Metastatic Prostate Cancer Treatment: Managing Stage IV Disease

What is metastatic prostate cancer?

Metastatic prostate cancer (Stage IV) is prostate cancer that has spread beyond the prostate to other parts of the body. The most common sites are:

• Bones (80-90%): Spine, hips, ribs, skull
• Lymph nodes: Pelvic, para-aortic, supraclavicular
• Visceral organs (less common): Liver, lungs, brain

Metastatic prostate cancer is not curable, but it is treatable. With modern therapies, many men live 5-10+ years after diagnosis.

Hormone-sensitive (mHSPC) treatment

Metastatic hormone-sensitive prostate cancer (mHSPC) is newly diagnosed metastatic disease that still responds to androgen deprivation therapy (ADT).

Standard of care (2026):

• ADT + docetaxel (chemotherapy): For high-volume disease (CHAARTED trial) – improves survival by 13-17 months
• ADT + abiraterone (Zytiga): For all mHSPC (LATITUDE trial) – improves survival
• ADT + enzalutamide (Xtandi): For all mHSPC (ENZAMET trial) – improves survival
• ADT + apalutamide (Erleada): For all mHSPC (TITAN trial) – improves survival
• ADT + darolutamide (Nubeqa): For mHSPC (ARASENS trial) – improves survival

High-volume vs. low-volume disease:

• High-volume: Visceral metastases OR ≥4 bone metastases (1 outside spine/pelvis). Prefer ADT + docetaxel.
• Low-volume: Any other metastatic disease. Prefer ADT + abiraterone or enzalutamide or apalutamide.

Castration-resistant (mCRPC) treatment

Metastatic castration-resistant prostate cancer (mCRPC) is prostate cancer that progresses despite low testosterone (<50 ng/dL).

First-line mCRPC options:

• Abiraterone (Zytiga): If not used in mHSPC – oral, requires prednisone
• Enzalutamide (Xtandi): If not used in mHSPC – oral, no steroids
• Docetaxel (chemotherapy): Especially for symptomatic disease or visceral metastases

Second-line mCRPC options (after docetaxel):

• Cabazitaxel (Jevtana): Chemotherapy for post-docetaxel progression
• Abiraterone or enzalutamide: If not used previously
• Radium-223 (Xofigo): For bone-only metastases, no visceral disease
• PARP inhibitors (olaparib, rucaparib): For HRR mutations (BRCA, ATM, PALB2)

Third-line mCRPC options:

• Lu-177-PSMA (Pluvicto): PSMA-targeted radioligand therapy
• Pembrolizumab (Keytruda): Only for MSI-H/dMMR tumors (rare)

Bone metastases management

Bone metastases cause pain, fractures, and spinal cord compression. Management includes:

Bone-targeting agents (prevent fractures):

• Denosumab (Prolia, Xgeva): 120 mg subcutaneously every 4 weeks – reduces skeletal-related events by 20-30%
• Zoledronic acid (Zometa): 4 mg IV every 4 weeks – similar efficacy
• Calcium + vitamin D: Required with both (to prevent hypocalcaemia)

Pain management:

• NSAIDs (ibuprofen, naproxen) – first-line
• Opioids (morphine, oxycodone) – for moderate-severe pain
• Radiation therapy – for painful isolated lesions
• Radium-223 – for diffuse bone pain

Spinal cord compression (emergency):

• Symptoms: Back pain, leg weakness, numbness, difficulty walking, loss of bladder/bowel control
• Treatment: High-dose dexamethasone + radiation or surgery

PSMA-targeted therapy (Lu-177-PSMA)

Lutetium-177-PSMA (Pluvicto) is a radioligand therapy that delivers radiation directly to PSMA-expressing prostate cancer cells.

Approval:

• FDA-approved for mCRPC after progression on abiraterone/enzalutamide and docetaxel
• Requires PSMA-PET positive disease (PSMA expression)

Regimen:

• 7.4 GBq (200 mCi) IV every 6 weeks for 4-6 cycles

VISION trial results:

• Median overall survival: 15.3 vs. 11.3 months (control)
• Radiographic progression-free survival: 8.7 vs. 3.4 months
• Side effects: Fatigue, dry mouth, nausea, anaemia

Prognosis and survival

Survival for metastatic prostate cancer has improved dramatically with new therapies:

• Pre-2004 (only ADT): Median survival 2-3 years
• 2004-2010 (docetaxel added): Median survival 3-4 years
• 2010-2020 (abiraterone, enzalutamide, cabazitaxel, radium-223): Median survival 4-5 years
• 2020+ (PARP inhibitors, Lu-177-PSMA, combination therapy): Median survival 5-7+ years

Prognostic factors:

• High-volume disease: Shorter survival (3-4 years)
• Low-volume disease: Longer survival (5-7+ years)
• Visceral metastases (liver, lung): Worse prognosis
• BRCA2 mutations: More aggressive but respond to PARP inhibitors

Treatment algorithm by disease state

Newly diagnosed mHSPC:

1. Start ADT (LHRH agonist or antagonist)
2. Add second agent based on disease volume:
   • High-volume: ADT + docetaxel (6 cycles) or ADT + abiraterone/enzalutamide/apalutamide
   • Low-volume: ADT + abiraterone or enzalutamide or apalutamide

Progression to mCRPC (PSA rise despite castrate testosterone):

1. Confirm castrate testosterone (<50 ng/dL)
2. First-line mCRPC:
   • If not previously used: abiraterone or enzalutamide
   • If symptomatic or visceral metastases: docetaxel
3. Second-line mCRPC:
   • After docetaxel: cabazitaxel, abiraterone/enzalutamide (if not used), radium-223 (bone-only)
   • After abiraterone/enzalutamide: docetaxel, cabazitaxel, PARP inhibitor (if HRR mutation)
4. Third-line mCRPC:
   • Lu-177-PSMA (if PSMA-PET positive)
   • Clinical trials

Interactive FAQ – Metastatic prostate cancer treatment

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Disclaimer: This information is for educational purposes. Metastatic prostate cancer treatment is complex and rapidly evolving. Consult a medical oncologist at Vivekananda Hospital.