Clapper, Patti, Schweizer and Mason

Malignant pleural mesothelioma (MPM) is a fatal form of non-small cell lung cancer that occurs in approximately 3000 people annually in the United States alone.  As with most lung cancers, mesothelioma is often diagnosed only after it has reached an advanced stage.   MPM is difficult to diagnose as well as to treat, with survival rates past two years being rare, although clinical progress over the last few years has advanced knowledge of and treatments for the disease.  Targeted therapy is one area being researched that holds promise.

There are three treatments that are considered to be the standards:  surgery, chemotherapy and radiation.  After patients go through one or more of these initial treatments, there is no agreed upon standard course of action.  Any further therapeutic options must take into consideration any risks that may outweigh the benefits.   Some factors for treating physicians to consider are:

• Histologic characteristics of the tumor
• Individual patient history and past treatments administered
• Goals of therapy
• Risks versus benefits to any further treatments

Targeted therapies, using anticancer drugs that interfere with specific pathways where cancer cells grow and proliferate, has shown to improve outcomes for some mesothelioma patients.  Some more common drugs that specifically target mesothelioma cells are Avastin and Tarceva, with others still under investigation and not yet approved for treatment.  Research continues in hopes of not only discovering the best ways to use these drugs but also to predict which patients will show improved response rates. 

Targeting agents work by specifically targeting areas within the body and preventing new malignant cell growth.  Bevacizumab (Avastin, Genentech) is a monoclonal antibody drug that targets the blood vessels that supply tumors with proteins, oxygen and glucose needed for cancer cells to grow.  The risk of Avastin is the known side effect of increased bleeding, and therefore use must be weighed against other factors as well.  Erlotinib (Tarceva) specifically targets mesothelioma cells by interfering with proteins and receptors needed for continued malignant growth.  Tarceva however has only been shown to be effective when not given in conjunction with chemotherapy.

Other drugs are continually being researched.  The key is to find ones where overall survival rates are extended and that carry the least risk of treatment-related deaths.  If you have been diagnosed with mesothelioma and think this type of therapy might be of benefit, consult with your oncologist and also visit the National Cancer Institute for a current listing of clinical trials that may be going on in your area.