Following up: Jobs had a much less aggressive form of pancreatic cancer. He refused/delayed surgery to remove the tumor for *9 months* while trying alternative medicine. Even after the surgery, he lived 7 more years. There was no real reason he couldn't have explored alt medicine *in addition* to conventional medicine and treatment, and there's a lot of reason to say he would've lived much longer. Can I say that definitely? No, but nobody can say anything definitively. There's enough evidence here to say he fell for the same mix of woohoo spirituality that drives a lot of other people to make bad decisions.
This piece is much kinder to Steve Jobs than I was, but of course it's not considering his choices in light of his overall life (that makes sense, because that's not the job of medical science): https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4924574/
I'm sorry about your father. It sounds like he had the more aggressive form of cancer.