Your husband unfortunately has IDC( intraductal carcinoma ) which is very aggressive feature according to papers and doctors. If you are not in a center of excellence you should find one and go there for second opinion on biopsy findings and proper treatment. Although perineural invasion is not of extreme concern it IS a concern and as you said yourself shows cancer trying to escape the gland. Ask for Decipher BUT be very proactive (as you are already), I would not personally wait for treatment. My husband unfortunately has IDC and cribriform gland formation and I understand your concern and worry < 3.