Dana,
Don't mess with the statistics. As of this point, with some lymph node involvement and prostate involvement, it means T4. Many have local spread to lymph nodes and are successfully treated with chemo.
CT/PET scan is one test for looking for any distant spread but that will be up to his doctor. There are other things, and no, it is not by biopsies.
I'd say it may be a good time to stop searching the internet.
Go with the assumption that he does not have mets if mets have not been found. Get the chemo and continue to get the scans to see if it shows up anywhere else. Hopefully, it will not.
Declare a part of your house to be a "Cancer free" zone. Either that or maybe declare a certain time of the day as a "cancer free" time. Kind of a time out from cancer. During that time out, there is to be no thinking of or talking about cancer. It's a put it all on hold, break from cancer. It can get all to overwhelming and consuming so both you and your husband need a time or place where you put it away and do and think about other things.
Stress is bad for everybody and it is not denial to "take a break" from it all now and then.
Not sure if you've seen posts from Jimswife (Carla). Her husband Jim had lymph involvement and chemo and he's doing well now.
Mike
Age 54
10/31/06 dx CIS (TisG3) non-invasive (at 47)
9/19/08 TURB/TUIP dx Invasive T2G3
10/8/08 RC neobladder(at 49)
2/15/13 T4G3N3M1 distant metastases(at 53)
9/2013 finished chemo -cancer free again
1/2014 ct scan results....distant mets
2/2014 ct result...spread to liver, kidneys, and lymph...