Doctors treating unresectable mesothelioma have traditionally used chemotherapy to help patients reduce symptoms, decrease pain and help maintain their quality of life. Unresectable mesothelioma is a type of cancer that cannot be treated with surgery. This can be because the mesothelioma has spread to other parts of the body (called metastasis), or the type of cancer itself makes it difficult to remove from the body. For these cases, chemotherapy has been the mainstay of treatment.
Clinicians have usually relied on a combination of two chemotherapy drugs together: cisplatin and pemetrexed (Alimta®). This drug duo became the most widely used treatment regimen and was the gold standard of treatment.
Recently however, the National Comprehensive Cancer Network (NCCN) released new guidelines recommending the addition of a new drug to the group called bevacizumab, which helps to bolster the effects of the current treatment regime.
A New Drug to Fight Mesothelioma
Instead of using brand new drugs or new treatment protocols, the addition of bevacizumab is meant to enhance the action of cisplatin and pemetrexed. These two chemotherapy drugs work by stopping the rapidly dividing cancer cells in the body; the addition of a third drug (bevacizumab) has been shown to be even more effective.
Bevacizumab is special because it doesn’t work like other chemotherapy drugs. One of the reason cancer cells grow so quickly is they are able to grow more blood vessels than other cells in the body, which allows them to attract more nutrients and grow at a very fast rate. Bevacizumab works by slowing the growth of these blood vessels, thus depriving cancer cells of their blood supply. So while Bevacizumab is not a classic chemotherapy drug, it is being used alongside them to fight the cancer cells using another attack method.
According to the NCCN, research has shown that by adding bevacizumab as part of a treatment program, survival rates for unresectable mesothelioma can be extended. Studies have shown that overall survival was increased by almost three months when using bevacizumab, rather than the standard cisplatin and pemetrexed regimen.
The NCCN updates their guidelines annually, with additional interim updates taking place as needed throughout the year. However, this particular update marks a significant step forward for mesothelioma treatment, as the cisplatin and pemetrexed combination (without bevacizumab) has been the standard of treatment for unresectable mesothelioma for many years.“The panel felt that the new treatment guidelines were equivalent to cisplatin and pemetrexed,” said Joan McClure, Senior Vice President of Clinical Information and Publications for the NCCN. McClure added that the new treatment is about equally as effective as the former treatment, though it could be a little more toxic and has less data backing it. Nonetheless, McClure said it “was an option that people should have available to them.”
While bevacizumab is recommended for use in most cases of unresectable mesothelioma, those who are unable to tolerate bevacizumab or are not suitable candidates for receiving it will still be treated with the traditional medicines. Patients unable to use bevacizumab includes those with poorly controlled high blood pressure, and patients with a history of blood clots.
Bevacizumab and Increased Survival
Mesothelioma is one area of cancer research in which researchers are always looking for ways to increase survival rates, prolong life expectancy, and let patients with maintain their quality of life. The addition of bevacizumab is one way in which researchers and practitioners hope to do exactly that.
When the NCCN made the recommendation to add bevacizumab to the group of chemotherapy drugs already being used to treat unresectable mesothelioma, they made that decision based on scientific research and the findings of clinical trials. One of those trials was a well-known study funded by Intergroupe Francophone de Cancérologie Thoracique. This study looked at the effects of adding Bevacizumab to the two existing drugs in the treatment of unresectable mesothelioma and they found that a patients overall survival was significantly longer with the addition of Bevacizumab.
Taking this a step further it is possible that even more gains can be made. In the future, bevacizumab and other drugs like it can be started even earlier in the treatment cycle to help improve the prognosis of mesothelioma patients.