Mesothelioma Breath Test for Diagnosis?

Diagnosis of malignant pleural mesothelioma is difficult and can often be mistaken for pneumonia, leading to a delay in treatment. But there is a new hope. Diagnosing mesothelioma with a simple breath test may be on the horizon.

A study recently published in September 2011 (e-pub ahead of print), has presented a novel test which analyzes exhaled breath using an electronic nose to detect malignant pleural mesothelioma. The concept for this analyzer was based on previous research that demonstrated electronic devices which could analyze exhaled breath and distinguish constituents in the breath which were characteristic in patients with lung cancer, due to characteristic “breath prints”. The recently reported study in malignant pleural mesothelioma patients demonstrated that the breath in patients exposed to asbestos who had malignant pleural mesothelioma, could be distinguished from the breath of patients exposed to asbestos who did not have malignant pleural mesothelioma, and from the breath of control patients who were not exposed to asbestos, with a sensitivity of 92.3% and specificity of 85.7%. Not a perfect test. But a great start.

These results suggest that such an analyzer may be beneficial in diagnosis of malignant pleural mesothelioma or may be used as a screening tool to determine patient groups that may require further diagnostic testing. This preliminary research is very encouraging. Follow up validation tests will be the next steps that will need to be conducted prior to integrating into current diagnostic practices for malignant pleural mesothelioma.

Mesothelioma and Other Asbestos-Related Lung Diseases – Epidemiology
Meso is just a tough disease. The World Health Organization estimates that 90,000 people worldwide die annually from asbestos related disease. Asbestos inhalation can lead to a variety of respiratory diseases including malignant mesothelioma, interstitial pulmonary fibrosis, pleural plaques and asbestos-related lung cancer. Mesothelioma is more common in men than women at a ratio of 5:1. The American Cancer Society estimates that 75% of patients diagnosed with mesothelioma are over the age of 55. Mesothelioma is more prevalent in the elderly due to the long latency of asbestos related disease. The occurrence of asbestos-related diseases is expected to increase over the next 20 years due to the ageing population and long latency of the disease.

Prognosis is dependent on several factors include overall health of the patient, timing of diagnosis, stage of disease, and whether or not it has metastasized to other areas of the body. Patients with late stage disease generally are given an life expectancy of three to six months. The five year survival rate (percentage of people expected to survive 5 years or longer) is approximately 10%. This is in large part due to delays in diagnosis.

Current Diagnosis and Future Directions
Diagnosis now for meso is not easy. It is estimated that 25% of patients show symptoms of pleural mesothelioma for 6 months or longer before they are diagnosed. Unfortunately symptoms do not occur until the pleural mesothelioma reaches advanced stages. Therefore, earlier detection is key to a more favourable outcome. Various procedures may be used in diagnosing patients, including but not limited to: chest x-rays, CT scans, throracoscopy, bronchoscopy, mediastinoscopy and biopsies. Some of these procedures are very invasive and carry a high risk for complications. As a result, recent research has been focused on finding less invasive, novel tests for more accurate and early detection. Some bodily fluids have been shown to have an association with malignant pleural mesothelioma. It has also been shown that exhaled air contains over 3000 volatile organic compounds which may be used to identify the presence of respiratory disorders.

It is still early, but this test provides new hope for treating a very difficult disease.

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