A new clinical trial is seeking to better understand the possible benefits of altering a standard chemotherapy regimen widely used for mesothelioma patients. The chemotherapy in question, a combination treatment using both pemetrexed and cisplatin, has been used historically with patients suffering from mesothelioma of the pleural cavity, and has demonstrated varying levels of efficacy in different circumstances.
Mesothelioma is an aggressive, rapidly progressing and terminal cancer caused by exposure to airborne asbestos fibers. Upon accidental inhalation, asbestos fibers, due to their peculiar shape and microscopic size, pass through a majority of the body’s soft tissues including the lung walls with ease. They become arrested in a sticky tissue known as the mesothelium, however, and cause a scarring reaction which can lead to the development of malignant tumors. The disease takes anywhere from ten to fifty years to present from the time of initial exposure and shares symptoms with a variety of common ailments – two characteristics which make it particularly difficult to diagnose.
The clinical trial was performed by Southwest Oncology Group, a large clinical trial cooperative which is partially funded by the National Cancer Institute. Southwest Oncology Group enrolls more than 6,000 volunteers for such trials each year.
Cancerous tumors grow similarly to other tissues, that is, through cell division. This growth necessitates the development of blood vessels to provide the tumor with nutrients. The new trial included the use of chemicals designed to inhibit the growth of these blood vessels and subsequently limit the growth rate of the tumors themselves.
In addition to use of the traditional treatments pemetrexed and cisplatin, the new trial introduced a third chemotherapy drug known as cediranib maleate intended to control the growth of blood vessels within the tumor. The trial set out to determine both the efficacy of the new combined treatment, and the most effective dosage of the new additive in patients suffering from various stages of the disease.
The new treatment, currently in Phase I/II of testing, is being used in patients who as of yet have not been subjected to other forms of treatment in order to better isolate the results of the study. Once completed, Southwest Oncology Group hopes the study will establish a more effective formula for chemotherapy treatment in patients with pleural mesothelioma.