Urethral Metastasis of Therapy-Induced Neuroendocrine Prostate Cancer Successfully Managed With Chemoradiotherapy: A Case Report.

INTRODUCTION

Urethral metastasis of prostate cancer is exceptionally rare, particularly in castration-resistant disease. Therapy-induced neuroendocrine prostate cancer (t-NEPC) is an aggressive variant with limited treatment options.

CASE PRESENTATION: A 72-year-old man, 14 years after diagnosis of prostate adenocarcinoma treated with androgen deprivation therapy, presented with hematuria and dysuria. Prostate-specific antigen was 2.05 ng/mL and neuron-specific enolase was 28.0 ng/mL. Urethroscopy revealed papillary tumors in the pendulous urethra. Histology showed high-grade adenocarcinoma with a small cell carcinoma component, positive for synaptophysin and prostate-specific antigen. Genomic profiling demonstrated PTEN loss, TP53 mutation, and androgen receptor amplification. Platinum-based chemotherapy with external-beam radiotherapy achieved durable urethral local control despite later distant progression; the patient survived 2 years 10 months.

CONCLUSION

Platinum-based chemoradiotherapy may provide durable local control of urethral metastasis from t-NEPC.