Case presentation
Patients’ clinicopathological data are summarized in Table 1. At the time of BAT initiation, all patients had castrate T levels.
Case 1. A 60-year-old man with end-stage renal disease on hemodialysis three times a week with iPSA 40.5ng/ml and prostate biopsy GS 5+5 was found to have prostate cancer bone metastasis and bladder invasion (cT4N0M1b). He was initially treated with MAB (LHRH analog plus Bicalutamide 80mg qd) since June 2014. Two years later he was diagnosed with CRPC (PSA 4ng/ml) and Enzalutamide 80mg was added to LHRH analog in July 2016. Diabetic nephropathy progressed to end-stage renal disease and hemodialysis was started in October 2017. In August 2018 testosterone enanthate 250mg IM was started and repeated every 4 weeks because high Pro-GRP(160pg/ml) suggested neuro-endocrine prostate cancer. Then the patient was re-challenged with bicalutamide which resulted in a drastic PSA decrease to 1.5 ng/ml. PSA continues to stay at low levels for 20 months. LHRH injections and bicalutamide are being continued as well as testosterone enanthate 125mg IM 4 weeks (Fig 1A).
Case 2. A 59-year-old man with iPSA 9.7ng/ml and prostate biopsy GS 4+3 was diagnosed with locally invasive PCa (cT3aN0M0). He underwent radical retropubic prostatectomy (RRP) and then salvage EBRT. As he progressed to CRPC (PSA 8.4 ng/ml) chemical castration was started and then enzalutamide was added to the treatment. Bone metastasis appeared and Radium chloride (223Ra) 6 injections were done followed by EBRT to the left femur (30Gy). Then, resection of the left femur with femoral head prosthesis implantation was performed because of the left leg pain. AS PSA increased (50.2 ng/ml) docetaxel was started and then switched to cabazitaxel. Testosterone enanthate 250mg IM was started in may 2021 resulting in a more than a fourfold decrease in PSA (Fig. 1B).
Case 3.
A 65-year-old man with iPSA 15.7ng/ml and prostate biopsy GS 4+5 without distant metastasis underwent RRP. The pathological diagnosis was pT3bN1 (a single positive right obturator LN). MAB was started right after the operation. Bicalutamide was switched to flutamide and then to estramustine phosphate followed by enzalutamide. PSA increased steadily reaching 0.84ng/ml and pararectal LN metastasis was diagnosed by PET-CT. The metastasis was surgically resected. PSA decreased to 0.03ng/ml. The patient was sequentially treated with enzalutamide, abiraterone, apalutamide, darolutamide, estramustine phosphate, docetaxel, and cabazitaxel. PSA gradually increased to 8.26ng/ml. Testosterone enanthate 250mg IM was started in May 2021 with initial PSA flare to 80.87ng/ml because of liver, retroperitoneal and pelvic lymph node metastasis then drop to17.56ng/ml. The patient is now being treated with monthly T with triweekly injections of gemcitabine and carboplatin (Fig. 1C). CT revealed PR in the liver and LN metastasis (Figure 2).
Case 4.
A 71-year-old man with iPSA 350ng/ml and prostate biopsy GS 4+4. Prostate MRI revealed extracapsular invasion. CT scan revealed enlarged left internal iliac LN, but no distant metastasis. Chemical castration with degarelix injection was performed and MAB was started by adding bicalutamide which was sequentially switched to flutamide, enzalutamide, and abiraterone. Five years since the beginning of the therapy the patient opted for surgical treatment and underwent RRP. The pathological diagnosis was T3bN1 with 5 out of 21 LN had metastasis. Following the operation, ADT was continued using enzalutamide. PSA increased and salvage EBRT (70Gy) was done. A whole-body MRI revealed multiple spine bone metastasis and multiple LN metastasis. BMA denosumab was started. Enzalutamide was switched to estramustine followed by darolutamide. PSA increased to 66 ng/ml. Testosterone enanthate 250mg IM was started in may 2021 followed by a drastic decrease in PSA (Fig. 1D).