Imaging Somatostatin Receptor Activity in Neuroendocrine-differentiated Prostate Cancer

Neuroendocrine-differentiated prostate cancer (NEPC) is a rare pathophysiology. We herein report a patient diagnosed with conventional prostate adenocarcinoma before hormone therapy, which was later diagnosed as NEPC. The nadir of prostate-specific antigen (PSA) was achieved once. However, adenocarcinoma changed to NEPC in recurrence, and the serum progastrin-releasing peptide (Pro-GRP) and neuron-specific enolase (NSE) values increased. A prostate needle biopsy revealed neuroendocrine differentiation. The chemotherapy regimen was changed, and somatostatin receptor scintigraphy (SRS) helped to determine the distribution and features of lesions as well as the effects of therapy. When prostate cancer worsens despite conventional therapy, NEPC should be considered.