Clapper, Patti, Schweizer and Mason

Mesothelioma is an aggressive and universally fatal and incurable cancer caused by exposure to asbestos.  Patients diagnosed with malignant mesothelioma are often in their 50’s to 80’s at time of diagnosis since there is a long latency periods of ten to forty years from time of exposure to development of disease.  Standard treatment for mesothelioma includes surgery, chemotherapy and radiation therapy.  Unfortunately, none of these modalities have been very effective interventions.

 

There are three main histological types of mesothelioma are:

·         Epithelial (over 60%)

·         Sarcomatoid (10%), and

·         Biphasic or mixed

Epithelial is the most common, and some studies have shown that is has the best prognosis, however also can be the most resistant to chemotherapy agents.   Sarcomatoid has the worst prognosis of seven months or less.

 

Chemotherapy is almost always used as treatment when a patient is diagnosed with malignant pleural mesothelioma, a form of non-small cell lung cancer.  The three main drugs used in chemotherapy are cisplatin, gemcitabine, and vinorelbine.    Sometimes these drugs are used alone or in combination, and then often surgery or radiation therapy is also involved.  When all three drugs are used it is often referred to as the PGV regimen, and initial clinical trial results show some success with this triplet approach.

 

The purpose of any regimen, whether using just one agent or all three, is not to cure but to increase median survival time (MST) and improve overall quality of life for mesothelioma patients.  The median survival time for mesothelioma is quite poor, from 4 – 12 months.  Quality of life is greatly decreased due to painful and recurring symptoms of chest pain, difficulty breathing, fatigue and weight loss. 

 

Despite small increases in survival times, a significant number of mesothelioma tumors show extreme to intermediate resistance to all three drugs, whether used solitarily, in double combination, or triplet regimen.  Resistance is even more in epithelial tumors.  Because of this, active research and new approaches are essential to discover better, more effective treatments for mesothelioma.