Prostate Cancer

Most common type of cancer affecting men 50+ in the UK

Aetiology

  • Rare before age 40, prevalence increases with age
  • Genetic factor - risk >2x if one first degree relative
  • BPH is NOT pre-malignant prostate cancer, but both can occur in the same patient

Risk factors

  • Cadmium batteries
  • Less hormonal link than BL
  • Cause is far less clear compared to other cancers

Pathophysiology

  • Prostate has 3 zones:
    • Central zone - surrounds ejectulatory ducts
    • Peripheral zones - posterolateral, where malignant cancers arise
    • Transitional zones - surounds prostatic urethra, where BPH occurs

Clinical presentation

  • Early prostate cancer is asymptomatic
  • Haematospermia
  • Haematuria - particularly terminal
  • Obstruction - hesitancy, reduced flow
  • Bone pain - most common site of metastasis
  • Constitutional symptoms - weight loss, anorexia, fatigue

Investigations

Bloods - PSA

  • Raised in prostate cancer but also BPH, prostatitis, ejaculation)
  • Glucoprotein enzyme - kallikrein 3
  • Liquifies semen in ejeculate and allows sperm to swim
  • Very high grade cancers won't produce it - high grade means they act less and less resemble the cell of origin

PR exam

  • Enlarged, hard, irregular, asymmetrical prostate
  • Prostatic cancer typically arises from the posterior lobe and on the periphery

Trans-rectal US-guided biopsy

  • Prostate cancers are unique because more than one tumour can have multiple morphologies
  • Gleason score - the two most common morphologies are determined, then their scores are added together giving a score /10 which determines prognosis
  • Then TNM staging
    • Tumour invasion (T1-T4)
    • Lymph node involvement (N0/1)
    • Metastasis (N0/1)

Imaging

  • Spread can be determined by MRI and bone scan
    • Bone scan will reveal osteosclerosis - most malignancy causes osteolysis

Management

  • Most are low grade, localised and slow growing - even when diagnosed they are only followed up
  • Medium/high risk, localised - prostatectomy, radiotherapy
  • Advanced - LHRH agonists, anti-androgens
    • Inhibits testosterone which slows the progression of prostate cancer
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