Mesothelioma: Risk Factors and Treatment

Mesothelioma is a cancer that can arise from the cells lining the lungs or abdominal cavity. This is a rare cancer which is strongly related to a history of exposure to Asbestos. Mesothelioma of the pleura, which is the lining of the lungs is the most common form. In the United States, there are around 3300 cases per year with declining rates as a result of control of asbestos exposure.

Risk factors for development of Mesothelioma

• Asbestos exposure
• Ship building
• Lining of brake pads
• Insulation material
• Roofing and piping material
• Radiation exposure

The cancer develops many years to even decades after exposure to asbestos, usually after the exposure is no longer present.

Symptoms of Mesothelioma

The individual experiences a gradual worsening of the following symptoms which occurs due to a growth on the lining of the lungs which may be associated with fluid surrounding the lungs as well

• Chest pain
• Shortness of breath
• Cough
• Night sweats
• Weight loss
• Fatigue

The cancer can, in advanced stages, spread to the bone, liver or nervous system causing bone pains, jaundice and weakness or numbness.

Diagnosis of Mesothelioma

The diagnosis is suspected based on the history of symptoms and from a report of exposure to asbestos in the past. Following a physical exam, the doctor would confirm the diagnosis based on the following tests

• Chest X ray
• Computed Tomography (CT) of the chest reveals plaque like growth over the lungs and may also show fluid in the spaces around the surfaces
• Positron Emission Tomography (PET) is an additional imaging test that may be done to look for extensive disease
• Biopsy of the tumor: A piece of the tumor is examined under a microscope to confirm the diagnosis. The tissue is obtained through bronchoscopy (a tube with a camera inserted through the airway into the lungs) or surgically through the chest wall.

Management of Mesothelioma

The treatment of the tumor is based on the stage of the disease which is in turn determined by the spread of the cancer on imaging studies. The general treatment options are as follows

• Chemotherapy: All patients with mesothelioma receive chemotherapy as a combination of 2 or more drugs
• Surgery: A small group of patients may be eligible for surgical resection of the tumor with a possibility for cure. Palliative surgery is an option for extensive spread of the tumor where reduction in size may provide symptomatic improvement
• Radiation therapy: This may be provided alone for symptomatic benefit or in combination with chemotherapy and surgery.

Complications of Mesothelioma

• Respiratory distress
• Cardiac involvement with life-threatening arrhythmias (abnormal heart rhythms) and heart failure
• Extension to the abdomen with bowel obstruction
• Stroke from tumor progression to blood vessels

Prognosis of Mesothelioma

Due to the slow progression of the disease, it is often missed initially and is diagnosed only in late stages. This makes the treatment more challenging and very few patients are cured of cancer. Patients, in general, survive for only about a year after diagnosis. Death occurs due to complications associated with the spread of cancer to surrounding structures.

References

• Teta MJ, Mink PJ, Lau E, Sceurman BK, Foster ED. US mesothelioma patterns 1973-2002: indicators of change and insights into background rates. Eur J Cancer Prev. 2008 Nov;17(6):525–34.
• ATSDR. Asbestos Toxicity: Where Is Asbestos Found? | ATSDR – Environmental Medicine & Environmental Health Education – CSEM [Internet]. [cited 2018 Jun 16]
• Kindler HL, Ismaila N, Hassan R. Treatment of Malignant Pleural Mesothelioma: American Society of Clinical Oncology Clinical Practice Guideline Summary. J Oncol Pract. 2018 Apr;14(4):256–64.