Pleural mesothelioma is a type of cancer that affects the lining of the lungs called the pleura, according to Allaboutmalignantmesothelioma.com. Despite its location, it is not a kind of lung cancer, because it originates in the membranes, not the lungs; when this cancer is found in the membranes lining the abdominal cavity, it is called peritoneal mesothelioma.
Significance
In the United States, approximately 2,000 new cases of mesothelioma are diagnosed each year, according to the National Cancer Institute. Allaboutmalignantmesothelioma.com states that pleural mesothelioma accounts for nearly 75 percent of these diagnoses. It is mainly diagnosed in older individuals; the American Cancer Society says that three out of four people with mesothelioma are over the age of 65.
Risk Factors
The National Cancer Institute lists working with asbestos as the main risk factor for developing mesothelioma. They state that 70 to 80 percent of all cases of the disease occur in people with a history of exposure to the substance; but there are also a small amount of people who have not been exposed and still get the disease. Smoking does not increase the risk of developing mesothelioma, but if combined with asbestos exposure, the risk for disease significantly increases.
Symptoms
Symptoms of pleural mesothelioma can include chest pain, which can also manifest as shoulder pain; shortness of breath; unintentional weight loss, coughing and loss of appetite. In advanced pleural mesothelioma, the tumors grow rapidly and the space around the lungs expands and fills with fluid, causing discomfort or pain, according to Allaboutmalignantmesothelioma.com. Other symptoms include fever, fatigue, trouble swallowing, swelling in the face and arms, and muscle weakness.
Identification
In addition to a complete physical exam and medical history, a chest X-ray is typically the first test done if a constant cough or shortness of breath is present, according to the American Cancer Society. A CT scan can aid in diagnosing pleural mesothelioma, and give a clearer picture of the spread of the cancer and its location. A PET scan, MRI and blood work are also typically done to see if the cancer has metastasized, and to check blood counts and tumor markers. Biopsies of the tumor or the fluid around the lungs may be done to examine the samples for cancer cells to get a definitive diagnosis.
Staging
Once pleural mesothelioma is definitively diagnosed, it is staged. Staging involves classifying the cancer into different stages based on the spread and extent of the disease. This is done by the TNM system, according to the National Cancer Society. The "T" is the extent of the main tumor, the "N" represents lymph node involvement, or how many nodes are cancerous, and the "M" stands for any metastases, or spread to other organs. Staging helps with treatment planning and guides prognosis. For pleural mesothelioma, stages range from Stage I to Stage IV, in order of ascending severity.
Time Frame
By the time mesothelioma is diagnosed, it is typically at an advanced stage, according to the American Cancer Society. Average survival times for individuals with mesothelioma range between four to 18 months, and approximately 10 percent live five years or more after their diagnosis. Due to how rare the disease is, more specific survival rates broken down by stage or type of mesothelioma are not available.
References
- National Cancer Institute: Mesothelioma - Questions and Answers
- allaboutmalignantmesothelioma.com: Pleural Mesothelioma
- American Cancer Society: What are the key statistics about malignant mesothelioma?
- American Cancer Society: How is malignant mesothelioma diagnosed?
- American Cancer Society: How is malignant mesothelioma staged?
