Pleural mesothelioma is a rare malignant tumor of the pleura. In most cases, the cause can be assumed to be long-term contact with asbestos dusts. The disease is not curable and can only be treated palliatively.
What is pleural mesothelioma?
Pleural mesothelioma represents a malignant tumor of the pleura, or pleura of the chest. It is a cancer with a very poor prognosis. Often, the tumor is detected late because the preceding processes develop very slowly. After diagnosis, however, the average life span is only 18 months. Of course, there are extreme deviations in individual cases. However, a cure is usually not possible because the diagnosis is usually made only when almost the entire pleura is affected. After exposure to asbestos, pleural mesothelioma can develop after about 20 to 50 years. In the past, this cancer was very rare. However, its frequency is increasing and, according to scientists’ estimates, will culminate in the thirties of this century. This is because it is only then that the after-effects of decades of exposure to asbestos dusts come to bear. Affected are mainly people who had to deal with asbestos at work. The pleura represents the outer skin of the lungs, covering them completely and lining the chest cavity at the same time. It consists of a layer of squamous epithelium, which is separated by the pleural space from a layer of connective tissue. Both layers can be affected by the tumor. Tumors of the squamous epithelium are referred to as epithelioid mesothelioma and tumors of the connective tissue layer are referred to as sarcomadoid mesothelioma. The mixed type of both mesotheliomas is called biphasic mesothelioma. By far the most common is epithelioid mesothelioma. Sarcomadoid mesothelioma is the rarest.
Causes
The main cause of pleural mesothelioma is long-term occupational exposure of affected individuals to asbestos dusts. Today’s occupational safety measures largely prevent inhalation of asbestos or other mineral fiber dusts. In the past, however, the hazardous nature of these substances was not known. Asbestos or other mineral fibers consist of long-chain silicate fibers. When these fibers are inhaled, they become lodged in the lungs and pleura but cannot be broken down. In an attempt to get rid of the fibers, the immune system generates inflammatory reactions in the affected areas, which are always associated with tissue death. Since the asbestos fibers do not dissolve, the inflammations become chronic. However, the tissue cells of the pleura or lung that have died must be constantly replaced. After a long time, the permanent formation of new tissue can also give rise to degenerate cells that have lost their control over cell division. Cancer develops.
Symptoms, complaints, and signs
In full-blown pleural mesothelioma, the entire pleura is affected by cancer. The process of cancer formation and growth usually takes a long time. It starts already at the first exposure to asbestos fibers with the chronic inflammatory reactions. However, at the beginning there are no symptoms yet. In the run-up to tumor development, tissue changes can occur in the context of so-called asbestosis or pneumoconiosis, which can lead to respiratory problems. However, pleural mesothelioma can also develop without prior asbestosis. Thus, the first symptoms often appear at a very late stage, when almost the entire pleura is already affected. Typical symptoms are shortness of breath, chronic coughing, severe weight loss, fatigue and severe pain in the chest area. So-called pleural effusions frequently occur. These are caused by fluid formation as part of inflammatory processes in the pleura. The breathing difficulties and pain are caused on the one hand by these fluid accumulations and on the other hand by the hardening of the pleura as a result of cancer growth. The lung can no longer expand properly. Metastases form relatively late. The disease always leads to death if left untreated. It is usually not curable even by therapy. But survival time can be increased somewhat.
Diagnosis and course of the disease
Usually, pleural mesothelioma is diagnosed at an advanced stage. Imaging tests such as CT, MRI, or X-ray examinations are performed.For differential diagnosis against bronchial carcinoma, bronchoscopy with sampling is performed. Pleural puncture may allow detection of tumor cells in some cases, although lack of detection does not exclude pleural mesothelioma. The most definitive way to confirm the diagnosis is by thoracoscopy.
Complications
Unfortunately, pleural mesothelioma cannot be treated or completely recovered from. Because of the tumor, the life expectancy of the affected person is drastically reduced. However, the further course of the disease depends very much on the extent and exact location of this tumor, so it is not possible to make a general prediction. Patients with this disease primarily suffer from severe breathing difficulties. This results in gasping for breath and an undersupply of oxygen to the body. Permanent fatigue and exhaustion can also occur as a result of pleural mesothelioma and significantly reduce the quality of life of the affected person. In most cases, sufferers also experience chest pain and severe weight loss. Metastases can also form in the process and continue to lead to cancer in other regions of the body. Usually, premature death of the affected person occurs due to pleural mesothelioma. Pleural mesothelioma can no longer be treated. Various therapies can be used to alleviate the symptoms and prolong the patient’s life expectancy. However, these are always palliative measures. Special complications usually do not occur.
When should one go to the doctor?
With pleural mesothelioma, a visit to a doctor is necessary in any case. There is no self-healing with this disease, and in most cases, the symptoms will worsen if treatment is not initiated. The earlier the treatment starts, the higher the probability of a positive course of the disease. The doctor should be consulted when the pleural mesothelioma causes discomfort in the area of the lungs. The affected person suffers from a severe cough and, in general, respiratory symptoms. There is also fatigue and a severe loss of weight, which occurs for no particular reason. If pleural mesothelioma continues to be untreated, metastases will form and the affected person will continue to die. Life expectancy is significantly reduced and limited by this disease. Furthermore, chest pain can also indicate pleural mesothelioma and should be examined by a physician if it does not disappear on its own and occurs over a long period of time. Usually, pleural mesothelioma can be diagnosed by an internist. However, further treatment requires surgery and is therefore performed in a hospital.
Treatment and therapy
Similar to other malignant tumors, the three treatment methods of surgery, radiation, and chemotherapy are combined for pleural mesothelioma. In this context, there is no universally accepted recommendation for the implementation of therapy. Treatment depends on physical fitness and disease stage. In the case of unilateral pleural mesothelioma, removal of one half of the lung, including the pleura, can help prolong life. The surgical method is then combined with chemotherapy and radiation. Chemotherapy involves administering the cytostatic drug permetrexed along with a platinum-containing drug. It has also been shown that the additional administration of the vascular growth inhibitory monoclonal antibody bevacizumab improves survival. In most cases, however, this is only a few months. In rare cases, however, life expectancy has been extended by several years. The therapies are palliative measures. A cure cannot be assumed.
Prevention
Pleural mesothelioma can be effectively prevented only by preventing exposure to asbestos or mineral fibers. Pre-exposed individuals should also be sure to avoid smoking, as it further increases the risk of developing pleural mesothelioma.
Follow-up
In most cases, those affected by pleural mesothelioma have very few or only very limited measures of direct aftercare available to them.Affected persons are primarily dependent on a quick and early diagnosis to prevent further complications or further discomfort. If the tumor has already spread in the body, this disease can sometimes no longer be completely cured. In this case, the patient’s life expectancy may be significantly reduced due to pleural mesothelioma. Sufferers usually rely on chemotherapy to remove the tumor. In the process, most sufferers also need the support and also care of their own family and friends. Among other things, loving and intensive conversations have a very positive effect on the further course of the disease and can also prevent depression or other psychological upsets. Even after a successful therapy, regular checks by a doctor are very important in order to detect other tumors at an early stage. However, the further course depends very much on the time of diagnosis, so that a general prediction cannot be made.
What you can do yourself
Due to the generally quite late diagnosis of pleural mesothelioma, the patient himself can usually contribute little to the cure. The focus for him is therefore on improving his own quality of life or well-being. On the one hand, the patient is advised to avoid additional stress on the diseased lung. This includes smoking, staying in inner-city areas that are polluted with particulate matter, and intensive sporting activities. On the other hand, it makes sense to take trips to regions with very good air quality, if this is still possible. These can also reduce unnecessary stress, which would put additional strain on the already weakened body. Furthermore, the patient is also advised to learn special breathing exercises to strengthen the lungs. On the other hand, it is also advisable to seek psychological support. A tumor disease is a serious life event that is demonstrably easier for the patient to cope with if he or she receives qualified therapy or attends a self-help group. Possible prejudices or even shame should be put aside in view of the seriousness of the disease. With regard to nutrition, attention should also be paid to well-being. Anything that tastes good can be eaten. Due to the mostly existing loss of appetite, only a sufficient calorie and nutrient intake is important.
