Malignant neoplasm prostate

Prostate cancer, one of the most common types of cancer in men, involves the growth of cancerous cells in the prostate gland. It varies widely in its aggressiveness and potential to cause harm.

Causes:

  • Age: Risk increases with age, particularly after 50.
  • Family History: Higher risk if a father or brother has had prostate cancer.
  • Race: More common in African-American men.
  • Genetics: Mutations in certain genes (like BRCA1 and BRCA2) can increase risk.
  • Diet and Lifestyle: High-fat diet and obesity may increase risk.

Screening:

  • Prostate-Specific Antigen (PSA) Test: Measures PSA levels in the blood. Elevated levels can indicate cancer but also other conditions.
    • Levels > 3 demand a repeat in 1-3 months with abstinence from prostate stimulation for 3/7 (ie no sex, bike riding)
    • A repeat results > 3 should be refered to a Urologist for an MRI or other Ix (AKT 2023.1 and AKT 2022.2 Q&A)
  • Digital Rectal Exam (DRE): Is not typically recommended
  • MRI: Can image the prostate in detail but is not covered under the MBS
  • Screening Guidelines: Men should discuss the benefits and risks of screening with their doctor.

Diagnosis:

  • Biopsy: If screening tests  suggest cancer, a biopsy is performed to confirm diagnosis.
    • Transrectal carries a relatively high infection risk.
    • Transperineal carries a relatively high errectile dysfunction risk.
  • Imaging: MRI, CT scans, or bone scans to determine if cancer has spread.

Differential Diagnosis:

  • Benign Prostatic Hyperplasia (BPH): Non-cancerous enlargement of the prostate.
  • Prostatitis: Inflammation or infection of the prostate.
  • Urinary Tract Infections (UTIs): Can cause symptoms similar to prostate cancer.

Management

  • Active Surveillance:
    • Regular Monitoring: Includes PSA blood tests, digital rectal exams (DRE), and biopsies at intervals.
    • Goal: To avoid or delay more aggressive treatments in men with less aggressive cancer, particularly if it’s not causing symptoms or expected to progress rapidly.
  • Surgery (Prostatectomy):
    • Radical Prostatectomy: Removes the entire prostate gland, surrounding tissue, and seminal vesicles.
    • Techniques: Can be done through open surgery, laparoscopically, or using robot-assisted methods.
    • Side Effects: Risk of urinary incontinence and erectile dysfunction.
  • Radiation Therapy:
    • External Beam Radiation: Uses high-energy beams to target the prostate.
    • Intensity-Modulated Radiation Therapy (IMRT): More precisely targets cancer, limiting damage to surrounding tissue.
    • Brachytherapy: Radioactive seeds implanted in the prostate.
    • Side Effects: Irritation of the bladder and bowel, erectile dysfunction, fatigue.
  • Hormone Therapy:
    • Androgen Deprivation Therapy (ADT): Lowers levels of male hormones (androgens) to shrink or slow the growth of cancer.
    • Methods: Surgical castration or drugs (like LHRH agonists or antagonists).
    • Side Effects: Hot flashes, erectile dysfunction, loss of bone mass, reduced libido, weight gain.
  • Chemotherapy:
    • Uses: Typically for cancer that has spread beyond the prostate or for hormone-resistant cancer.
    • Drugs: Administered intravenously or orally to kill cancer cells.
    • Side Effects: Fatigue, nausea, hair loss, increased risk of infection.
  • Immunotherapy:
    • Sipuleucel-T: A treatment that stimulates the immune system to attack prostate cancer cells.
    • Indications: For advanced prostate cancer.
  • Targeted Therapy:
    • PARP Inhibitors: For cancers with specific genetic changes.
    • Mechanism: Targets cancer cell DNA repair mechanisms.
  • Bone-Directed Therapy:
    • Bisphosphonates or RANKL Inhibitors: To strengthen bones and reduce fracture risk in men whose cancer has spread to bone.
    • Radiopharmaceuticals: Deliver radiation directly to bone metastases.

Lifestyle and Support:

  • Diet: Emphasizing fruits, vegetables, whole grains, and lean proteins. Reducing red meat, fats, and processed foods.
  • Exercise: Regular exercise to help manage side effects, improve energy levels, and overall health.
  • Psychological Support: Counseling and support groups to address mental and emotional health challenges.

Managing Side Effects:

  • Physical Therapy: For urinary incontinence post-surgery.
  • Erectile Dysfunction Treatments: Medications, vacuum devices, or penile implants.
  • Bone Health: Calcium and vitamin D supplements, weight-bearing exercises.

Follow-Up Care:

  • Regular PSA Testing: To monitor for recurrence.
  • Medical Check-Ups: Including physical exams and, if necessary, imaging tests.

The choice of treatment should be made after thorough discussion with healthcare providers, considering the potential benefits and risks of each option. Patient preference and quality of life considerations are crucial in decision-making.

Androgen Deprivation

Androgen deprivation therapy (ADT) is a cornerstone in the treatment of advanced prostate cancer. It aims to reduce the levels of androgens (male hormones) in the body because androgens stimulate prostate cancer cells to grow. The following are the primary androgen deprivation options for prostate cancer:

  1. Gonadotropin-Releasing Hormone (GnRH) Agonists: These drugs, such as leuprolide, goserelin, and triptorelin, lower the amount of testosterone made by the testicles. They are administered via injections or implants.
  2. GnRH Antagonists: Drugs like degarelix work by directly blocking the action of gonadotropin-releasing hormone on the pituitary gland, which leads to a rapid decrease in testosterone production. Unlike GnRH agonists, they do not cause an initial testosterone surge.
  3. Anti-Androgens: These medications, including bicalutamide, flutamide, and nilutamide, block the action of androgens at their receptor sites in the tumor cells. They are often used in combination with GnRH agonists or after surgical removal of the testicles.
  4. Orchiectomy (Surgical Castration): This surgical procedure involves the removal of the testicles, which are the body’s main source of testosterone. It is a more permanent solution and has the same effect as medical castration with drugs.
  5. Newer Hormonal Agents: Drugs like abiraterone and enzalutamide represent newer classes of medications. Abiraterone works by blocking the production of androgens not only by the testicles but also by the adrenal glands and the tumor itself. Enzalutamide is a more potent anti-androgen that blocks the signaling of androgens at the receptor level.
  6. Intermittent Androgen Deprivation: This approach involves cycling periods of androgen deprivation treatment with periods of no treatment. The goal is to maintain the effectiveness of the therapy while minimizing side effects.