Metastasized Prostate Cancer

My husband had prostatectomy surgery with 2 lymph nodes removed in October 2018.  The margins and frozen sections were clear and subsequent PSA tests are undetectable.  He recently went for routine eye exam and a lesion was noticed in eye, but he had no symptoms of any kind.  After MRI of brain, there were numerous areas of enhancement in brain.  Then an occular oncologist was called in and a team of doctors ordered many tests mainly to determine if this was from the original prostate cancer.  Bone scans were clear, and the thought was this was not from prostate.  His PSA was still undetectable.  After further tests (Ct scan, PET scan) areas of lesions were found in lymph nodes, liver and lung.  After biopsy of liver, there was evidence of prostate cells, and the diagnosis is large cell neuro-endocrine carcinoma.  Apparently the prostate cancer spread through the nerve system which is quite unusual.  Anyone out there with advice or know of cases like this?  We are in Houston so have a great team of oncologists.  I know the doctors will treat this aggressively, but this is a complicated case.   Appreciate any input, or support.