Pleural Mesothelioma Causes
Pleural Mesothelioma is one of several types of cancer that affects thin tissues that line certain internal organs. Three main types of Mesothelioma have been categorized and named, according to the organ or area of the body where this cancer occurs. Mesothelioma cancer occurs primarily in the linings of the lungs, the abdominal cavity, and the heart. It is estimated that roughly 70% of all types of Mesothelioma cancers are Pleural, occurring in the lining of the lungs.
The lungs are easily a target of diseases caused by inhalation of certain substances. The mesothelial membrane is a thin lining of tissue that surrounds the chest cavity and lungs. It also is where a deadly form cancer, Pleural Mesothelioma, occurs. When toxic substances are inhaled, they can infect the lungs and any cancerous cells can then migrate into these thin tissues around the lungs. As the most common form of malignant Mesothelioma, more research also had been done on this disease form.
The lungs are surrounded by a double layer of tissues, the pleura, which also have a thin liquid in between that allows some movement without friction between the layers. The inner visceral layer is tightly wrapped around the lungs and cannot peel away. The outer parietal layer lines the interior of the chest wall, but also is very close to the visceral layer. The space between the two layers is the pleural cavity.
Causes & Risk Factors
The general cause of Pleural Mesothelioma is inhaling or ingesting of asbestos fibers that are carried into the lungs, where they cause inflammation and the genetic changes to create cancer cells. The cancer cells spread around the lungs and chest cavity. In some rare cases, this type of cancer also has developed in persons with no exposure to asbestos fibers.
Asbestos is a naturally occurring mineral group that is made up of tiny particles or fibers. In addition to asbestos, other similar minerals can create this type of cancer, including amosite, chrysotile, tremolite, crocidolite, anthophyllite, and actinolite. During handling of this element, bits of those tiny fibers can be broken off and released into the air, where they then can be inhaled or ingested.
Cancer is the result of a process where genetic mutations occur that cause a cell to grow, multiplying out of control. There are different factors, including inherited conditions, environmental elements, health and lifestyle choices that may influence the initiation and growth of cancerous cells. With Pleural Mesothelioma, it has been established that a primary cause of this cancer is exposure to asbestos minerals and having those fibers enter bodily organs like the lungs.
People at risk of this happening include anyone who mines or works with asbestos minerals, persons who come into contact with it during building construction or remodeling, and people who are exposed to it during their course of work or living environment. It also has been found that when people are exposed to this mineral, small fibers of it may also be transmitted on their clothing or hair to then infect others they are near.
Although direct exposure to asbestos fibers definitely can increase risk of developing this disease, mere exposure to asbestos does not necessarily mean that a person will develop Mesothelioma. Many people have survived years of such exposure without ever developing this type of cancer. But other people have developed Mesothelioma with only brief exposure. There are a number of other factors that might be involved with someone contracting Mesothelioma or not. For example, a family history of Mesothelioma may be a factor in other family members developing the disease. The specific causes are not definite, but it has been proven that exposure to asbestos fibers is one element that can lead to development of this type of cancer.
Symptoms & Complications
Like other forms of Mesothelioma, Pleural Mesothelioma takes decades before symptoms are revealed. This is another factor that makes this cancer so deadly. It also is quite rare, with about 3000 persons diagnosed each year at this time. It is expected that this number will increase, in part due to the lengthy development time, often as much as 30 to 50 years after exposure to asbestos. Those who were exposed to asbestos minerals during the time of heaviest use of those products during the mid-20th Century are only recently being diagnosed.
General symptoms of Pleural Mesothelioma include shortness of breath, chest pain under the rib cage, painful coughing, tissue lumps under the chest area skin and unexplained weight loss. As this cancer spreads around the chest area, it may also put additional pressure on other structures to create complications, such as pain due to pressure on nerves and spinal cord, difficulty swallowing, or development of an accumulation of chest fluid that compresses the lung and thereby makes breathing more difficult.
There are several standard treatments for Pleural Mesothelioma, and new ones are being developed through clinical trials. Surgery to remove cancer offers the best chance of eliminating the disease, but there still may be a recurrence. Participation in clinical trials offers patients an opportunity to gain the advantage of a new successful treatment before it is available to the general public.
Typical treatment includes surgery, chemotherapy and radiation. In early stages, aggressive treatment like removal of the lung is possible. When surgery is used, it may also be accompanied by chemotherapy or radiation treatments. Some options available in clinical trials include biologic and targeted therapies.
The prognosis for survival with Pleural Mesothelioma is poor, in part due to the long time it takes for this disease to become diagnosed after exposure to asbestos materials. Survival rates are based on recent cases, which also are affected by the advanced age of patients. Those who are over age 65 have the lowest rates, but many patients do have longer survival rates than the norm. It is estimated that a 5-year survival rate applies only to 5% to 10% of persons afflicted with this disease. Median survival rates vary from 12 to 21 months, depending on the stage of progression of this cancer. Aggressive treatment and surgical removal of cancer will offer the best chance of increasing survival rates.