When cancer strikes the lining of the lungs - otherwise known as the pleura - the disease that results is referred to as pleural mesothelioma. Technically speaking, the pleura is a sac which contains the lungs as well as a thin membrane known as the mesothelium, which secretes a vital fluid that enables the lungs to expand and contract during the breathing process.
Indeed, pleural mesothelioma is the most common of the 3 types of mesothelioma, which also include the peritoneal and pericardial varieties of the disease. More than 75% of all diagnosed mesothelioma cases affect the pleura.
How Does Pleural Mesothelioma Develop?
When an individual is exposed to asbestos on a regular basis, whether it be through job-related activity or other environmental issues, inhalation of loose, airborne asbestos fibers can occur. These fibers travel to the lungs and become imbedded in the lung lining, outside of the lungs and inside the ribs.
When these jagged particles settle in the pleura, they cause inflammation. The inflammation, in turn, can lead to dangerous cancerous tumors. In some cases, those who've inhaled asbestos fibers will first develop the less-severe asbestosis, followed by mesothelioma several years later.
Upon diagnosis, patients usually exhibit multiple tumor masses affecting both the visceral (further from the lung) and parietal surfaces (closer to the lung) of the pleura. The parietal surface is more often affected than the visceral surface, and the right lung, due to its larger size, often suffers more damage than the smaller left lung. In addition, more asbestos tends to settle in the lower lungs than the upper lungs.
These tumors often grow quickly in size and can cover the entire lung cavity, making it very difficult to breathe and causing excruciating pain. Also, in the advanced stages of pleural mesothelioma, the cancer may spread to other nearby organs, including the heart, abdomen, and lymph nodes.
Pleural Mesothelioma Symptoms
It's not always easy to diagnosis pleural mesothelioma by examining its symptoms. All too often, the symptoms of the disease may resemble those of other more common illnesses, including something as simple as the flu, a cold, laryngitis, pneumonia, or whopping cough. It often takes weeks or even months before a correct diagnosis is made, and because the disease usually takes between 20 and 50 years to surface, past exposure to asbestos often doesn't come to mind when attempting to make a diagnosis or when a patient is giving a medical history.
Common symptoms of pleural mesothelioma often include:
- Chest pain
- Shortness of breath
- Fluid around the lungs (pleural effusion)
- Hoarseness or difficulty speaking
- Blood clots (less common)
Chest pain is usually the first indication of a problem, caused by the growing tumors that enlarge the pleural space and cause it to fill with fluid. Such chest pain is often mistaken for heart problems and many yet-to-be-diagnosed mesothelioma victims believe they are having a heart attack or suffering from heart disease.
The discomfort caused by the above symptoms can also result in loss of appetite and weight loss. Once mesothelioma is diagnosed, it's important for patients to maintain good eating habits in order to better combat the disease.
Diagnosis and Treatment
Ultimately, a definitive diagnosis of malignant pleural mesothelioma is achieved by the use of sophisticated x-rays such as CT scans and MRI, as well as biopsy, the sampling of tissue or fluid around the lungs. Scans can reveal the presence of pleural effusion and biopsies, preferably a needle biopsy, can complete the diagnosis. While somewhat uncomfortable, this test is quick and offers a good success rate for accurate diagnosis.
Because pleural mesothelioma is often so difficult to diagnose, the disease is most often in an advanced stage when discovered. That makes mesothelioma treatment options limited. Only a handful of mesothelioma patients afflicted with this form of the disease are candidates for surgery to remove tumors, especially since the tumors are often large and widespread by the time of diagnosis. Surgical resection may be an option later, if the oncologist thinks the removal of a lung would benefit the patient.
More often, pleural mesothelioma patients are treated with radiation or chemotherapy. While advancements are being made in the treatment of the disease, especially with chemotherapy, such treatment is often palliative - meant to relieve the symptoms of the disease, make the patient more comfortable, and improve the patient's quality of life during the months ahead.
Some doctors opt for what is commonly known as multi-modal therapy, which is a combination of two or more therapies, usually chemo and radiation. Recent research has also prompted experimentation with different combinations of chemotherapy drugs, resulting in positive outcomes when certain ones are used at the same time.
Currently, the prognosis for those diagnosed with pleural mesothelioma is not good. Many patients die within six months of diagnosis, some last up to a year, but few survive much beyond that length of time. Clinical trials are constantly underway in hopes that a cure for the disease or a way to further prolong the life of a pleural mesothelioma sufferer will be discovered.
- American Cancer Society. Detailed Guide What is Malignant Mesothelioma?http://www.cancerhelp.org.uk/help/default.asp?page=4465
- Cancer Help, UK.http://www.cancer.org/docroot/CRI/content/CRI_2_4_1X_What_is_malignant_mesothelioma_29.asp?rnav=cri
- American Cancer Society. Detailed Guide: Malignant Mesothelioma Radiation Therapies.http://www.cancer.org/docroot/CRI/content/CRI_2_4_4X_Radiation_Therapy_29.asp?sitearea
Last modified: April 15, 2011.