Q&A: Focus on Mesothelioma

Mesothelioma is a rare cancer that starts in the cells lining certain parts of the body, especially the chest and abdomen. Primary risk factors include workplace exposure to asbestos.

Anne Tsao, M.D., associate professor in MD Anderson's Department of Thoracic/Head and Neck Medical Oncology and director of its Mesothelioma Program, answers questions about mesothelioma. 

What is mesothelioma?
Mesothelioma is a cancer that arises from mesothelial cells, which normally make up the lining around our organs. Mesothelioma can originate from the:

• Pleura (lining around the lungs)
• Peritoneum (lining around the abdominal cavity)
• Pericardium (lining around the heart)
• Testes
  

Is mesothelioma rare?
In the United States about 3,000 cases of mesothelioma are diagnosed each year, and in Western Europe approximately 5,000. There is some speculation that the 9/11 event that destroyed the Twin Towers in New York City may lead to increased incidence of mesothelioma and other cancers in the first responders who worked in the affected site.

What causes mesothelioma?
Asbestos exposure is the most likely cause. In more rare situations, there is a theory that contaminated polio vaccines in the 1940s with simian virus 40 may have led to some cases, but this has never been proven. Recently, an inherited gene has been identified that may predispose certain families in the Cappadocia region of Turkey to the disease. Also, an additional gene mutation in BAP1 has been reported. This germline mutation can predispose people to melanoma as well.

What are the symptoms of mesothelioma?
It can vary, but the most common clinical symptoms are:

• Shortness of breath
• Cough
• Weight loss
• Fatigue
  

Many mesothelioma patients have a pleural effusion on their chest X-rays -- or fluid around their lungs. Anyone who has a history of asbestos exposure and any of the above symptoms should be evaluated for mesothelioma.

Are some individuals more likely to develop mesothelioma than others? If so, who?
Yes, people who have had occupational exposure to asbestos. Also, at risk are those who live or have lived with relatives working in occupations where asbestos fibers got on clothing that was worn home. Unfortunately, we do not have a simple lab test that can reliably tell us who will develop mesothelioma later in life. Currently, there are two serum tests under development to detect mesothelioma: osteopontin- and serum mesothelin-related peptide.

How is mesothelioma diagnosed?
It can be difficult to diagnose mesothelioma. Often, a chest X-ray is ordered and only shows a pleural effusion. A thoracentesis, a procedure to remove fluid from the space between the lungs and chest wall, is often unrevealing and doesn't show any malignant cells. In time, patients often develop a rind or mass. A tissue biopsy is required to determine whether this is mesothelioma, and certain biomarkers are used to confirm the diagnosis.

What are the main treatments for mesothelioma?
Depending on the patient's stage, chemotherapy, surgery, radiation and new novel targeted agents on clinical trials can be considered. For patients who have operable disease, we usually recommend multi-modality therapy with chemotherapy, surgery and radiation. At MD Anderson, we have clinical trials that offer the addition of novel agents that target protein pathways in mesothelioma.

If a patient cannot receive definitive or curative-intent surgery, then we use systemic agents (chemotherapy or novel agents) and sometimes radiation to palliate symptoms of pain. Our clinical trials offer new agents in combination with chemotherapy. These are geared toward learning more about the disease so that, one day, we will be able to personalize cancer therapy to the molecular profile of each person's tumor.
    
What factors may affect a patient's prognosis and/or treatment options?
The most important individual factors are patients' weight, performance status and attitude. Also, having a supportive environment with family and friends is critical. As long as patients can maintain their weight, performance status and positive attitude, we can design a treatment option for them.

What research, if any, is being conducted at MD Anderson in regard to this disease?
We have clinical trials using novel agents in addition to standard of care for every setting in mesothelioma. We also have a robust translational/preclinical program that investigates new ways to target this cancer. Our mesothelioma program is unique and comprehensive because it is supported by a robust multi-disciplinary group. We have more than 60 physicians, research nurses, research staff and scientists -- who all treat patients and/or work in the laboratory -- focused on finding cures for this deadly disease.