How many different stages of brain cancer are there?

What tumor type? Different brain tumors have different grading systems. There is not a single grading system that applies to all types of brain tumors.
What brain cancer. Brain cancer is a layman's term. There are primary brain tumors which do not spread outside the brain and the most common type are called glial tumors. Several types and grades exist, but there is no staging scheme as with breast or lung cancers. Cancers spreading from the body to the brain are metastases and make this a stage 4 cancer.