Bipolar androgen therapy for treatment of metastatic castration-resistant prostate cancer: A case series

Advanced prostate cancer treatment has improved with androgen receptor signaling inhibitors (ARPI), yet many patients develop metastatic castration-resistant prostate cancer (mCRPC), characterized by sustained androgen receptor (AR) signaling. Bipolar androgen therapy (BAT) introduces supraphysiologic testosterone levels to inhibit tumor growth, offering novel treatment for mCRPC by exploiting AR-dependent mechanisms.

Case 1: A 53-year-old man with mCRPC, post multiple systemic therapies, initiated BAT and pembrolizumab, achieving PSA reduction and improved quality of life before progression. The patient exhibited AR amplification, which may have contributed to favorable response to BAT. Case 2: A 73-year-old man with recurrent prostate cancer, stable on ADT and abiraterone, experienced PSA decline with BAT to an undetectable level, maintaining stability post-therapy discontinuation. Case 3: A 73-year-old man with metastatic prostate cancer, initially resistant to enzalutamide, achieved clinical benefit and disease control with BAT, although he did not meet PSA response criteria, patient had remarkable response upon enzalutamide rechallenge. Case 4: A 90-year-old man with localized prostate cancer, refractory to multiple treatments, experienced symptom relief and PSA reduction with BAT before progression.

BAT represents a promising treatment strategy for mCRPC. This case series underscores BAT's potential to induce significant clinical and biochemical responses, resensitize tumors to ARPIs, and improve patients' quality of life. Despite eventual progression in some cases, BAT offers a period of disease control. Further research is needed to optimize patient selection and understand the molecular determinants of BAT responsiveness.