Off label drugs for astrocytoma grade 3

We are looking for repurposed drugs for a family member and since most of the research has been done for GBM that is grade 4 tumor I wonder if there is anything to take into account while treating a grade 3 tumor. I once read somewhere, but can't remember where and how reliable this source was, to be careful with cytotoxic drugs for lower stage cancer as they may cause the tumor to develop to a higher grade. Could you let me know what are your opinions on this? What type of drugs would you chose or have you chosen for lower grade tumors? Thank you.