MN wife, really sorry you had to find your way to this forum, but it's a great place to get knowledge and support.
I'm going to leave it to the more knowledgeable guys here to get into specifics, but I'll just say that this is NOT a hopeless situation by any stretch. Is it serious? Sure. But highly treatable. Prostate Cancer is slower growing than other cancers, with many many treatment options and many more in the pipeline. There are many men here with GLeason 8 and 9, more serious than g7 (4+3) , that have survived and thrived, with treatment,
And you are in a great place at Mayo.
Many of the big Cancer centers have "Nomograms" on their website, they are like calculators where you put in your information and based on their database of thousands of men treated with your specific numbers, tells you the chance that you will have a biochemical recurrence or die pf PC.
I put your husbands numbers into the MSKCC nomogram, and the numbers should at least give you hope, and I hope make you feel better.
It showed that a man with your hisbands GLeason after surgery, with his stage and seminal vesicle invasion, ECE, but negative margins and lymph nodes, has a 91% chance of NOT dying of Prostate cancer in the next 15 years. 91%.
So Yes. You should hope.
The numbers on his chance of biochemical recurrence are not as good, but keep in mind, that BCR is when the PSA starts to rise after treatment, and most often, it's years before any symptoms show up after BCR. And with proper treatment your husbands chances of hanging around to drive you crazy till age 80 are pretty darn good.
If you want to do the nomogram yourself, go here
www.mskcc.org/nomograms/prostate/post-opStick around here it's a very helpful place