There are roughly 130 different types of brain and central nervous system tumors, all ranging from benign to malignant, and from extremely rare to relatively common. But of those 130 brain tumors, which are the most common?
We asked Dr. Robert Lustig, M.D., Professor of Clinical Radiation Oncology here at Penn, to give us the rundown on the four most common brain tumors: metastatic, meningioma, glioblastoma, and astrocytoma.
4 Common Brain Tumors
The most common brain tumor among adults, metastatic tumors are classified as secondary brain tumors, which means they arise from cancer that formed elsewhere in the body and then spread to the brain. Though exact incidence rates are not known, the American Brain Tumor Association estimates between 200,000 and 300,000 metastatic brain tumors are diagnosed each year. “As we’re doing better in controlling cancer systemically, we’re beginning to see more metastatic tumors,” said Dr. Lustig, who also noted that metastatic tumors most often stem from lung or breast cancer. Larger metastatic tumors will often be surgically resected—meaning removed—while smaller tumors may be treated with a gamma knife, which is a form of radiation therapy that focuses 200 small beams of radiation onto the tumorous area.
These tumors are technically not brain tumors, as they form in the meninges, which are the membranes that line the skull and vertebral canal. But their growth may affect the brain by causing various disabilities such as vision and hearing impairment, memory loss, or even seizures. Incidents of meningioma increase with age, and the tumors grow slowly, so symptoms could develop gradually over time. Dr. Lustig told us that many meningiomas are benign, so doctors may choose to leave asymptomatic cases alone. However, if the tumor starts adversely affecting quality of life, physicians will either surgically remove it or treat it using radiation therapy. The most common early sign of meningioma is chronic headaches, said Dr. Lustig.
Though it’s the third most common of all brain tumors, glioblastoma is the most common primary brain tumor, which means it originates in the brain. It’s also the most lethal. Roughly 15,000 new cases of glioblastoma are diagnosed every year, with average survival rates resting somewhere in the 11- to- 15-month timeframe. In recent years, glioblastoma has made headlines for taking the lives of senators Ted Kennedy and John McCain, as well as Beau Biden, the son of former Vice President Joe Biden. A full range of treatment approaches are often utilized to fight glioblastoma, including surgical resection, radiation therapy, and chemotherapy, said Dr. Lustig. Penn also has a wide array of glioblastoma clinical trials, the most promising of which are the immunotherapy trials. Immunotherapy basically reprograms a patient’s immune system to target and attack cancer cells. This therapy, which is not yet FDA approved, is a source of hope in the oncology field, with Penn’s Dr. Sean Grady, M.D., recently saying, “I’ve been a neurosurgeon for over 30 years, and the immunotherapy that I’ve seen here at Penn is the first time I’ve actually gotten some hope about making a big difference in malignant brain tumors.”
These primary tumors originate in star-shaped cells called astrocytes, which are located in the brain’s cerebrum. The grade of astrocytoma tumors—meaning their level of malignancy and aggressiveness—varies; sometimes they grow slowly (Grade II) and sometimes they come on more aggressively (Grade III). Treatment approaches to astrocytomas always involve surgery, and occasionally involve chemotherapy and radiation therapy, Dr. Lustig told us. Compared with the other tumors on this list, astrocytomas have more positive overall survival rates. For patients aged 20-44, the survival rates for low-grade astrocytomas are around 68%, dropping to 44% for patients aged 45-54, according to the American Cancer Society.
On the whole, persistent headaches are the most common early signs of brain tumors. That being said, headaches are a pretty routine occurrence in daily life. Dr. Lustig said there are several ways to differentiate a normal headache from one that may be associated with a larger problem such as a brain tumor. Some warning signs would be if your headaches increase in frequency and intensity over days and weeks, and if your headaches become so intense that they wake you up when you’re sleeping.
For people with no history of chronic headaches, if you start suddenly getting these headaches, that would be a thing to worry about,” Dr. Lustig said. Of course, “One headache doesn’t mean anything," he assured. It’s that multiple, frequent, continuous headache” that should cause concern.