I'm really sorry, waiting for results is so stressful. I'm going to give you some unsolicited advice, spend as much time as you can with your parents and make every minute count. Have all the conversations you want to have, leave nothing unsaid. Don't be obvious about it, but do it.
My dad died of cancer age 74 and my grief was much harder because he wouldnt talk about the fact he would die one day, we never had any deep conversations. So I missed an opportunity to talk with him about some things I wanted to.
My mum died a month ago, in her 80s. Already I feel the grief is going to be easier to handle, as we were so close, I know her mind on every subject. It is like she is still with me.
After my dad died, it really was very hard for my mum (and me, but not the same). But she made a huge effort to rebuild her life, after a few years she relocated nearby to me and made new friends, started new hobbies. She did enjoy the last 6 years with me and her grandchildren, up until her death, despite the shared grief at losing my dad, despite her increasing frailty.
Try not to be too afraid, you can't stop what's coming. The only part of it you can control is how you respond. If it is bad news for your dad and you don't have anyone to share your anxiety with, join group counselling, find a friend in a similar situation.
Best wishes, hoping the best for your dad