CRPC Definition — SCE Medical Oncology MCQ

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EasyUrological CancersCRPC DefinitionSCE Medical Oncology

A 70-year-old man with metastatic prostate cancer has rising PSA despite ADT. His testosterone level is 0.3 nmol/L (castrate level <1.7 nmol/L). This confirms the diagnosis of CRPC. What defines castration-resistant prostate cancer?

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Correct answer: D — Rising PSA while testosterone is at castrate levels (<1.7 nmol/L or <50 ng/dL) — reflecting androgen-receptor pathway activity independent of testicular androgens

CRPC is defined as disease progression (rising PSA ≥2 ng/mL with 25% rise over nadir, OR radiographic progression) despite castrate testosterone levels (<1.7 nmol/L / <50 ng/dL). CRPC develops through multiple mechanisms: AR amplification, AR splice variants (AR-V7), intratumoral androgen synthesis, AR mutations, and AR-independent pathways. ADT must be continued throughout CRPC treatment (maintaining castrate testosterone) as most CRPC cells retain some androgen sensitivity.

Reference: ESMO 2024 Prostate Cancer; NICE NG131; Scher et al JCO 2008 PCWG2 criteria