Brain Tumors: In a Nutshell

Jan. 11, 2020

We are sharing the basics of brain tumors, including the treatment and removal process.

When a person is diagnosed with a brain tumor through an MRI, in most cases, the neurosurgeon performs a biopsy to obtain a neuropathological diagnosis.

But what does this actually mean? We classify brain tumors by grades, unlike cancer in the rest of the body, by looking at the tissue under a microscope. Grade I tumors are benign, and grade IV tumors are malignant.

However, even benign tumors can pose risks, depending on their location in the brain. For example, a grade I tumor near the optic nerve (optic nerve gliomas or meningiomas), or the vestibulocochlear nerve (acoustic neuromas) that affects hearing can cause significant disabilities.

Putting a Name to the Place

Brain tumors are defined by where they appear. Tumors that arise from the meninges (the membranes that cover the brain) are called meningiomas. Tumors that arise from glial cells (the cells that surround neurons) include astrocytomas, oligodendrogliomas and glioblastoma multiforme (GBM). Grade III meningiomas are also known as malignant meningiomas and are highly aggressive locally.

Removing the Tumor

The best treatment option for all of the tumors mentioned is removing all of the visible tumor. However, in more aggressive tumors, after a safe healing period, radiation is used to try and combat microscopic tumor cells so as to keep recurrence at bay.

Treatment from Other Angles: Alkylating Agents

In the case of GBM, the standard of care utilizes a drug called temozolomide (Temodar) that makes the tumors more sensitive to radiation. Temodar is an alkylating agent and stems from the nitrogen mustards that were used as chemical weapons in World War I. Alkylating agents work by adding an alkyl group to a critical area of the DNA molecule, thereby preventing it from forming a double helix; this causes the DNA in the cancer cells to break, thereby affecting the ability of the cancer cells to multiply.

After radiation with chemotherapy is completed, the patient has a one-month break from treatment. Then, the patient starts chemotherapy cycles, five days per month for twelve months. Every two to three months, the patient receives an MRI of their brain.

The Future of Brain Tumor Treatments

Scientists are making advances with the rapid advancement of genomics and more emerging vaccine treatments and immunological treatments for GBMs. These innovative treatments are being evaluated through safe clinical trials—a necessary step before they become standard treatment. Visit to view our open clinical trials.