Hi Alamal, and a warm welcome to the forum, though I'm sorry you have to be here, I too have prostate cancer. Stage 3, locally advanced prostate cancer, means the tumour has broken the shell, "outer skin," of the prostate, but It does not mean it has reached anywhere else yet, and the 0.4 mm lesion/tumour size, is a hopeful indicator it hasn't as well, though being stage 3 often means the cancer can have aggressive characteristics and needs to be treated soon, I can understand how awful you are feeling right now, we've all been through it and know it's not a nice place to be, but as long as the cancer is localised, his outlook is very good with a near 100% survival rate. there are a few good treatments for your husband, but not knowing his details, I cant say which one, the most common are,

Removal of the prostate, sometimes followed with radiotherapy.

hormone therapy with a course of radiotherapy part way through

chemotherapy sometimes with hormone therapy,

triple therapy, a combination of hormone therapy, radiotherapy and chemotherapy.

best wishes to you both

Eddie