Seriously, if you had a grand mal seizure due to that tumor in your brain, with its arms reaching for your corpus callosum, and it rapidly encroaching upon areas that would soon render it unresectable in that cantaloupe-sized space known as your cranium, you would have surgery STAT. I guarantee you. Call a neurosurgeon and ask them.
"How long should I wait to have my GBM surgically removed?"
afford - the year was 1949: My mother had a brain tumor (non-malignate) at age 42 and had surgery. The odds of survival were 1 in 80. She survived - lived to age 80. IMO most doctors have the best interest of their patients as #1. Only ran into one quack doctor in my experience.