Description

• The prostate is a male reproductive organ that contributes seminal fluid to the ejaculate.
• The prostate gland is about the size of a walnut, averaging 20 to 25 g in volume in an adult male; tends to enlarge after age 50
• Three distinct zones delineate the functional anatomy of the prostate: peripheral zone (largest, neighbors rectal wall, palpable on digital rectal exam [DRE], most common location for prostate cancer), central zone (contains the ejaculatory ducts), and transition zone (located centrally, adjacent to the urethra).
• Prostatic epithelial cells produce prostate-specific antigen (PSA), which is used as a tumor marker and in screening.

Epidemiology

Incidence
An estimated 248,530 men in the United States will be newly diagnosed with carcinoma of the prostate (CaP) in 2021, representing 13.1% of all new cancer diagnoses.

Prevalence

• An estimated 34,130 men in the United States will die of CaP in 2021, representing 5.6% of all cancer deaths.
• Median age at diagnosis is 67 years; probability of CaP 10.9% (1 in 9) ≥70 years
• PCa most commonly diagnosed nonskin cancer in men in the United States (~12.1% lifetime risk) and second leading cause of cancer death in men (only ~3% of all CaP results in CaP-related death.)
• Autopsy studies find foci of latent CaP in 50% of men in their 8th decade of life.

Etiology and Pathophysiology

• Adenocarcinoma: >95%; nonadenocarcinoma: <5% (most common transitional cell carcinoma)
• Location of CaP: 70% peripheral zone, 20% transitional zone, 5–10% central zone

Risk Factors

Age >50 years, African American race, positive family history

General Prevention

There are no FDA-approved drugs or diet modifications to prevent CaP.

• Finasteride use associated with moderate risk reduction in CaP but associated with an increased risk of high-grade disease.

• U.S. Preventive Services Task Force (USPSTF): “for men aged 55 to 69 years, the decision to undergo periodic PSA-based screening for prostate cancer should be an individual one and should include discussion of the potential benefits and harms of screening with their clinician. Screening offers a small potential benefit of reducing the chance of death from prostate cancer in some men. However, many men will experience potential harms of screening” (1)[A]. USPSTF recommends against PSA screening for men ≥70 years old (1)[A].
• The American Urological Association (AUA) panel recommends for men 55 to 69 shared decision-making between physician and patient regarding PSA screening.
• PSA screening is not recommended in men age <40 years or any man with <10 years of estimated life expectancy.
• When providing informed consent, data shows if you screen 1,000 men between 55 and 69 years:
  • 240 will have a positive result; only ~100 will truly have PCa; of the 100 with cancer, 80 will agree to treatment.
  • Treatment will result in one less person dying, but 50 will develop erectile dysfunction (ED); 15 permanent incontinence