Hi Commonside. Welcome to the forum.

I'm sorry to hear of your husband's diagnosis. I was equally devastated in 2010 when I was diagnosed.  My own cancer was caught in time and I had a radical prostatectomy.  My own PSA was also 5.6 but my Gleason was 7 (3+4). 

Given that 5.6 isn't very high, is there any indication of how advanced his cancer is, and whether it might be curable with radiotherapy or surgery once the tumour has been shrunk by the hormone therapy?  I had a colleague who also had locally advanced cancer which was successfully treated with surgery and then follow up radiotherapy. 

There are a few of us here with prostate cancer, but you might like to know that there are two specialist prostate cancer forums run by Macmillan and Prostate Cancer UK.  I do recommend you join one or both of those forums, too.