New Treatment for Glioblastoma

Glioblastoma, the most common type of brain cancer, is serious tumor. With even the best prognosis and intense treatment, the average life expectancy for a patient is about 15 months. This bleak outlook is due to the lack of effective drugs and the inability of potentially effective drugs to cross the brain-blood barrier. This phenomenon is created by the cells around the capillaries in the brain, which are so tightly packed that many molecules, such as harmful drugs or microbes, are unable to gain purchase in the brain. Unfortunately, this makes treating brain cancer, or other neurological diseases, more difficult than in other parts of the body.

The current treatment for Glioblastoma, is surgery to remove the tumor, followed by radiation and then chemotherapy with the drug Temodar, which is believed to be able to cross the brain-blood barrier. Unfortunately, as previously stipulated, this is fairly ineffective, and in many cases, new tumors sprout up quickly following, or even during, treatment. However, a clinical trial is currently underway to attempt to find a new way to treat Glioblastoma. This approach involves some of the traditional methods mentioned above, as well as combining some old technology with new medication.

In this new approach the tumor is removed, although that may change with the effectiveness of the treatment, and then a microcatheter is threaded, via an artery in the groin, up into the specific area of the brain that the tumor was in. Then, the cancer drug is infused with another drug called Mannitol, the secret to getting through the brain-blood barrier. Mannitol, discovered some 30 years ago, takes some of the water out of the cells, making them shrink, creating gaps between the cells, allowing the drug molecules are able to move through and into the area of the brain they need to get to. Not only does this allow for a higher dose to get into the brain, over 50 times more than intravenously, it also allows for more specific placement of the dose, which may potentially decrease the adverse effects of the drug on the rest of the brain.

What is also interesting, is the new drug that is being used in this study, called Avastin, works in a manner similar to that of Endostatin, the drug featured in Cancer Warrior. This drug prevents angiogenesis, which prevents cancer cells from getting nutrients, preventing the tumors from getting larger. However, unlike Endostatin, Avastin appears to actually work, not only slowing tumor growth, but actually making tumors disappear.

This new delivery system does not appear to have may ethical issues. The patients that are being treated would die in about four and a half months without treatment, and the drugs that are being used have all been approved for human use and the techniques are fairly widespread and used in many other situations. The only potential moral dilemma, is in the actual development of the drug and whether it is moral to test on animals, as I am sure they did, before the drug is used on humans. Although this has nothing directly to do with the actual operation of this clinical trial, it is a precursor that must be taken into account before using a drug because using it supports the approach of animal testing before human testing.

Glioblastoma Presentation

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Sources:
http://www.nytimes.com/2009/11/17/health/17tumor.html?_r=1&sudsredirect=true
http://en.wikipedia.org/wiki/Glioblastoma_multiforme
http://www.avastin.com/avastin/index.jsp?q=Avastin
http://www.asahi-intecc.com/medical/product/ivr_mc.html
http://www.drugs.com/cdi/mannitol.html

Dylan and Cassie