Brain cancer is relatively rare. About 0.6 percent of people will be diagnosed with a brain or nervous system tumor at some point in their lifetime, making it far less common than cancers of the breast, lung, prostate, or colon. Still, that small percentage translates to a significant number of diagnoses each year, and the picture gets more complex when you factor in both malignant and non-malignant tumors.
Annual Diagnoses in the U.S.
Between 2018 and 2022, roughly 489,718 primary brain and central nervous system tumors were diagnosed in the United States, averaging just under 98,000 per year. The overall rate was about 26 cases per 100,000 people annually.
What surprises many people is that most of these tumors are non-malignant. Of those nearly 490,000 cases over five years, about 361,000 were non-malignant and 129,000 were malignant. That works out to roughly a 3-to-1 ratio. The malignant rate alone is about 6.9 per 100,000 people per year, while the non-malignant rate is about 19.2 per 100,000. Non-malignant tumors can still cause serious symptoms depending on their size and location, but they grow more slowly and don’t invade surrounding tissue the way cancerous tumors do.
Primary Tumors vs. Cancer That Spreads to the Brain
The numbers above only count primary brain tumors, meaning those that originate in the brain or its surrounding membranes. A separate and much larger category is metastatic brain tumors, which start as cancer somewhere else in the body (most often the lungs, breast, skin, colon, or kidneys) and then spread to the brain. Metastatic brain tumors are estimated to be several times more common than primary ones, though exact counts are harder to pin down because they’re typically tracked under the original cancer type rather than as brain cancer.
If you’ve heard that brain tumors are more common than the 0.6 percent lifetime risk suggests, this distinction is likely why. The statistic refers to cancers that begin in the brain, not all tumors that eventually end up there.
The Most Common Types
Not all brain tumors are the same, and the type matters enormously for prognosis and treatment. Among all primary brain tumors (malignant and non-malignant combined), the breakdown looks like this:
- Meningiomas account for about 42.6% of all primary brain tumors and 57.4% of non-malignant ones. These grow in the membranes surrounding the brain and are usually slow-growing. Many are found incidentally on brain scans done for other reasons.
- Gliomas make up about 22.2% of all tumors. This family of tumors grows within the brain tissue itself and ranges from slow-growing, lower-grade types to highly aggressive ones.
- Glioblastoma, the most aggressive form of glioma, represents 13.7% of all brain tumors and a striking 52.2% of all malignant ones. It’s the diagnosis most people think of when they hear “brain cancer,” and it carries the most serious prognosis.
So when people ask how common brain cancer is, it depends partly on what counts. If you include the large number of non-malignant meningiomas, the overall number is higher than most people expect. If you’re asking specifically about aggressive, life-threatening brain cancer, the numbers are considerably smaller.
Brain Tumors in Children
Brain and nervous system tumors are the most common solid tumors in children, even though they’re still rare in absolute terms. The rate is about 2.9 per 100,000 children per year. The types that affect children differ from those in adults. Pilocytic astrocytomas, medulloblastomas, and other malignant gliomas make up the majority of childhood cases. Many childhood brain tumors respond well to treatment, and survival rates for children tend to be higher than for adults with aggressive types like glioblastoma.
Known Risk Factors
One of the frustrating realities of brain cancer is that most cases have no identifiable cause. The list of confirmed risk factors is short.
Ionizing radiation is the most clearly established environmental risk factor, but it accounts for less than 1% of brain and nervous system tumor cases. This includes radiation from previous cancer treatment directed at the head, not everyday exposures like cell phones or power lines (which have not been shown to cause brain cancer in large studies).
Several rare inherited genetic syndromes raise the risk, including neurofibromatosis, tuberous sclerosis complex, Li-Fraumeni syndrome, and Von Hippel-Lindau syndrome. These conditions are uncommon enough that they explain only a small fraction of total cases. For the vast majority of people diagnosed with a brain tumor, there’s no clear genetic or environmental explanation.
Age and sex play a role in who gets diagnosed. Brain tumors overall are slightly more common in men, and the risk of malignant types increases with age, peaking in older adults. Meningiomas, by contrast, are more common in women.
Putting the Numbers in Context
A 0.6% lifetime risk means that roughly 1 in 167 people will receive a brain or nervous system cancer diagnosis. For comparison, the lifetime risk of lung cancer is about 6%, breast cancer about 13% for women, and prostate cancer about 13% for men. Brain cancer sits well below these more common types.
That said, brain tumors punch above their weight in terms of impact. Even non-malignant tumors can cause seizures, headaches, personality changes, and neurological deficits depending on where they grow. And malignant brain tumors, particularly glioblastoma, remain among the most difficult cancers to treat, with five-year survival rates that lag behind most other cancer types. The rarity of brain cancer is one reason it receives less public attention and research funding relative to its severity.