male repro

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

  • Testicular cancer comprises 1% of all male cancers.

  • It is a major cancer diagnosed in men aged 15-35 years.

  • Testicular cancer is noted for being highly curable.

Risk Factors

  • Cryptorchidism: Undescended testicle, which increases cancer risk.

  • Family History: Genetic predisposition to cancer.

  • Caucasian Ethnicity: Higher incidence among Caucasian men.

  • HIV Infection: Associated with increased risk of testicular cancer.

Types of Testicular Cancer

  • Germ Cell Tumors (95% of cases): Divided into two categories:
      - Seminomas:
        - Originates from immature germ cells.
        - Characterized as slow-growing and non-aggressive.
        - Generally curable with radiation.
      - Nonseminomas:
        - Begins from mature germ cells.
        - More aggressive than seminomas.
        - Typically treated with surgery.

Early Clinical Manifestations

  • Enlargement of the testicle.

  • Painless mass; noted in most cases.

  • In some instances (30-40% of cases), discomfort may occur:
      - Dull ache in the groin.
      - Sensation of heaviness in the testicle.

Late Clinical Manifestations

  • Possible acute pain may present.

  • Manifestations may vary based on metastatic spread, which can include:
      - Cough
      - Hemoptysis (coughing up blood)
      - Swelling of lower extremities
      - Back pain
      - Dizziness

Benign Prostatic Hyperplasia (BPH)

Definition and Risk Factors

  • BPH refers to the nonmalignant enlargement of the prostate gland.

  • Average epithelial cells increase to 11.9%, smooth muscle cells 38.8%, and stromal cells 38.6%.

  • Symptoms typically describe as Lower Urinary Tract Symptoms (LUTS).

Risk Factors

  • Non-modifiable Risk Factors:
      - Age: Risk increases as men age.
      - Family history: Genetics play a role.
      - Race/Ethnicity: Varies among groups.

  • Modifiable Risk Factors:
      - Obesity and metabolic syndrome
      - Caffeine consumption
      - Physical activity: Lack thereof increases risk.

Etiology of BPH: Two Theories

  1. Hormonal Imbalance: Change in hormone levels, particularly testosterone and estradiol.

  2. DHT Accumulation:
       - Dihydrotestosterone (DHT) is formed by the conversion of testosterone via 5 alpha-reductase.
       - Importance of DHT:
         - Influences skin (acne) and hair follicles (hair growth on the chest but loss on the scalp).
         - Stimulates prostate cell growth leading to BPH.

Clinical Manifestations

  • Common symptoms include:
      - Frequency and urgency of urination
      - Increased time to urination
      - Dribbling at the end of urination
      - Delay in initiating urination
      - Weak urine stream
      - Inability to completely empty the bladder
      - Urinary tract infection (UTI): Can occur due to obstruction.

Complications of BPH

  • Obstruction to urinary flow.

  • Increased risk of UTIs.

  • Renal problems due to blockages, potentially leading to kidney damage.

Treatment Options for BPH

  • Mild symptoms: Watchful waiting may be advised.

  • Moderate symptoms: Medication such as:
      - 5-alpha reductase inhibitors (e.g., Finasteride).
      - Alpha1-adrenergic antagonists.

  • Severe symptoms: Consider surgical options or minimally invasive procedures.

5-alpha Reductase Inhibitors

  • Finasteride (Proscar):
      - Indication: Mechanical obstruction of the urethra.
      - Mechanism of Action (MOA): Blocks the conversion of testosterone to DHT, reducing prostate tissue.
      - Adverse Effects: May include impotence, decreased libido (5-10% incidence), gynecomastia, and reduced prostate-specific antigen (PSA) levels.
      - Caution: Handle drug cautiously, especially for women who are pregnant.

  • Dutasteride (Avodart):
      - Similar indications and MOA to Finasteride but may act on both alpha-1 and alpha-2 receptors.

Alpha1-Adrenergic Antagonists

  • Tamsulosin (Flomax):
      - Indication for treating dynamic obstruction of the urethra.
      - MOA: Relaxes smooth muscle tissue in the prostate, easing urinary flow.
      - Adverse Effects: Generally well-tolerated but may have abnormal ejaculation as a side effect.

Combination Therapy

  • Prototype: Dutasteride + Tamsulosin (Jalyn).
      - FDA approved for use in BPH.
      - Evidence shows that this combination is more effective than using either drug alone.

Prostate Cancer

Overview

  • Prostate cancer is the most common cancer in men in the U.S.

  • It is the second leading cause of cancer-related deaths, following lung cancer.

  • Incidence varies by race:
      - African-American men have the highest risk.
      - Asians and Native Americans have the lowest.

  • Incidence rises sharply after the age of 50, with over 80% of cases diagnosed in men over 65.

Risk Factors for Prostate Cancer

  • Age: Older males are at increased risk.

  • Ethnicity: Notable differences based on race.

  • Familial predisposition: Strong familial tendency toward prostate cancer.

  • Diet: High-fat diets may contribute to risk.

Clinical Manifestations

  • Early Stage:
      - May present similarly to BPH.

  • Later Stage:
      - Commonly presents with metastasis to bones and lungs.

Prognosis

  • The prognosis of prostate cancer is stage-dependent.

  • Important factors in prognosis include:
      - Gleason score: A higher score indicates more aggressive disease.
      - Tumor volume: The size of the tumor plays a role in severity.
      - PSA level: Rapid increase in PSA or higher initial levels indicate worse prognosis.
      - Number of positive biopsy cores: More cores with positive cancer indicate worse prognosis.

The Controversy of PSA Screening

  • Prostate cancer often leads to death, but many cases may not progress to clinical significance.

  • Many prostate cancers grow slowly, and men typically die from other causes.

  • PSA screening issues:
      - Initially adopted without sufficient evidence of its efficacy.
      - Only about 1 in 3 men with a positive PSA test actually have prostate cancer, often leading to unnecessary biopsies.
      - Unwanted treatment side effects include erectile dysfunction, urinary incontinence, and bowel complications.

Benefits and Harms of PSA Testing

  • Benefits:
      - Linked to a 50% drop in prostate cancer deaths in the U.S.
      - Small overall survival benefit with PSA screening; only prevents 1 death for every 48 diagnoses.

  • Harms:
      - Risk of unnecessary invasive procedures and their associated side effects.

Erectile Dysfunction (ED)

Definition

  • ED, or impotence, refers to the inability to achieve or maintain an erection adequate for satisfactory sexual intercourse.

Significance of ED

  • 30 million men in the U.S. experience ED.

  • Often associated with chronic illnesses.

Classification of ED

  • Primary ED (rare): Lifelong inability to achieve erections, linked to severe psychiatric issues or early trauma.

  • Secondary ED (most common): Occurs in men who have previously experienced normal erections.

Etiology of Secondary ED

  1. Organic Causes:
       - Peripheral Vascular Disease:
         - Arterial insufficiency and excessive venous drainage.
         - Sedentary lifestyle as a risk factor.
       - Endocrine Problems: Hormonal imbalances contributing to ED.

  2. Psychogenic Causes:
       - Factors such as depression, performance anxiety, and strained relationships may contribute to ED.
       - Trauma or surgical histories (e.g., radical prostatectomy) also factor into incidents of ED.

Physiology of a Normal Erection

  • Sexual arousal triggers the parasympathetic nervous system (PNS), leading to:
      - Release of nitric oxide.
      - Activation of cyclic guanosine monophosphate (cGMP) causing vascular relaxation.
      - Increased inflow of blood and reduced outflow, resulting in engorgement and erection.

  • Phosphodiesterase type 5 (PDE-5) breaks down cGMP, reducing erection strength.

PDE-5 Inhibitors

  • Prototype: Sildenafil (Viagra):
      - MOA: Inhibits PDE5, increasing cGMP levels.
      - Enhances normal responses to sexual stimuli.
      - Indications: Relief of ED, pulmonary arterial hypertension, and BPH.

Timing and Adverse Effects of Sildenafil

  • Timing: Take up to 4 hours before sex; onset of effect is 30-60 minutes.

  • Adverse Effects:
      - Most common include headaches (16%), flushing (10%), and dyspepsia (7%).

  • Cautions:
      - Potentially major issues for patients with cardiovascular diseases or those taking nitrates.
      - Hypotension may occur in combination with nitrate medications.

Safety Issues for Patients on Sildenafil

  • Avoid if taking nitrates.

  • If experiencing chest pain during sex, call 911 immediately.

  • Signs of sudden vision or hearing loss must be reported to a physician.

  • Do not take more than once a day.

  • Priapism (prolonged erection lasting over 4 hours) is a medical emergency.

References

  • Thanks to 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.

  • Sources from UpToDate on prostate cancer and testicular germ cell tumors.