the symptoms they are experiencing are related to something that happened much earlier in their lives. Even a short period of asbestos exposure (as little as a few months) can create the conditions for a disease that erupts much later in life.
Mesothelioma affects the lining of various cavities in the body. Over time, the growth of cancerous tumors causes these tissues to expand and gather fluid. The presence of excess fluid is typically what causes the symptoms to occur. Mesothelioma symptoms also depend on the location of the tumors.
Pleural Mesothelioma Symptoms
For pleural mesothelioma, or mesothelioma of the lining surrounding the lung, common symptoms include shortness of breath, chest pain and a persistent cough. Unfortunately, these symptoms are also very common for a number of other ailments, including pneumonia. The most common symptom is localized chest pain, but this may not occur until the disease is well advanced. A less common but still prevalent symptom of pleural mesothelioma is weight loss. Some patients show virtually no symptoms.
Peritoneal Mesothelioma Symptoms
Peritoneal mesothelioma is a cancer of the abdominal lining. Symptoms include swelling or a mass in the abdomen, weight loss and abdominal pain. Bowel obstruction and blood clots also have been known to occur and fever is sometimes present.
Pericardial Mesothelioma Symptoms
Pericardial mesothelioma affects the lining of the heart, or pericardium. Symptoms include chest pain, cough, irregular heart beat and irregular breathing patterns. Many of these symptoms manifest during physical exertion – even minimal exertion. Pericardial mesothelioma is the rarest type of mesothelioma.
The earlier cancer is detected – mesothelioma or otherwise – the more effective treatment aimed at halting its progression will be.
Mesothelioma affects the lining of various cavities in the body. Over time, the growth of cancerous tumors causes these tissues to expand and gather fluid. The presence of excess fluid is typically what causes the symptoms to occur. Mesothelioma symptoms also depend on the location of the tumors.
Pleural Mesothelioma Symptoms
For pleural mesothelioma, or mesothelioma of the lining surrounding the lung, common symptoms include shortness of breath, chest pain and a persistent cough. Unfortunately, these symptoms are also very common for a number of other ailments, including pneumonia. The most common symptom is localized chest pain, but this may not occur until the disease is well advanced. A less common but still prevalent symptom of pleural mesothelioma is weight loss. Some patients show virtually no symptoms.
Peritoneal Mesothelioma Symptoms
Peritoneal mesothelioma is a cancer of the abdominal lining. Symptoms include swelling or a mass in the abdomen, weight loss and abdominal pain. Bowel obstruction and blood clots also have been known to occur and fever is sometimes present.
Pericardial Mesothelioma Symptoms
Pericardial mesothelioma affects the lining of the heart, or pericardium. Symptoms include chest pain, cough, irregular heart beat and irregular breathing patterns. Many of these symptoms manifest during physical exertion – even minimal exertion. Pericardial mesothelioma is the rarest type of mesothelioma.
The earlier cancer is detected – mesothelioma or otherwise – the more effective treatment aimed at halting its progression will be.
Wednesday, August 19, 2009
Pleural Mesothelioma: Mesothelioma of the Pleura
Pleural mesothelioma is a disease that affects the lining of the lungs, or lung pleura. Sometimes doctors refer to this disease as mesothelioma of the pleura. It is a common misconception that mesothelioma is a type of primary lung cancer; it is not. Mesothelioma is a cancer of the serous membranes. These membranes enclose a number of organs throughout the midsection of the body, including the lungs. The most common type of mesothelioma, pleural mesothelioma, affects the serous membranes of the lungs.
Mesothelioma can also affect the serous membranes surrounding the abdomen, called peritoneal mesothelioma, and the membranes surrounding the heart, or pericardial mesothelioma. When mesothelioma spreads to the lungs from the serous linings of the lungs, abdomen or heart, it is considered secondary lung cancer. Also, pleural mesothelioma is sometimes referred to as an asbestos lung cancer. Technically, cancers that do not originate in the lungs are not considered lung cancer; thus, terms such as secondary lung cancer and asbestos lung cancer (pleural mesothelioma) are misleading. Asbestosis is a type of asbestos lung disease that does originate in the lungs and is often confused with mesothelioma.
Pleural Mesothelioma Cancer
Pleural mesothelioma cancer represents about 75 percent of all mesothelioma cases. This disease is caused by the inhalation of asbestos fibers, which then settle in the lungs. These asbestos fibers become imbedded in the lining of the lung (the pleura). Over time, they cause chronic inflammation that eventually leads to growth of cancerous tumors or, in some cases, asbestosis.
Pleural mesothelioma cancer normally appears as multiple tumor masses affecting the parietal surface (outside; further from the lung) and visceral surface (inside; closer to the lung) of the pleura. Typically, the parietal surface has greater involvement than the visceral. There is a slightly higher incidence of mesothelioma in the right lung, apparently due to the fact that the right lung is larger and has a greater amount of pleural surface area. Also, the lower lungs typically show more tumor masses than the upper lung. This is thought to be due to gravitational factors influencing how the asbestos fibers settle in the lungs after they have been inhaled.
Large growths in the pleura are normally noted in patients upon diagnosis. As the diseases progresses, these growths lead to a complete obliteration of the lung cavity. The tumors can spread from the lung pleura to other organs, including the heart and abdomen. Mesothelioma can also invade the lymph nodes and circulatory system.
Tumors unrelated to pleural mesothelioma also grow in the pleura. These tumors start in other parts of the body and metastasize to the pleura. The most common form of non-pleural mesothelioma cancer that occurs is lung cancer, representing about 36 percent of the cancer occurring in the pleura. The next most common forms are breast cancer (25 percent), ovarian cancer (5 percent) and gastric cancer (2 percent). Lymphoma also accounts for a small portion of cancers that metastasize to the pleura.
Pleural Mesothelioma Symptoms
The most common symptom for pleural mesothelioma patients is chest pain. But, the pain often is not associated directly with the lung pleura and often appears in the shoulder or upper abdomen. Shortness of breath, called dyspnea, is also a symptom. Cough, weight loss and anorexia are present in some patients, but are less common. Finally, the rapid growth of the pleural mesothelioma cancer tumors enlarges the pleural space, causing it to fill with fluid, which leads to the discomfort or pain associated with first detection of the disease.
Pleural mesothelioma patients display all three types of mesothelioma cancer cells: epithelioid mesothelioma, sarcomatoid mesothelioma and biphasic mesothelioma.
Pleural Mesothelioma Prognosis
In a study involving 167 patients with proven pleural mesothelioma, the median survival rate of patients following diagnosis was 242 days. The survival rate was also affected by the type of mesothelioma cancer cells; patients with biphasic cell types have the shortest life expectancy.
Mesothelioma can also affect the serous membranes surrounding the abdomen, called peritoneal mesothelioma, and the membranes surrounding the heart, or pericardial mesothelioma. When mesothelioma spreads to the lungs from the serous linings of the lungs, abdomen or heart, it is considered secondary lung cancer. Also, pleural mesothelioma is sometimes referred to as an asbestos lung cancer. Technically, cancers that do not originate in the lungs are not considered lung cancer; thus, terms such as secondary lung cancer and asbestos lung cancer (pleural mesothelioma) are misleading. Asbestosis is a type of asbestos lung disease that does originate in the lungs and is often confused with mesothelioma.
Pleural Mesothelioma Cancer
Pleural mesothelioma cancer represents about 75 percent of all mesothelioma cases. This disease is caused by the inhalation of asbestos fibers, which then settle in the lungs. These asbestos fibers become imbedded in the lining of the lung (the pleura). Over time, they cause chronic inflammation that eventually leads to growth of cancerous tumors or, in some cases, asbestosis.
Pleural mesothelioma cancer normally appears as multiple tumor masses affecting the parietal surface (outside; further from the lung) and visceral surface (inside; closer to the lung) of the pleura. Typically, the parietal surface has greater involvement than the visceral. There is a slightly higher incidence of mesothelioma in the right lung, apparently due to the fact that the right lung is larger and has a greater amount of pleural surface area. Also, the lower lungs typically show more tumor masses than the upper lung. This is thought to be due to gravitational factors influencing how the asbestos fibers settle in the lungs after they have been inhaled.
Large growths in the pleura are normally noted in patients upon diagnosis. As the diseases progresses, these growths lead to a complete obliteration of the lung cavity. The tumors can spread from the lung pleura to other organs, including the heart and abdomen. Mesothelioma can also invade the lymph nodes and circulatory system.
Tumors unrelated to pleural mesothelioma also grow in the pleura. These tumors start in other parts of the body and metastasize to the pleura. The most common form of non-pleural mesothelioma cancer that occurs is lung cancer, representing about 36 percent of the cancer occurring in the pleura. The next most common forms are breast cancer (25 percent), ovarian cancer (5 percent) and gastric cancer (2 percent). Lymphoma also accounts for a small portion of cancers that metastasize to the pleura.
Pleural Mesothelioma Symptoms
The most common symptom for pleural mesothelioma patients is chest pain. But, the pain often is not associated directly with the lung pleura and often appears in the shoulder or upper abdomen. Shortness of breath, called dyspnea, is also a symptom. Cough, weight loss and anorexia are present in some patients, but are less common. Finally, the rapid growth of the pleural mesothelioma cancer tumors enlarges the pleural space, causing it to fill with fluid, which leads to the discomfort or pain associated with first detection of the disease.
Pleural mesothelioma patients display all three types of mesothelioma cancer cells: epithelioid mesothelioma, sarcomatoid mesothelioma and biphasic mesothelioma.
Pleural Mesothelioma Prognosis
In a study involving 167 patients with proven pleural mesothelioma, the median survival rate of patients following diagnosis was 242 days. The survival rate was also affected by the type of mesothelioma cancer cells; patients with biphasic cell types have the shortest life expectancy.
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