Hi Pat, it is confusing at your stage, but you have very few facts at the moment, and you need to be patient. It's not easy, I know, but searching for clues as to what "might" be the case will probably make you draw all the negative conclusions.
The situation will come clear only after Allan has had his MRI scan, and then biopsies, if that's what the scan calls for. Only then will the consultant give you the low down, and the proposed treatment, and why.,
There are dozens of "what if's", digging them out will only serve to worry and panic.
But don't forget, his PSA is very low, he doesn't have any symptoms, and doesn't even know if he has cancer.
He's pretty much in the same situation as I was some months ago. I only ever considered facts which were proven, and Im pleased to say I kept a lid on the worry and panic.
My radiotherapy ended about a month ago, and Im pretty confident I've been cured.
Good luck to you both, please keep positive.