RB1 and p53 are diagnostic markers for treatment-related neuroendocrine prostate cancer: a clinical and pathological analysis of 23 cases.

The synergistic interplay between RB1 deletions and TP53 mutations drives androgen deprivation therapy (ADT) resistance and neuroendocrine transdifferentiation in advanced prostate cancer, culminating in treatment-related neuroendocrine prostate cancer (t-NEPC). This investigation systematically examines the clinicopathological characteristics and immunohistochemical phenotypes of t-NEPC to enhance diagnostic accuracy and prognostic understanding. We conducted a retrospective analysis of 23 t-NEPC cases diagnosed at the First Affiliated Hospital of Zhejiang University School of Medicine (2013-2024). We collected comprehensive clinical data, including patient demographics, treatment history, and serum biomarker profiles. Immunohistochemical evaluation was performed to determine expression patterns of prostate-associated antigens, neuroendocrine markers, and tumor suppressor proteins RB1/p53. The cohort demonstrated a mean age of 70 years at initial prostate cancer diagnosis, with t-NEPC emerging after a median ADT duration of 18 months. Biochemical profiles revealed a characteristic dissociation between suppressed prostate-specific antigen (PSA) levels and elevated neuroendocrine markers alongside other tumor-associated antigens, including carcinoembryonic antigen (CEA). The immunohistochemical signature of lineage transdifferentiation, indicated by the loss of androgen receptor (AR) and the expression of neuroendocrine markers, provides critical diagnostic clues for this aggressive variant. Molecular alterations were prevalent, with RB1 loss detected in 78.26% (18/23) and p53 abnormalities in 82.61% (19/23) cases. Notably, a histologically confirmed t-NEPC case with neuroendocrine marker negativity exhibited RB1/p53 co-alterations, molecularly aligning with most neuroendocrine-positive cases. These findings substantiate that combined RB1/p53 aberrations serve as robust diagnostic indicators for t-NEPC, particularly in tumors exhibiting small cell carcinoma morphology without neuroendocrine marker expression.