Can someone survive if they have brain cancer (gbm)?

Very rare: If it is a GBM (glioblastoma multiforme) this a high grade malignant tumor of the brain with poor prognosis. Even with resection and chemo/radiation, these tumors recur and survival is generally less than a couple of years. There are rare subtypes of GBM that may have longer survival (giant cell variant) up to 5 years, but this is extremely rare. Make sure the diagnosis is correct.