Urinary Tract Disorders - Prostate Diseases

BPH

  • Definition: Benign Prostatic Hyperplasia (BPH) is a non-neoplastic enlargement of the prostate gland, leading to lower urinary tract symptoms (LUTS).

  • Prevalence: Common in men > 60 years, with increasing prevalence with age, but only approximately 50% show clinical symptoms.

  • Pathology:

    • Enlarged prostate with nodule formation, predominantly in the transition zone.

    • Histology shows fibromuscular & glandular hyperplasia. Increased number of stromal and glandular cells.

  • Pathogenesis: Related to the influence of androgens, particularly dihydrotestosterone (DHT), on prostate cells. Levels of male sex hormones (testosterone) and the conversion of testosterone to DHT by 5-alpha reductase play a crucial role.

  • Pathology (Detailed): Nodular hyperplasia affecting stroma (smooth muscle and fibrous tissue) and glands, particularly in the lateral & median lobes, leading to compression of the urethra and bladder outflow obstruction. The transition zone of the prostate is most commonly affected. Microscopic examination reveals an increased number of both stromal and glandular cells.

  • Symptoms:

    • Hesitancy in initiating micturition.

    • Weak or intermittent (poor) stream.

    • Dribbling postmicturition.

    • Increased urinary frequency and nocturia.

    • Urgency and incomplete emptying.

  • Other Clinical Features:

    • Acute urinary retention (complete inability to pass urine).

    • Chronic urinary retention (incomplete bladder emptying).

    • Cystitis (bladder infection) due to urinary stasis.

    • Bladder hypertrophy and trabeculation (thickening of the bladder wall).

    • Hydronephrosis (swelling of the kidneys due to backflow of urine) and pyelonephritis (kidney infection) in severe cases.

  • Investigation:

    • Rectal examination: Enlarged prostate (firm, smooth & rubbery).

    • Abdominal examination: Enlarged palpable bladder if urinary retention is present.

    • Urine analysis: to rule out infection or hematuria.

    • PSA (Prostate-Specific Antigen) test: to screen for prostate cancer (BPH can also elevate PSA).

    • Uroflowmetry: measures the rate and volume of urine flow.

    • Post-void residual volume measurement: assesses bladder emptying.

    • Ultrasound (Transrectal or abdominal): to assess prostate size and rule out other abnormalities.

  • Treatment:

    • Medical:

      • α\alpha-blockers (e.g., Tamsulosin, Alfuzosin): Relax smooth muscle at the bladder neck and prostate, improving urine flow.

      • 5-alpha reductase inhibitors (e.g., Finasteride, Dutasteride): Prevent testosterone conversion to DHT, reducing prostate size over time.

      • Combination therapy: α\alpha-blocker + 5-alpha reductase inhibitor for men with larger prostates.

    • Surgical:

      • Transurethral resection of the prostate (TURP): Surgical removal of prostate tissue obstructing the urethra. Monopolar or bipolar.

      • Transurethral incision of the prostate (TUIP): Incisions are made in the prostate to widen the urethra (suitable for smaller prostates).

      • Open prostatectomy: Surgical removal of the prostate gland (usually for very large prostates).

    • Minimally Invasive Procedures:

      • Prostate artery embolization (PAE): Blocks blood supply to the prostate, causing it to shrink.

      • Water vapor thermal therapy (Rezum): Uses steam to ablate prostate tissue.

      • UroLift: Places implants to lift and hold the enlarged prostate tissue out of the way, increasing the opening of the urethra.

Prostate Cancer

  • Prevalence: Very common, the second most common cancer in men (after lung), accounting for a significant proportion of all cancers in men. Incidence increases with age.

  • Age: A disease of elderly men, occurring in 1 in 10 men >70 years, rare < 55 years. Risk significantly increases after age 50.

  • Aetiology:

    • Unknown, but linked to androgen hormones and tumour growth.

    • Genetic factors: Mutations in genes such as BRCA1/2, HOXB13, and mismatch repair genes increase risk.

    • Hormonal changes with increasing age may be involved; includes androgens & hypersensitivity of androgen receptor.

    • Family history: strong hereditary component; men with a family history of prostate cancer have a higher risk.

    • Often associated with BPH but no proof of causal relationship. Both conditions are common in older men.

  • Pathology:

    • Adenocarcinoma (most common type).

    • Acinar adenocarcinoma: the most prevalent subtype.

    • Mostly in the peripheral zone, classically posterior location. This is why DRE (digital rectal exam) is useful for detection.

    • Grading: Gleason grading system (scores range from 6-10, based on glandular differentiation and architectural patterns).

    • Staging: TNM (Tumor, Node, Metastasis) staging system is used to determine the extent of the cancer.

    • Spread:

      • Local: floor of bladder & pelvis, other adjacent structures.

      • Distant metastases: bone (esp. spine, pelvis, femur, ribs); liver & lungs. Lymph node involvement is also common.

  • Presentation:

    • Symptoms of lower urinary tract obstruction (similar to BPH).

    • Hard craggy prostate on rectal examination.

    • Metastatic disease in the bone; pain, fractures, spinal cord compression.

    • Asymptomatic carcinoma, found incidentally during workup for other conditions or in autopsies.

  • Diagnosis:

    • Digital rectal examination (DRE): to assess prostate size and texture.

    • Transrectal ultrasound (TRUS) with biopsy: Gold standard for diagnosis. Guides the biopsy needles to specific areas.

    • Prostatic biopsy: histological diagnosis & Gleason scoring. Multiple cores are taken to improve accuracy.

    • Prostate-specific antigen (PSA) - elevated levels can indicate prostate cancer, but also BPH or prostatitis. Use with caution.

    • Further testing: MRI – detailed structure if significant chance of spreading; recent advance: mpMRI (multiparametric MRI), which improves detection and characterization of prostate lesions. EN2: recent discovery by Surrey Team.

    • Genomic testing: can help assess the aggressiveness of the cancer.

  • Treatment:

    • Active surveillance: monitoring low-risk cancers with regular PSA tests and biopsies.

    • Surgery – radical prostatectomy (open, laparoscopic, or robotic-assisted).

    • Radiation therapy: external beam radiation therapy (EBRT) or brachytherapy (internal radiation).

    • Hormone therapy: LHRH agonists or antagonists, anti-androgens. Used to suppress testosterone production.

    • Chemotherapy: for advanced or metastatic disease.

    • Immunotherapy: Newer treatments like sipuleucel-T may be used in some cases.

  • Prognosis: Depends on the stage, Gleason score, PSA level, and overall health of the patient. Early detection improves prognosis.

Prostate Anatomy

  • The prostate is a gland that surrounds the bladder neck and proximal urethra.

  • It has four zones: central, peripheral, transitional, periurethral. The transition zone is the site of most BPH, while the peripheral zone is the site of most prostate cancers.

Overview

  • The prostate is a gland that surrounds the urethra and slowly grows with age.

  • Prostate diseases are very common > age 50.

  • Common prostate diseases:

    • Benign prostatic hyperplasia.

    • Prostate cancer.

    • Prostatitis (an infection, usually caused by bacteria or other pathogens). Can be acute or chronic.