prostate%20cancer
PROSTATE CANCER

Prostate cancer is the cancer that occurs in the male's prostate.

It is the most common cancer in men >50 years of age.

Signs and symptoms include weak urinary stream, polyuria, nocturia, hematuria, erectile dysfunction, pelvic pain, back pain, chest pain, lower extremity weakness or numbness and loss of bowel or bladder control.

Prostate%20cancer Treatment

Androgen Deprivation Therapy (ADT)

  • Treatment option for patients with disease progression despite surgical treatments and radiotherapy, or for symptomatic control of symptoms in patients who are against, with contraindications, or cannot tolerate surgical procedures
  • Recommended as first-line therapy in high- to very high-risk and metastatic prostate cancer and as adjuvant therapy for patients with low- to intermediate-risk prostate cancer
  • May be offered to intermediate- to high-risk and locally advanced prostate cancer patients prior to, during, or after external beam radiation therapy (EBRT) or in combination with radical radiotherapy
    • Long-term ADT (18-36 months duration) is recommended for high-risk to very high-risk disease
    • Short-term ADT (4-6 months duration) is recommended for intermediate-risk disease
  • Treatment option for patients with disease progression after observation who require treatment or with life expectancy of ≤5 years
  • PSA levels should be measured every 3 months for patients under intermittent ADT
    • Restart ADT if PSA measurements reach >10 ng/mL or if patients becomes symptomatic

Treatment Strategies for ADT

  • Luteinizing hormone-releasing hormone (LHRH) analogs (medical castration) and bilateral orchiectomy (surgical castration) are equally effective

Recommended ADT Options for Clinically Localized Prostate Cancer

  • LHRH agonist monotherapy
  • LHRH agonist with 1st-generation anti-androgen
  • LHRH antagonist

Recommended ADT Options for Regional Prostate Cancer

  • Orchiectomy with or without Abiraterone 
  • LHRH agonist monotherapy
  • LHRH agonist with 1st-generation anti-androgen or Abiraterone
  • LHRH antagonist with or without Abiraterone

Recommended ADT Options for Castration-naive Prostate Cancer without Metastasis

  • If with PSA persistence or recurrence after radical prostatectomy: EBRT with or without neoadjuvant/concurrent and/or adjuvant ADT
  • If with PSA persistence or recurrence after EBRT, TRUS-biopsy negative, or with disease progression after salvage EBRT: 
    • Orchiectomy 
    • LHRH agonist monotherapy
    • LHRH agonist with 1st-generation anti-androgen
    • LHRH antagonist

Recommended ADT Options for Metastatic Castration-naive Prostate Cancer

  • Orchiectomy with or without Docetaxel
  • Orchiectomy with Abiraterone, Apalutamide or Enzalutamide
  • LHRH agonist monotherapy with or without Docetaxel
  • LHRH agonist with 1st-generation anti-androgen with or without Docetaxel
  • LHRH antagonist with or without Docetaxel
  • LHRH antagonist with Abiraterone, Apalutamide or Enzalutamide

Orchiectomy

  • Also called surgical castration, total or subcapsular pulpectomy, where one or both testicles (bilateral orchiectomy) are removed
  • Surgical option of ADT, to be done w/ or without Abiraterone therapy
  • Recommended castration method for patients with intermediate- to very high-risk prostate cancer and those with treatment-naive locally advanced and metastatic prostate cancer

Luteinizing Hormone-Releasing Hormone (LHRH) Analogs

  • Efficacy for castration is the same as orchiectomy
  • First-line agents used for ADT in prostate cancer

LHRH Agonists

  • Eg Goserelin, Histrelin, Leuprorelin (Leuprolide), Triptorelin
  • Mechanism of action: Stimulates luteinizing hormone-releasing hormone receptors, inducing a transient leutenizing hormone (LH) and follicle-stimulating hormone (FSH) surge, leading to androgen release inhibition
  • Induces the flare-up phenomenon, a sudden increase in testosterone, which may lead to increased bone pain, urethral obstruction, renal failure, spinal cord compression
  • Efficacy of Leuprorelin may be affected by handling errors during preparation and administration
    • Based on the recommendation by the Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency (EMA), Leuprorelin-containing depot medicinal products using dual-chamber prefilled syringe device are preferred over vial-ampoule presentation, due to fewer reported medication errors with dual devices compared to products with complex reconstitution steps for preparation and administration

LHRH Antagonist

  • Eg Degarelix
  • Mechanism of action: Rapidly and directly inhibits androgen release thereby suppressing testicular androgen activity without the flare-up phenomenon

Secondary Hormone Therapy

  • Second-generation anti-androgens, eg Abiraterone acetate, Apalutamide, Darolutamide, Enzalutamide given in combination with ADT for patients with castration-sensitive prostate cancer or as monotherapy in CRPC
  • Recommended for patients with progressive disease despite medical and surgical castration

Abiraterone acetate

  • May be used for patients with metastatic, high-risk, castration-sensitive prostate cancer together with LHRH analogs or orchiectomy, and metastatic CRPC pre- or post-Docetaxel therapy
  • Administered together with Prednisone; fine-particle Abiraterone is given with Methylprednisolone
    • Combination should not be given with anti-androgen
  • Increased median survival, provided pain palliation, showed PSA level decrease, and delayed radiographic progression in studies done to prove the efficacy of Abiraterone in patients with metastatic CRPC who were given Docetaxel-containing regimens
  • Studies showed that addition of Abiraterone to ADT in patients with high-risk metastatic prostate cancer improved overall survival compared with ADT alone
  • Mechanism of action: Inhibits the enzyme CYP17 in turn suppressing testosterone production

Apalutamide

  • Treatment option for patients with non-metastatic CRPC if PSADT is ≤10 months and metastatic, castration-sensitive prostate cancer
  • Mechanism of action: Acts as an androgen receptor inhibitor thereby inhibiting AR nuclear translocation, DNA binding and androgen receptor-mediated transcription

Darolutamide

  • Treatment option for patients with non-metastatic CRPC if PSADT is ≤10 months
  • Mechanism of action: Competitively inhibits androgen binding to androgen receptors thereby inhibiting nuclear translocation and DNA interaction

Enzalutamide

  • May be used for patients with both metastatic and non-metastatic CRPC if PSADT is ≤10 months and metastatic, castration-sensitive prostate cancer
    • Treatment option for patients with metastatic CRPC pre- or post-Docetaxel
    • Compared with placebo, treatment with Enzalutamide showed significant lower risk of metastasis or death in patients with non-metastatic CRPC with a rapidly increasing level of PSA
  • Mechanism of action: Potent competitive inhibitor of androgen binding to androgen receptors, inhibits nuclear translocation of activated receptors and the association of the activated androgen receptor with DNA despite androgen receptor over-expression and prostate cancer cell resistance to anti-androgens

Other Secondary Hormone Therapy
Adrenal/Paracrine Androgen Synthesis Inhibitors

  • Eg Ketoconazole
  • Treatment option for patients with castration-resistant prostate cancer (CRPC) with or without visceral metastases
  • Mechanism of action: Anti-androgenic properties that block androgen production

Anti-Androgen Therapy

  • Eg Steroidal (Cyproterone acetate, Megestrol acetate, Medroxyprogesterone acetate); Non-steroidal or 1st-generation anti-androgens (Bicalutamide, Flutamide, Nilutamide)
  • Treatment option for patients with advanced disease, metastatic, or non-metastatic CRPC
    • May be given concomitantly with luteinizing hormone-releasing hormone (LHRH) analogs or orchiectomy for better androgen blockade (combined androgen blockade)
    • May be offered to patients with metastatic disease who prefer their sexual function restored even with more side effects
  • Mechanism of action: Blocks androgen receptors, thereby reducing the effect of endogenous hormones
  • Bicalutamide monotherapy may also help prevent non-metastatic bone fractures with its bone-protective properties, though monotherapy use is rare

Estrogens

  • Eg Diethylstilbestrol (DES)
  • Mechanism of action: Inactivates androgens, down-regulates LHRH secretion, Leydig cell function direct suppression
  • Studies have shown that oral estrogen therapy has the same efficacy for castration as bilateral orchiectomy

Docetaxel

  • Systemic treatment added to ADT for patients with metastatic, castration-sensitive prostate cancer
  • Studies showed that addition of Docetaxel to ADT in patients with metastasis significantly improved overall survival compared with ADT alone
  • Mechanism of action: Promotes the assembly of microtubules from tubulin dimers, and inhibits the depolymerization of tubulin which stabilizes microtubules in the cell, resulting in inhibition of DNA, RNA, and protein synthesis

Systemic Therapy

Chemotherapy

  • Eg Cabazitaxel, Carboplatin, Docetaxel, Doxorubicin, Etoposide, Estramustine, Mitoxantrone, Paclitaxel, Vinblastine, Vinorelbine
  • Recommended for patients with progressive disease despite medical and surgical castration (both hormone-resistant and/or castration-resistant metastatic prostate cancer)

Cabazitaxel

  • Alternative treatment to those intolerant or unresponsive to Docetaxel therapy
  • Patients given Cabazitaxel exhibited improvement in progression-free survival (PFS), PSA response rate and overall survival in several studies
  • Given with concomitant steroids (daily Prednisone or Dexamethasone on day of chemotherapy)

Docetaxel

  • Recommended 1st-line treatment for men with symptomatic metastatic CRPC
  • Proven to improve PSA response and time to recurrence and clinical progression
  • Should be reserved for prostate cancer patients with confirmed metastatic disease

Mitoxantrone

  • May be used for palliative therapy of the pain caused by bone metastasis of CRPC
  • Given concomitantly with corticosteroids

Olaparib

  • A poly-ADP ribose polymerase (PARP) inhibitor used as a treatment option for patients with mCRPC and a pathogenic mutation (germline and/or somatic) in a homologous recombination repair (HRRm) gene (BRCA1, BRCA2, ATM, BARD1, BRIP1, CDK12, CHEK1, CHEK2, FANCL, PALB2, RAD51B, RAD51C, RAD51D or RAD54L), with history of androgen receptor-directed therapy

Rucaparib

  • A PARP inhibitor used as a treatment option for patients with mCRPC and a pathogenic BRCA1 or BRCA2 mutation (germline and/or somatic) with history of androgen receptor-directed therapy and a taxane-based chemotherapy

Immunotherapy

Atezolizumab

  • A humanised immunoglobulin G1 monoclonal antibody given with Carboplatin and Etoposide for 1st- and subsequent-line treatment of small cell/neuroendocrine prostate cancer

Pembrolizumab

  • Anti-PD1 antibody used for patients with unresectable or metastatic microsatellite instability-high (MSI-H) or mismatch repair (MMR)-deficient solid tumors that have progressed on prior treatment and with no satisfactory alternative treatment options

Sipuleucel-T

  • Cancer vaccine produced from the combination of autologous antigen-presenting blood mononuclear cells and recombinant human fusion protein
  • Studies have shown that Sipuleucel-T may help extend mean survival with reduction in mortality risk
  • May be given to metastatic CRPC patients with Eastern Cooperative Oncology Group (ECOG) performance status of 0-1, life expectancy of >6 months, absent hepatic metastases, and minimal or absent symptoms

Recommended Therapy for Castration-Resistant Prostate Cancer (CRPC)

  • For CRPC patients without metastasis, may continue ADT and start Apalutamide or other secondary hormone therapy if PSADT ≤10 months

Regimens for Metastatic CRPC if without Visceral Metastasis

  • Abiraterone acetate with Prednisone
  • Docetaxel
  • Plus radiotherapy with Radium-223 if with bone metastasis
  • Other secondary hormone therapy
    • First-generation anti-androgens: Bicalutamide, Flutamide, Nilutamide
    • Anti-androgen withdrawal
    • Ketoconazole +/- Hydrocortisone
    • Corticosteroids: Dexamethasone, Hydrocortisone, Prednisone
    • DES or other estrogens
  • Recommended subsequent therapies include Docetaxel (if previously given Enzalutamide or Abiraterone), Radium-223 (if with bone metastasis), Pembrolizumab (MSI-H or dMMR), Enzalutamide (if not previously given), Abiraterone acetate with Prednisone (if not previously given), Sipuleucel-T (if not given previously), Cabazitaxel or Mitoxantrone with Prednisone (if previously given Docetaxel), and other secondary hormone therapy
    • May propose a Docetaxel rechallenge in patients who responded to previous Docetaxel regimen
  • If with disease progression, may initiate therapy with agents not previously given

Regimens for Metastatic CRPC if with Visceral Metastasis

  • Recommended subsequent combination regimens for patients with small cell CRPC include Cisplatin/Etoposide, Carboplatin/Etoposide, and Docetaxel/Carboplatin
  • Recommended 1st-line therapies for CRPC patients with adenocarcinoma include Docetaxel, Enzalutamide, Abiraterone with Prednisone, Mitoxantrone with Prednisone, and other secondary hormone therapy
    • If with disease progression, Docetaxel, Pembrolizumab (MSI-H or dMMR), Enzalutamide (if not previously given), Abiraterone acetate with Prednisone (if not previously given), Cabazitaxel or Mitoxantrone with Prednisone (if previously given Docetaxel) and other secondary hormone therapy may be considered

Treatment Strategy for Adenocarcinoma-type Metastatic Castration-Resistant Prostate Cancer

First-line Treatment Regimens

  • Preferred treatment options include Abiraterone, Docetaxel, Enzalutamide and Sipuleucel-T
  • Regimens that can be used depending on patient's status include:
    • Symptomatic bone metastases: Radium-223
    • Symptomatic patients with visceral metastases intolerant to other therapies: Mitoxantrone
  • Other recommended therapies include fine-particle Abiraterone and other secondary hormone therapy
Second-line Treatment Regimens
Recommended Options for Patients Given Abiraterone or Enzalutamide as 1st-line Therapy
  • Preferred treatment options include Docetaxel and Sipuleucel-T
  • Regimens that can be used depending on patient's status include:
    • BRCA mutation-positive: Rucaparib
    • HRRm positive: Olaparib
    • MSI-H or dMMR positive: Pembrolizumab
    • Symptomatic bone metastases: Radium-223
  • Other recommended therapies include Abiraterone, Cabazitaxel, Enzalutamide, fine-particle Abiraterone and other secondary hormone therapy
Recommended Options for Patients Given Docetaxel as 1st-line Therapy
  • Preferred regimens include Abiraterone, Cabazitaxel and Enzalutamide
  • Regimens that can be used depending on patient's status include:
    • BRCA mutation-positive: Rucaparib
    • HRRm positive: Olaparib
    • MSI-H or dMMR positive: Pembrolizumab
    • Symptomatic bone metastases: Radium-223
    • Symptomatic patients with visceral metastases intolerant to other therapies: Mitoxantrone
  • Other recommended therapies include fine-particle Abiraterone, Sipuleucel-T and other secondary hormone therapy
    • Treatment rechallenge with Docetaxel may be considered

Subsequent Treatment Options

  • Preferred treatment options include Abiraterone, Cabazitaxel, Docetaxel rechallenge and Enzalutamide
  • Regimens that can be used depending on patient's status include:
    • BRCA mutation-positive: Rucaparib
    • HRRm positive: Olaparib
    • MSI-H or dMMR positive: Pembrolizumab
    • Symptomatic bone metastases: Radium-223
    • Symptomatic patients with visceral metastases intolerant to other therapies: Mitoxantrone
  • Other recommended therapies include fine-particle Abiraterone and other secondary hormone therapy
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