Brain metastases
Cancer that started somewhere else in the body and spread to the brain.
What brain metastases are
These are tumors in the brain that did not start there. Cancer cells travelled from somewhere else in the body and settled in the brain.
You may hear them called brain mets, or secondary brain tumors.
Why the starting point matters
A brain metastasis is still made of the first cancer. Lung cancer that spreads to the brain is treated as lung cancer in the brain, not as a brain tumor that started there.
That is why your team keeps naming the first cancer, and why treatment often follows what works for that cancer.
There can be one, or several in different places. Your team counts them and notes where they are, because that shapes the plan.
What to ask your team
- Where did this cancer start?
- How many are there, and where?
- Does my treatment need to reach the brain specifically?
This is not medical advice. It explains research in plain words. Your care team knows your case. Talk with them before you make any decision about your treatment.