male reproductive health

Male Reproductive Health Study Notes

Overview of Topics Covered

  • Testicular Cancer

  • Benign Prostatic Hyperplasia (BPH)

  • Prostate Cancer

  • Erectile Dysfunction (ED)

Testicular Cancer

Incidence and Significance

  • Represents 1% of all male cancers.

  • Primarily affects men aged 15-35.

  • One of the most curable cancers.

Risk Factors

  • Cryptorchidism: Condition where one or both testicles have not descended.

  • Family History: Increased risk if family members have had testicular cancer.

  • Caucasian: Higher incidence in Caucasians compared to other ethnic groups.

  • HIV Infection: Increased risk associated with HIV.

Germ Cell Tumors (95% of Testicular Cancers)

  • Seminomas:
      - Arise from immature germ cells.
      - Characterized as slow-growing and nonaggressive.
      - Generally treatable using radiation.

  • Non-seminomas:
      - Arise from mature germ cells.
      - More aggressive and usually treated with surgery.

Early Clinical Manifestations

  • Enlargement of testicle

  • Painless mass: (noted in most cases)

  • Discomfort present in 30-40% of patients, described as:
      - Dull ache in the groin.
      - Sensation of heaviness.

Late Clinical Manifestations

  • Possible acute pain.

  • Symptoms related to metastatic spread may include:
      - Cough
      - Hemoptysis
      - Swelling of lower extremities
      - Back pain
      - Dizziness

Benign Prostatic Hyperplasia (BPH)

Overview

  • Definition: Nonmalignant enlargement of the prostate gland.

  • Characterized by:
      - Increased epithelial cells (average 11.9%).
      - Increased smooth muscle cells (average 38.8%).
      - Increased stromal cells (average 38.6%).

  • Linked to Lower Urinary Tract Symptoms (LUTS).

Risk Factors

  • Non-modifiable:
      - Age
      - Family history
      - Race/Ethnicity

  • Modifiable:
      - Obesity and metabolic syndrome
      - Caffeine intake
      - Physical activity

Etiology

Two Theories

  1. Hormone Imbalance
       - Interaction of testosterone and estrogen (estradiol).

  2. DHT Accumulation
       - Di-hydrotestosterone (DHT) is formed from testosterone by the enzyme 5 alpha-reductase.
       - DHT acts on skin and hair follicles influencing acne and body hair but leading to hair loss on the scalp, and stimulates prostate cell growth.

Clinical Manifestations

  • Symptoms include:
      - Frequent urination and urgency.
      - Increased time to urinate.
      - Dribbling of urine.
      - Delay in initiation of urination.
      - Reduced force of urine stream.
      - Urination at night (nocturia).
      - Inability to completely empty the bladder, possibly leading to urinary tract infections.

Complications

  • Obstruction of urinary flow: resulting from enlarged prostate.

  • Increased risk of UTIs.

  • Renal problems due to bladder overdistension.

Treatment Options

  • Mild Symptoms: Watchful waiting approach.

  • Moderate Symptoms: Drug therapy including:
      - 5-alpha reductase inhibitors (e.g., Finasteride, Dutasteride).
      - Alpha1-adrenergic antagonists (e.g., Tamsulosin).

  • Severe Symptoms: Consideration of invasive options.

5-Alpha Reductase Inhibitors

  • Finasteride (Proscar):
      - Indication: Mechanical obstruction due to prostate enlargement.
      - Mechanism of Action (MOA): Blocks conversion of testosterone to DHT; reduces epithelial tissue in prostate.
      - Adverse Effects:
        - Impotence
        - Decreased libido (5-10%)
        - Gynecomastia.
      - Side note on PSA: Decreases prostate-specific antigen levels and is also used in treating male-pattern baldness.

  • Dutasteride (Advodart):
      - Similar functions to Finasteride but blocks both alpha 1 and alpha 2 receptors.

Alpha1-Adrenergic Antagonists

  • Tamsulosin (Flomax):
      - Mechanism of Action: Relaxes smooth muscle in the prostate.
      - Designed for dynamic obstruction of the urethra caused by prostate enlargement.
      - Adverse effects: Generally well-tolerated, though can cause abnormal ejaculation.

Combination Therapy

  • Prototype: Combination of Dutasteride (Avodart) and Tamsulosin (Flomax) known as Jalyn.

  • FDA Approved: For use in BPH, as combining a 5-alpha-reductase inhibitor with an alpha blocker yields better results than either agent used alone.

Prostate Cancer

Overview

  • Prostate Cancer: The most common cancer in men in the U.S.

  • It is the second leading cause of cancer-related death after lung cancer.

  • Incidence and Ethnicity:
      - Higher rates observed in African-American men.
      - Lowest rates found in Asians and Native Americans.
      - Incidence increases sharply after age 50.
      - Over 80% of cases in men over 65 years old.

Risk Factors

  • Age

  • Ethnicity

  • Familial tendency

  • High-fat diet

Clinical Manifestations

  • Early Manifestations: Similar to those of BPH.

  • Later Manifestations: Metastasis possibly affecting:
      - Bones
      - Lungs

  • Prognosis: Varies depending on stage and early diagnosis pivotal for better outcomes.

Controversy Surrounding Prostate Cancer

  • While prostate cancer is a leading cause of cancer death, many cases are slow-growing and non-lethal.

  • PSA screening was widely adopted before definitive evidence supporting its effectiveness was available.

Benefits and Harms of PSA Screening

  • Benefits: Small survival advantage in large randomized trials.

  • Harms:
      - Need for 48 diagnoses to prevent 1 death.
      - Positive PSA tests often lead to unnecessary biopsies.
      - Side effects of treatments may include erectile dysfunction, urinary incontinence, bowel problems.

Prognosis Factors

  • Severity of prostate cancer categorized into low, intermediate, and high-grade.

  • Key prognostic factors:
      - Gleason score: Higher scores indicate worse prognosis.
      - Tumor volume.
      - PSA levels: High and rapidly increasing levels indicate worse outcomes.
      - Number of positive cores in biopsy: More positive cores suggest worse prognosis.
      - Detection method: PSA vs Digital Rectal Exam (DRE).

Erectile Dysfunction (ED)

Overview

  • Definition: A condition also called “Impotence” characterized by the inability to achieve or maintain an erection sufficient for satisfactorily engaging in sexual intercourse.

  • Significance: Affects approximately 30 million men in the U.S., often linked to chronic illness.

Classification of ED

  • Primary ED: Very rare, associated with lifelong inability to have normal erections due to severe psychiatric problems or early vascular trauma.

  • Secondary ED: More common, occurs in men with a prior history of normal erections.

Etiology of Secondary ED

  • Organic Causes:
      - Peripheral vascular disease (arterial insufficiency, excessive venous drainage).
      - Sedentary lifestyle as a risk factor.

  • Psychogenic Causes:
      - Depression
      - Performance anxiety
      - Strained relationships
      - Trauma and surgery (e.g., radical prostatectomy).

  • Endocrine Issues: Related to hormonal imbalances.

  • Medications: Such as antidepressants and antihypertensives that may lower sexual desire.

Physiology of a Normal Erection

  • Triggered by sexual arousal, leading to increased PNS (parasympathetic nervous system) and nitric oxide release.

  • Activation of cGMP results in the relaxation of arteries and smooth muscles.

  • Increased blood inflow and reduced outflow lead to engorgement and resultant erection.

  • PDE-5 (phosphodiesterase type 5) breaks down cGMP.

PDE-5 Inhibitors

Example: Sildenafil (Viagra)

  • Mechanism of Action: Inhibits PDE5, preserving cGMP levels, which assists in achieving erection only in response to sexual stimuli.

  • Indications:
      - Relief of ED
      - Treatment for pulmonary arterial hypertension
      - Utilized in BPH.

  • Timing of Drug: Can be taken up to 4 hours before sexual activity, with onset typically within 30-60 minutes.

  • Adverse Effects:
      - Headaches (common, affecting 16% of users)
      - Flushing (10%)
      - Dyspepsia (7%).

  • Cautions:
      - Avoid use with nitrates and be cautious if heart disease is present.
      - Monitor for hypotension.

Safety Issues with Sildenafil Usage

  • Contraindications: Do not use with nitrates.

  • Emergency Signs:
      - Chest pain or signs of heart attack during sexual activity requires immediate medical attention.
      - Sudden loss of vision or hearing should be reported.

  • Use Limitations: No more than once daily.

  • Priapism: An erection lasting more than 4 hours is a medical emergency requiring immediate treatment.

References

  • Lynn Kelso DNP, APRN, FCCM, FAANP

  • Capriotti, T. M., & Frizzell, J. P. (2015). Pathophysiology: Introductory concepts and clinical perspectives. FA Davis Company.

  • Nickel JC. Comparison of clinical trials with finasteride and dutasteride. Rev Urol. 2004;6 Suppl 9(Suppl 9):S31–S39.

  • Dimitropoulos, K., & Gravas, S. (2016). Fixed-dose combination therapy with dutasteride and tamsulosin in the management of benign prostatic hyperplasia. Therapeutic advances in urology, 8(1), 19-28.

  • https://www.uptodate.com/contents/risk-factors-for-prostate-cancer?search=prostate%20cancer&topicRef=6939&source=see_link

  • https://www.uptodate.com/contents/epidemiology-of-and-risk-factors-for-testicular-germ-cell-tumors?search=testicular%20cancer%20risk%20factors&source=search_result&selectedTitle=1~150&usage_type=default&display_rank=1