Can Snake Bite Cause Malignant Brain Tumor?

My husband was bitten by a Diamond-Back rattle snake August 2005. He was given 18 viles of anti venom and his life was saved. One year and 4 months later he was diagnosed with Astrocytoma, Glioblastoma grade IV. The doctor removed the tumor and he lived for 3.5 more years and recently passed in July. My question is, could the snake bite have caused the malignant brain tumor? At age 57, he was otherwise in perfect health with no immediate family having cancer.
Thank you,
Harriet