Management of Metastatic Hormone‑Naïve and Castration‑Resistant Prostate Cancer

Initial Hormone‑Naïve Metastatic Disease

ADT Strategies

• Continuous androgen‑deprivation therapy (ADT) is the cornerstone first‑line treatment for metastatic prostate cancer; in patients fit for chemotherapy, adding docetaxel to ADT significantly improves overall survival and is the preferred initial approach. [Annals of Oncology] 1
• Bilateral orchiectomy or luteinizing‑hormone‑releasing hormone (LHRH) agonists are the recommended methods for achieving castration‑level testosterone. [Journal of Clinical Oncology] 2
• When initiating an LHRH agonist, a short course (3–4 weeks) of anti‑androgen therapy is required to prevent a testosterone flare that could temporarily worsen disease. [Annals of Oncology] 3
• LHRH antagonists can be used as initial ADT because they avoid the testosterone flare associated with agonists. [Annals of Oncology] 1

Combination Therapy Considerations

• In patients with good performance status and metastatic hormone‑naïve disease, ADT combined with docetaxel 75 mg/m² every 3 weeks provides superior overall survival compared with ADT alone. [Annals of Oncology] 1
• Adding an anti‑androgen to castration (combined androgen blockade) does not confer a clinically relevant survival advantage and is not recommended for routine use. [Annals of Oncology] 1
• Intermittent ADT is not recommended for metastatic disease outside clinical trials because it failed to demonstrate non‑inferiority for survival. [Annals of Oncology] 4

Bone‑Targeted and Additional Chemotherapy (What Not to Do Initially)

• Initiating bone‑targeting agents (denosumab or bisphosphonates) at the time of diagnosis of metastatic hormone‑naïve disease is not recommended. [Annals of Oncology] 1
• Cytotoxic chemotherapy beyond docetaxel should be reserved for clinical‑trial settings and not used routinely at initial presentation. [Annals of Oncology] 3
• Anti‑androgen monotherapy is inferior to surgical or medical castration and should be avoided. [Annals of Oncology] 1

Castration‑Resistant Prostate Cancer (CRPC)

First‑Line Chemotherapy

• Docetaxel 75 mg/m² every 3 weeks together with prednisone remains the standard first‑line chemotherapy for metastatic CRPC, having demonstrated an overall‑survival benefit in phase III trials. [Annals of Oncology; NCCN] 5
• Docetaxel may be deferred in truly asymptomatic patients, but should be strongly considered when there is a rapid PSA rise, visceral metastases, or anaplastic tumor features. [Annals of Oncology] 1
• ADT should be continued throughout CRPC treatment to maintain castrate testosterone levels. [Annals of Oncology] 1

Post‑Docetaxel Options (Level I Evidence)

• For patients with good performance status who progress after docetaxel, the following agents have Level I evidence for survival benefit: cabazitaxel, abiraterone, enzalutamide, and radium‑223. [Annals of Oncology; NCCN] 6

Bone‑Directed Therapy in CRPC

• In CRPC patients with bone metastases at high risk for skeletal‑related events, initiate denosumab or zoledronic acid; denosumab provides a superior delay in such events. [NCCN] 6
• Zoledronic acid administered every 3–4 weeks carries Category 1 evidence for preventing pathologic fractures, spinal‑cord compression, and the need for bone surgery or radiation. [NCCN] 5

Monitoring and Surveillance

• Perform regular clinical assessment and serum PSA measurement to track disease activity. [Annals of Oncology] 1
• Baseline staging with a bone scan plus CT or MRI of the abdomen and pelvis is strongly recommended at diagnosis. [Annals of Oncology] 1
• Routine systematic imaging surveillance is not required in the absence of a PSA rise or cancer‑related symptoms. [Annals of Oncology] 1

Neuroendocrine Differentiation and Special Situations

• PSA is unreliable in patients with undifferentiated or anaplastic metastatic prostate cancer that exhibits neuroendocrine features. [Annals of Oncology] 1
• Patients with Gleason grade 9–10 or those not responding adequately to ADT should undergo biopsy of an accessible lesion to assess for neuroendocrine differentiation. [NCCN] 5
• When neuroendocrine differentiation is identified, add platinum‑based chemotherapy (cisplatin + etoposide or carboplatin + etoposide) to ongoing ADT. [NCCN] 5
• These neuroendocrine‑type tumors often present with visceral metastases and disproportionately low PSA relative to disease burden. [Annals of Oncology] 1

Treatment Options for Prostate Cancer Metastasis

First-Line Treatment for Metastatic Prostate Cancer

• The European Society for Medical Oncology recommends continuous androgen deprivation therapy (ADT) as the standard first-line treatment for metastatic hormone-naïve prostate cancer, with the addition of docetaxel chemotherapy for patients fit enough to receive it 7, 8
• When starting treatment with an LHRH agonist, an antiandrogen should be given for 3-4 weeks to prevent testosterone flare, as recommended by the European Society for Medical Oncology 9
• ADT plus docetaxel is recommended as first-line treatment for metastatic hormone-naïve disease in men fit enough for chemotherapy, according to the European Society for Medical Oncology 7, 8
• Regular exercise should be recommended for men starting ADT as it reduces fatigue and improves quality of life, as suggested by the European Society for Medical Oncology 7, 8

Intermittent vs. Continuous ADT

• Intermittent ADT is not recommended for metastatic hormone-naïve prostate cancer outside of clinical trials, unless there is significant intolerance to hormone therapy, as stated by the European Society for Medical Oncology 9

Treatment of Castration-Resistant Prostate Cancer (CRPC)

• Abiraterone or enzalutamide are recommended for asymptomatic/mildly symptomatic men with chemotherapy-naïve metastatic CRPC, according to the European Society for Medical Oncology 7, 8
• Docetaxel is recommended for men with metastatic CRPC, as suggested by the European Society for Medical Oncology 7, 8
• Radium-223 is recommended for men with bone-predominant, symptomatic metastatic CRPC without visceral metastases, as recommended by the European Society for Medical Oncology 7, 8

Supportive Care for Bone Metastases

• A single fraction of external beam radiotherapy is recommended for palliation of painful bone metastases, according to the European Society for Medical Oncology 7
• In patients with bone metastases from CRPC at high risk for clinically significant skeletal-related events, denosumab or zoledronic acid can be recommended, as suggested by the European Society for Medical Oncology 7
• MRI of the spine to detect subclinical cord compression is recommended in men with CRPC with vertebral metastases, as recommended by the European Society for Medical Oncology 7

Monitoring During Treatment

• Patients receiving ADT should be monitored with clinical assessment and PSA measurement, as well as management of side effects, according to the European Society for Medical Oncology 9
• Initial imaging by bone scan and CT scan (or MRI) of the abdomen and pelvis is strongly recommended, though systematic imaging surveillance is not mandatory in the absence of PSA rise or cancer-related symptoms, as stated by the European Society for Medical Oncology 9
• Men on long-term ADT should be monitored for side-effects including osteoporosis (using bone densitometry) and metabolic syndrome, as suggested by the European Society for Medical Oncology 7

Important Considerations and Caveats

• PSA is not always a reliable indicator of disease activity in the rare population of patients with undifferentiated (or anaplastic) metastatic prostate cancer with neuroendocrine features, as noted by the European Society for Medical Oncology 9
• Patients with evidence of neuro-endocrine change in their prostate cancer should receive chemotherapy in addition to ADT, according to the European Society for Medical Oncology 7