As a young doctor who specializes in cancer treatment, I realize that, for many people, the types and prognoses of brain tumors are, upon first glance, quite overwhelming. My thoughts and prayers go out to Sen. Kennedy. His career has been historic; his legislative contributions immense; and his concern for progressive values will continue to inspire generations of young Democrats.
Sen. Kennedy first entered the MGH on Saturday with seizures, one of the most common presenting symptoms of malignant glioma (although certainly not the most common cause of seizures). Word today on the diagnosis and location of the tumor brings up a variety of questions:
- what type of malignant glioma is it? There are two major criteria which we use to classify malignant brain tumors. One is the grade---or how much the tumor looks like normal brain tissue. Grades run from 1-->4, with 1 being a tumor that most resembles normal brain. Length of survival correlates strongly with grade. The second criteria we use is histology--or what type of brain cell does the tumor most look like? Gliomas can be of 3 three general varieties: Astrocytoma (looks like astrocytes), Oligodendrogliomas (looks like oligodendrocytes) or a mix. Again, generally, oligodendrogliomas have a better prognosis.
- where is the tumor located? This is critical from a surgical perspective. Tumors located in areas like the brain-stem are generally inoperable, and only treated with chemotherapy or radiation. In the parietal and front lobes, tumors located in eloquent areas (areas responsible for speech,etc) are much more difficult to remove surgically without severely compromising a persons neurological function.
- what are the treatments? The mainstay of treatment is surgical resection of the tumor, at the MGH this would likely involve a great deal of computer assist. Following surgical resection, the person would likely undergo several weeks of radiation treatment, again with assist of advanced computer systems that can deliver the bulk of the dose to the tumor bed. MGH also has a form of radiation therapy known as proton therapy which can be highly targeted. Chemotherapy for brain tumors is still very much in its infancy. Tumors with certain types of genetic alterations respond to a chemotherapy known as Temozolomide. Experimental trials involving a variety of new, targeted agents are also underway and show some promise (Erlotinib, anti-angiogenic txs, etc).
Survival depends largely upon the grade and histology of the tumor. The most dangerous tumor with the shortest overall survival time is Glioblastoma Multiforme ( a grade 4 astrocytoma). Here 2 years would be quite impressive survival. Lower grade lesions can have survival on the average of years.
On the hospital--the Massachusetts General Hospital is a teaching hospital affiliated with the Harvard Medical School. In terms of brain tumors, it is one of the best in the world.
Again, my thoughts and prayers go out to the Kennedys.