Metastatic castration-resistant prostate cancer (mCRPC) is an advanced stage of prostate cancer in which the disease has spread to distant sites (e.g., bones, lymph nodes, or organs) and continues to progress despite low testosterone levels achieved through androgen deprivation therapy (ADT).

By definition, these cancers no longer respond to standard hormone therapy but may still be sensitive to other treatments that block androgen signaling more effectively or work through different mechanisms. mCRPC typically requires second-line therapies, such as androgen receptor inhibitors (enzalutamide, apalutamide), androgen synthesis inhibitors (abiraterone + prednisone), chemotherapy (docetaxel, cabazitaxel), immunotherapy, or targeted agents (e.g., PARP inhibitors for patients with BRCA mutations).

This stage is associated with a higher symptom burden and requires a personalized, multimodal approach to manage disease progression and maintain quality of life.