ABSTRACT Introduction Neuroendocrine prostate cancer is a rare and highly aggressive variant of prostate cancer with a poor prognosis. We report a case in which metastatic castration‐sensitive prostate cancer directly transformed into neuroendocrine prostate cancer without a corresponding increase in prostate‐specific antigen. Case Presentation An 86‐year‐old male with severe acute renal failure demonstrated a prostate‐specific antigen level of 306 ng/mL and a Gleason score of 4 + 5 on prostate biopsy. Imaging revealed lung, bone, and lymph node metastases, leading to a diagnosis of high‐risk metastatic castration‐sensitive prostate cancer. Abiraterone acetate was initiated immediately. Nineteen months later, multiple liver metastases were detected despite stable prostate‐specific antigen levels. The patient died 4 months later. Autopsy revealed widespread metastases, all histologically confirmed as neuroendocrine prostate cancer. Conclusion Strong androgen receptor suppression in metastatic castration‐sensitive prostate cancer can lead to aggressive radiographic progression without prostate‐specific antigen elevation, underscoring the limitations of antigen‐based monitoring.
Nakagami et al. (Wed,) studied this question.