Clapper, Patti, Schweizer and Mason

Mesothelioma is also sometimes referred to as Malignant Pleural Mesothelioma (MPM) or Diffuse Malignant Mesothelioma (DMM). All forms of mesothelioma are associated with exposure to asbestos and have very poor prognosis with a median survival time of less than a year. Epidemiological studies have shown that asbestos fibers make up the main risk factor occupationally, causing induction of mesothelioma.

 

For mesothelioma, epidemiological studies look at how often the disease occurs in different groups of people and geographical locations and tries to determine why. The intention of such studies is to prevent mesothelioma by establishing strategies to avoid risk and also to help guide the management once the disease is present.

 

Mesothelioma is a type of cancer that affects the lining of the lungs, heart or abdomen. The majority of mesothelioma arises from the pleural (lung) cavities. Mesothelioma is caused when asbestos is inhaled or ingested into the body, where it then lodges in the protective sacs around the internal organs. Symptoms of the disease do not begin to appear until decades later, making mesothelioma very difficult to diagnose in early stages. Although much research is being conducted, treatments have not been very effective and there is no known cure.

 

Front line treatments are considered to be standard therapies, and in the case of mesothelioma, include surgery, chemotherapy and radiation therapy. Due to the inefficacy of these, second line treatments and multi-modality approaches are also being explored. Second line treatments are used in clinical practice when patients have gone through first treatments and are still healthy even in the face of disease progression. 

 

A recent article published in Cancer Treatment Reviews (February 2010), analyzed data regarding second line therapy of patients with malignant pleural mesothelioma to review any advances and look forward to future treatment possibilities.

 

The established standard treatment for mesothelioma patients is now considered to be a combination of a multi-targeted antifolate known as pemetrexed along with a platinum compound, most often cisplatin but sometimes carboplatin. There is no standard second line chemotherapy established at the time, especially for patients that have already been treated with pemetrexed or cisplatin. For patients that are chemotherapy-naïve, pemetrexed treatment is often used as a second line approach.

 

Exploration of novel targeted agents, such as angiogenesis inhibitors, vascular targeting agents, histone deacetylase (HDAC) inhibitors, and ribonucleases enzyme regimens, have shown some emerging positive results. Many of the new therapies are intended to systemically treat mesothelioma, with direct anti-tumor effects on cancer cells and inhibiting or interrupting signaling pathways.

 

The authors point out that in reviewing the results of previous and ongoing studies, there may be some bias to outcome since the populations chosen to participate may have been more selected with more favorable conditions, such as age, history, progression levels, etc. The review also looked at how well different second line treatments were tolerated, noting toxicities, side effects, and outcomes. 

 

The authors of the article have done thorough evaluation of current and ongoing research and conclude that second line therapies testing new agents warrant further investigation and patients diagnosed with mesothelioma should be encouraged to participate. 

 

Pemetrexed continues to be evaluated as a good chemotherapeutic agent for first line treatment as well as second line treatment for pemetrexed naïve or selected pre-treated patients. The article also recommends single agent chemotherapy with vinorelbine as an option to for pemetrexed pre-patients not able or eligible to participate in experimental studies.   

 

For more information on second line trials and correlative studies, visit the National Cancer Institute, or talk to your treating oncologist or mesothelioma specialist. Most second line studies are aimed to improve symptoms, overall survival and response rates, time to progression, and quality of life. If you have been diagnosed with mesothelioma, such studies are worthy of exploration and possibly participation.