Clinical:Mesothelioma

Mesothelioma is a cancer that affects the lining of body cavities. It may develop in the pleurae, the peritoneum, or the pericardium.

Mesothelioma arises from exposure to asbestos, either through occupational or second-hand/inadvertent contact. The latency period from exposure to onset of symptoms may be as long as 50 years.

Physicians who practice in areas where asbestos was mined, processed or used in manufacturing have an increased likelihood of seeing patients with this deadly cancer. However, because of the long latency between exposure and symptoms and the tendency of people to relocate, patients may present with mesothelioma even in areas that do not have a high incidence rate or a history of asbestos use.

In view of mesothelioma’s rapid lethality, early diagnosis and prompt intervention are critical to survival.

Signs and Symptoms

Mesothelioma is difficult to diagnose, as the initial symptoms may mimic more routine and less serious disorders. But with an average life expectancy of 4 – 14 months, prompt, accurate identification is paramount. Be alert for:

• Persistent pain in the lower back, lateral chest, or abdomen.
• Dyspnea on moderate to minimal exertion.
• Pneumonia-like symptoms unresolved by antibiotics.
• Difficulty swallowing.
• Persistent cough or hoarseness.
• Drenching night sweats.
• Unexplained fevers.
• Leukocytosis.
• Thrombocytosis.
• Upper body or facial edema.
• Abdominal distention and/or bowel changes.
• Nausea, vomiting, and/or loss of appetite.
• Increase in or appearance of gastric reflux.
• Distant breath/bowel sounds on auscultation.
• Reduced activity tolerance.

How to optimize your patient's prognosis

• Be alert for symptoms that do not resolve.
• Obtain detailed work, geographic, & family histories.
• Order the appropriate tests promptly.
• Consult with mesothelioma specialists.
• Contact the Meso Foundation for up-to-date clinical information.

Essential questions to ask regarding patient's history

Ask your patient the following:

• Is it possible you were exposed to asbestos in the past?
• Did anyone in your family work with or near asbestos?
• Did you ever serve in the navy?
• Did you or anyone in your family work as an electrician, carpenter, plumber, auto mechanic, pipefitter, boiler
• worker, or contractor?
• Did you ever work in a public service job such as fireman,policeman, EMT, or disaster volunteer?
• Did you live or work in an area near asbestos mining or manufacture?
• Did you live or work in a building built prior to 1989 that was in disrepair or underwent remodeling?

Diagnostic Tests

Because of the time lapse from exposure to diagnosis, and because many patients may have been exposed unknowingly, it is vital to confirm findings via appropriate testing.

XRAY – not useful for tumor detection, but pleural plaques are highly suggestive of asbestos exposure.

CT/CAT Scan – tomography may detect tumors and membraneous thickening.

MRI – magnetic resonance may detect tumors and membraneous thickening.

Biopsy – definitive diagnosis requires obtaining a biopsy specimen, and performing appropriate immunohistochemical stains.

VATS (not open thoracotomy) – video-assisted thoracoscopy should be used for examination, to guide biopsy, and to obtain adequate tissue. Open thoractomy should only be used with great caution.

Serum assay – currently, a blood test to detect mesothelioma bio-markers is available on a humanitarian basis. Contact the Meso Foundation for further information.

Important note about pleurodesis

Once the standard intervention for patients with pleural effusion, pleurodesis should be used with extreme caution. Due to recent advances in the treatment of pleural mesothelioma, a pleurodesis may actually reduce your patient’s ability to pursue intrapleural modalities and lung-sparing surgical options.

What else should doctors know?

Mesothelioma, typically a very aggressive cancer, was long considered to be resistant to all therapy. Upon diagnosis, patients were commonly told simply to get their affairs in order and prepare for death.

Understandably, your patient may be devastated upon learning their diagnosis. But there is hope. During the past five years, significant strides have been made in treatments to extend survival, and the Mesothelioma Applied Research Foundation is funding one million dollars per year in basic and clinical research aimed at further improving treatments. A new FDA approved chemotherapy, Alimta, in combination with platinum based drugs, has stabilized or decreased tumor burdens in many patients. Treatment using multiple modalities – surgery, chemotherapy, and radiation – has produced survivals of a decade or more. Other treatments utilizing novel modalities such as genetic manipulation and cytokinines are also being developed.

Epidemiology

Incidence

Unfortunately, incidence of mesothelioma is rising. Once considered to result solely from chronic occupational exposure to asbestos, mesothelioma is now known to involve nonoccupational populations as well. Research by both the EPA and WHO has concluded that any asbestos exposure may be sufficient to induce disease. Mesothelioma affects individuals regardless of race, gender, or age. It can arise in children who were exposed to asbestos in infancy.

Asbestos use is not banned in North America, and remains a component of multiple commercial products. Because it does not biodegrade, asbestos from former uses persists in the environment. Once widely used in construction products, asbestos is found in homes and buildings across the nation. And when older structures are damaged, as they were on 9/11 and during Hurricane Katrina, fibers may be liberated to expose surrounding communities.

Specialist Consultation

Your patient’s chances for survival will be enhanced by working with an expert. A complete directory of surgeons, oncologists, radiologists, and pathologists who specialize in mesothelioma is available from the Mesothelioma Applied Research Foundation.

The Mesothelioma Applied Research Foundation is the nonprofit collaboration of patients and families, physicians, advocates, and researchers dedicated to eradicating the life-ending and vicious effects of mesothelioma. The Foundation promotes research, supports patients and caregivers, and disseminates the latest clinical information. The Foundation provides frontline physicians with the tools to improve patient outcomes, and conducts annual Symposia to bring together research scientists, healthcare providers, and patients and families from around the globe.

The Foundation’s Medical Liaison maintains complete directories of national and regional mesothelioma specialists, centers of expertise for mesothelioma treatment, ongoing clinical research trials, and the latest available treatments, and is available to you or your patients to help identify resources for consultation and collaboration.