Everything You Need to Know About Prostate cancer for Step 1

Prostate cancer shows up everywhere on Step 1: it’s common, it’s high-yield, and question writers love testing how it differs from benign prostatic hyperplasia (BPH), how PSA behaves, and what you do after an abnormal screen. If you can connect androgens → peripheral gland → PSA/DRE → biopsy → staging/therapy, you’ll crush a big chunk of male reproductive pathology.

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Where Prostate Cancer Fits (and Why Step 1 Loves It)

• Most common non-skin cancer in men (US); risk increases with age.
• Often asymptomatic early, so screening/diagnosis pathways are heavily tested.
• Classic board traps:
  • Peripheral (posterior) prostate cancer vs transition zone BPH
  • PSA pitfalls (not cancer-specific)
  • Bone mets pattern and lab clues (osteoblastic lesions, ↑ ALP)

First Aid cross-reference: Reproductive → Prostate pathology; Oncology → tumor markers (PSA), metastasis patterns; Pharm → androgen deprivation therapy.

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Definition (Step-Ready)

Prostate cancer is usually an adenocarcinoma arising from glandular epithelium, most commonly in the peripheral/posterior zone of the prostate.

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Epidemiology & Risk Factors (High-Yield)

Big risk factors to memorize

• Age (strongest)
• Family history / genetics
  • BRCA2 (particularly high-yield association with aggressive disease)
  • HOXB13 (less commonly tested but real)
• African American ancestry: higher incidence and mortality
• Androgen exposure/signaling (conceptual driver; basis of therapy)

Protective-ish association (classic Step fact)

• 5-α reductase inhibitors (e.g., finasteride) reduce conversion of testosterone to DHT and can reduce prostate size; their relationship to cancer risk is nuanced, but Step questions mainly test their BPH role and sexual side effects.

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Pathophysiology: What’s Happening Under the Hood?

Androgens drive growth

• Prostate tissue growth is androgen-dependent, especially DHT, formed via 5-α reductase:
  • Testosterone \xrightarrow$$\text{5-}\alpha\text{ reductase}$${} DHT
• Cancer cells often remain androgen-sensitive initially → rationale for androgen deprivation therapy (ADT).

Why “peripheral zone” matters clinically

• Peripheral/posterior tumors are more likely to be felt on DRE (hard, irregular nodule).
• Transition zone enlargement is BPH → urinary symptoms early, but DRE feels “rubbery” and symmetric.

First Aid cross-reference: Prostate cancer classically in peripheral zone; BPH in transition zone.

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Pathology & Histology (What They Can Show You)

Gross / location

• Typically arises in posterior peripheral prostate.

Microscopy (board-style clues)

• Adenocarcinoma: infiltrative small glands
• Prominent nucleoli can be described
• Gleason grading (pattern-based histologic grading)
  • Higher Gleason score = worse prognosis (you don’t need to calculate intricate combos for Step 1, but know high score → aggressive)

Perineural invasion (common concept)

• Often mentioned in pathology reports and can be tested as a classic route of spread.

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Clinical Presentation: How It Shows Up on Exams

Early disease

• Often asymptomatic
• Detected via elevated PSA or abnormal DRE

Later disease (local effects)

• Urinary symptoms can occur, but this is a trick:
  • Prostate cancer is often peripheral → urinary obstruction tends to be later than in BPH.

Metastatic disease (very high-yield)

• Bone pain, especially back/hips
• Weight loss, fatigue
• Spinal cord compression signs (emergency)
• Bone metastases from prostate are classically osteoblastic.

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Screening & Diagnosis (The Step 1 Core Algorithm)

Two common screening tools

• PSA
• DRE

PSA: know what it is—and what it isn’t

• PSA = serine protease produced by prostate epithelium.
• PSA is not cancer-specific.
• PSA can be elevated in:
  • Prostate cancer
  • BPH
  • Prostatitis
  • Recent ejaculation
  • Recent instrumentation (e.g., catheterization, cystoscopy)

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Classic Step link: BPH and prostate cancer can both elevate PSA; cancer more concerning with abnormal DRE or concerning PSA kinetics.

What confirms the diagnosis?

• Transrectal ultrasound-guided biopsy (TRUS biopsy)
• Definitive diagnosis is histology, not PSA alone.

“Free PSA” concept (high yield nuance)

• Lower % free PSA is more suggestive of cancer.
• Higher % free PSA tends to suggest BPH.

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Staging & Spread (How It Travels)

Local invasion

• Seminal vesicles can be involved.

Lymphatic spread

• Typically to obturator and internal iliac nodes (pelvic nodes).

Hematogenous spread (board favorite)

• Bone metastases (especially axial skeleton: spine, pelvis)
• Produces osteoblastic (sclerotic) lesions

Lab tie-in

• Bone metastases → often ↑ alkaline phosphatase (ALP) (from osteoblastic activity)

Table: Prostate vs other bone metastasis patterns

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Treatment (Tie Therapy to Physiology)

Management depends on risk category and stage, but Step 1 focuses on the mechanisms and the “big levers.”

Localized disease

• Active surveillance (especially low-risk)
• Radical prostatectomy
• Radiation therapy (external beam or brachytherapy)

Advanced/metastatic disease: Androgen Deprivation Therapy (ADT)

Prostate cancer is often androgen-sensitive at first.

Core pharmacology to know (very testable):

• GnRH agonists: leuprolide, goserelin
  • Cause an initial testosterone flare then downregulate GnRH receptors → ↓ LH/FSH → ↓ testosterone
  • Co-administer antiandrogen early to prevent flare (high-yield clinical pearl)
• GnRH antagonists: degarelix (no initial flare)
• Antiandrogens: flutamide, bicalutamide, nilutamide
  • Block androgen receptor
• Androgen synthesis inhibitors: abiraterone (Step 2-ish, but may appear)

Chemo (advanced disease)

• Docetaxel and other regimens exist; less Step 1 emphasis than ADT mechanisms.

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Prognosis (What Predicts Outcomes?)

High-yield predictors:

• Stage (localized vs metastatic)
• Gleason score (higher = worse)
• PSA level (trend matters; not perfectly specific)

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Prostate Cancer vs BPH vs Prostatitis (Rapid Differentiation)

First Aid cross-reference: Classic “peripheral zone cancer vs transition zone BPH” is a staple.

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High-Yield Associations & Board Traps

1) PSA is not diagnostic

• Elevated PSA ≠ cancer.
• Definitive diagnosis requires biopsy.

2) Don’t confuse symptoms timing

• BPH causes early obstruction (transition zone).
• Prostate cancer often silent until later.

3) Bone metastasis pattern

• Prostate → osteoblastic lesions; think sclerotic on imaging and ↑ ALP.

4) DRE location clue

• Peripheral/posterior lesions are often palpable on DRE.

5) Hormone therapy logic

• ADT works because many tumors are initially androgen-dependent.
• GnRH agonists can cause a flare—pair with an antiandrogen.

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Quick USMLE-Style Vignettes (Pattern Recognition)

• Older man + hard, irregular prostate nodule on DRE + elevated PSA → suspect prostate cancer → confirm with biopsy.
• Bone pain + sclerotic lesions on imaging + elevated ALP + history of prostate cancer → osteoblastic bone metastases.
• Elevated PSA after UTI-like symptoms + tender prostate → prostatitis (don’t jump to cancer without the full picture).

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Rapid Review: The 10 Facts to Memorize

1. Prostate cancer is typically adenocarcinoma.
2. Most commonly arises in the peripheral/posterior prostate.
3. BPH arises in the transition zone.
4. PSA is a serine protease and is not cancer-specific.
5. Diagnosis is confirmed by biopsy.
6. Lower % free PSA suggests cancer (higher suggests BPH).
7. Metastasis commonly goes to bone (axial skeleton).
8. Bone mets are classically osteoblastic with ↑ ALP.
9. Androgen dependence explains use of ADT.
10. GnRH agonists can cause initial testosterone flare; prevent with antiandrogens.