My Husband Was Dx With GBM Las Oct 2015, Had

My husband was dx with GBM las oct 2015, had tumor removed next week, then 6 weeks of radiation, then 6 mo of temador. He also wore Novacure head gear for 6 mo. He fell in aug. and broke his hip. He has not had any treatments since July 2016. Dr wanted to start on Avastin but my husband declined and wants no further treatments. He uses a walker to ambulate and is having difficulty holding his urine and bowels at times. He doesnt sleep much and has left sided weakness. what is the timeline for death after treatments have stopped. The tumor has returned per his oncologist.