Pleural Mesothelioma

Cancer that affects the mesothelium, a lining that surrounds many areas of the body, including the pulmonary and cardiac organs, is known as mesothelioma. Mesothelioma occurs when the cells in the mesothelium divide uncontrollably.

Types of Mesothelioma

Pleural mesothelioma develops in the pulmonary (lungs) area, peritoneal mesothelioma develops in the abdominal area, pericardial mesothelioma develops in the cardiac (heart) area, and testicular mesothelioma develops in the male genital area. Pleural mesothelioma is the most common, making up approximately 75% of the cases.

Causes of Pleural Mesothelioma

Asbestos is the major cause of pleural mesothelioma, and was utilized for many industrial and household applications over the last century and a half. The mineral was advantageous to use in manufacturing processes. In the early 20th century, it was discovered that it posed significant health risks to people who were exposed to asbestos. Employers as varied as industrial plants to the United States Navy were aware of these dangers, but did not inform their employees and did not keep them from being exposed to the minerals. In the late 1980s, asbestos was banned in the U.S., barring a few highly regulated applications.

Latency Period

When someone is exposed to asbestos, fibers become embedded in the body. They aggravate the cells and result in cancerous growths. Someone who has undergone exposure may live for several decades without developing any symptoms. The latency period of mesothelioma can be anywhere from 20 to 50 years.

Symptoms of Pleural Mesothelioma

Indicators of pleural mesothelioma are frequently mistaken for symptoms of minor ailments at first, which can delay diagnosis. The symptoms include:

• Fatigue
• Persistent coughing, usually dry or raspy
• Coughing up blood (hemoptysis)
• Back or chest pain
• Swelling
• Development of lumps under the skin on the chest
• Perspiration
• Difficulty with swallowing (dysphagia)
• Hoarse voice
• Unexplained weight loss
• Night sweats or fever

Pleural Mesothelioma Diagnosis

Pleural mesothelioma, along with other forms of this cancer can be very difficult to diagnose. Thanks in part to the latency period, along with the issue that mesothelioma shares similar symptoms with other, more common illnesses, pleural mesothelioma is very regularly mistaken for less threatning diseases such as pneumonia.

Taking the patient's symptoms into consideration, a physical examination, samples from fluid and tissues, and imaging can help to diagnose pleural mesothelioma. Additionally, the location of the tumor is confirmed when a patient undergoes imaging tests such as x-rays or  CT scans.

The cancer can spread to other parts of the body in a process known as metastasis. Physicians use what is known as “staging” of the disease to indicate the extent to which the tumor has spread, and to categorize its size. The staging systems include the Butchart System, the TNM System, and the Brigham System.

Treating the Disease

After diagnosis, the patient and doctor should discuss treatment options, which will take into consideration the patient’s desires, in addition to other factors. Radiation, surgery, and chemotherapy are the most common treatments.

Radiation can be used either internally, from within the body, or externally, from outside the body. Radiation in general can destroy malignant cells, but it is not seen as the best choice for mesothelioma treatment. Chemotherapy involves the use of drugs to destroy the malignancy. This type of therapy can be used in cases in which the disease has spread or has come back after remission. Surgery is a good option if the cancer is caught in an early stage and the tumors can be removed. Often, patients will receive a combination of these treatments as a multimodal attack agaisnt this disease.

One kind of surgery, palliative surgery, is used simply to relieve the suffering the patient experiences while the disease runs its course; another version is done to prolong the life of the patient. Breathing difficulties can be relieved by draining fluid buildup, known as a pleurocentesis, or through injections of drugs or other substances to keep fluid from accumulating, known as pleurodesis. These treatments for pleural mesothelioma can help prolong a patient’s life, but they do not cure the disease.

Additionally, patients may be interested in seeking alternative treatment methods. These approaches are not approved to cure cancer, however, research has shown that when used in combination with conventional treatments, they can work as a pain or stress relief and often elongate a patient's life expectancy. Some alternative therapies include yoga, Reiki, massage therapy and pet therapy.

More and more, research is done to help find a cure for this terminal disease. Since pleural mesothelioma is the most common form of the cancer, more studies are done about this cancer, hence more knowledge is readily available to patients and doctors alike.

Prognosis for Pleural Mesothelioma

Early detection of pleural mesothelioma is essential and greatly correlated with the life expectancy. If a patient is diagnosed with mesothelioma in an early stage, they have a greater prognosis compared to those in more advanced stages.

Cancer Research UK shows that only ten percent of all pleural mesothelioma cases will survive for three to five years and eight percent will live longer than five years. They do mention that some reports quote survival rates of up to 50% after two years, proving the range of survival time is very wide. It is important to remember that every cancer case is unique and these statistics may not accurately mirror an individuals situation. As stated by Cancer Research UK,  "No statistics can tell you what will happen to you. Your cancer is unique. The same type of cancer can grow at different rates in different people. The statistics cannot tell you about the different treatments people may have had, or how that treatment may have affected their prognosis. There are many individual factors that will affect your treatment and your outlook."

While it is difficult to detect the cancer so early due to the latency period where symptoms do not usually arise for 20 to 50 years, if an individual has had prior asbestos exposure, they should get physical examinations regularly as a precautionary measure. For those who discovered this cancer in a late stage, palliative treatment options are usually recommended. These treatments will not cure the cancer, however they are designed to relieve pain and discomfort that goes along with the disease as a means of improving the patient's quality of life.

References:

American Cancer Society

National Cancer Institute

Cancer Research UK

Cancer Research UK Statistics