How does brain cancer affect the brain?

It depends. This is a difficult question to answer because it really depends on where the cancer is in the brain and how extensive it is. Different parts of the brain are responsible for different things. So for example it is possible that a brain cancer could impact someone's speech for one person but not another.
Dysfunction. Since brain cancer/tumor originates in the brain, it will create dysfunction in the brain. What kind of function is impaired is dependent on the location of the tumor in the brain. Sometimes it's memory, sometimes weakness, sometimes blindness, and many many more.

Related Questions

How does having brain cancer affect the brain function?

Location. This is entirely dependent on the location of the tumor. There will be certain dysfunction by the affected area of the brain where the tumor is. It also is dependent on the side of the brain where the tumor is. Read more...

What do you suggest if my girlfriend has stage 3 brain cancer and I don't know what to do :' (?

Brain tumor. The first step is to get established with a neuro-oncologist who takes care of people with grade III Astrocytomas (anaplastic type). Today there are good chemotherapy regimens that are very effective. Radiation therapy is also an adjunct to chemotherapy. Brain surgery is performed if reduction in the size of the tumor is required. Your role is to be supportive, reassuring, and keep her organized. Read more...