Prostate cancer

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management

Definition

Prostate cancer is a malignant tumour originating in the prostate gland. It is the most common cancer in men in the UK and has a variable course, ranging from indolent to aggressive disease.

Aetiology

Prostate cancer arises due to genetic mutations leading to uncontrolled prostate cell growth.

Types of Prostate Cancer:

  • Adenocarcinoma (95%): the most common histological type.
  • Small cell carcinoma: aggressive and rare.
  • Squamous cell carcinoma: rare and poorly responsive to treatment.

Pathophysiology

  • Mutations in tumour suppressor genes (e.g., BRCA1, BRCA2, PTEN) lead to uncontrolled growth.
  • Testosterone and dihydrotestosterone (DHT) promote tumour progression.
  • Prostate cancer typically originates in the peripheral zone and spreads locally to the seminal vesicles, bladder, and rectum.
  • Advanced disease spreads via lymphatics (pelvic lymph nodes) and haematogenous routes (bones, liver, lungs).

Risk Factors

  • Age >50 years.
  • Family history of prostate cancer (BRCA gene mutations increase risk).
  • Ethnicity (higher incidence in Black African and Caribbean men).
  • Obesity and high fat diets.
  • Smoking (associated with aggressive prostate cancer).

Signs and Symptoms

Localised Disease:

  • Often asymptomatic (detected via PSA screening).
  • Lower urinary tract symptoms (LUTS): frequency, urgency, weak stream, nocturia.
  • Haematuria or haematospermia: may occur in some cases.

Advanced or Metastatic Disease:

  • Bone pain: commonly affects the spine, pelvis, and ribs.
  • Pathological fractures: due to bone metastases.
  • Weight loss and fatigue: systemic signs of malignancy.
  • Lower limb oedema: due to lymphatic obstruction.
  • Spinal cord compression: back pain, lower limb weakness, and incontinence (oncological emergency).

Investigations

  • Prostate-Specific Antigen (PSA): elevated in prostate cancer but also in benign conditions (BPH, prostatitis).
  • Digital Rectal Examination (DRE): hard, irregular prostate suggests malignancy.
  • Multiparametric MRI (mpMRI): first line imaging for suspected prostate cancer.
  • Transrectal Ultrasound (TRUS) Biopsy: confirms histological diagnosis.
  • Bone Scan: assesses for skeletal metastases in advanced disease.
  • CT/MRI Pelvis: staging to detect lymph node involvement.

Management

1. Localised Disease (Low-Risk):

  • Active surveillance: for low risk disease (PSA <10, Gleason <6, localised tumour).
  • Radical prostatectomy: surgical removal of the prostate.
  • Radiotherapy: external beam radiotherapy or brachytherapy.

2. Locally Advanced Disease:

  • Radiotherapy + Androgen Deprivation Therapy (ADT): used for higher-risk cases.
  • Surgery: considered in selected cases.

3. Metastatic Disease:

  • Androgen Deprivation Therapy (ADT): first line treatment (e.g., LHRH agonists like Leuprorelin).
  • Docetaxel Chemotherapy: used in hormone-sensitive advanced disease.
  • Newer agents: enzalutamide or Abiraterone (for castration-resistant disease).
  • Radiotherapy: palliative in bone metastases.

4. Palliative Care:

  • Pain management (opioids for bone pain).
  • Palliative radiotherapy for bone metastases.
  • Supportive care for patients with advanced disease.
RenalmypanotesProstate cancer