A meta-analysis of six trials (Poseidon) found no overall survival benefit from adding long-course (24 months) hormone therapy to post-operative radiotherapy. It suggests that a shorter course of 4-6 months is adequate for most men, marking a significant shift towards treatment de-escalation to reduce long-term toxicity without compromising efficacy in this specific setting.

The EMBARK trial showed that enzalutamide monotherapy was superior to standard ADT monotherapy for metastasis-free survival. This suggests potent AR antagonism may be a more effective strategy than simply depleting the testosterone ligand, challenging the long-held dogma of ADT being the fundamental building block for systemic prostate cancer therapy.

The term "hormone resistance" was misleading. Researchers discovered that even in a castrate state, prostate cancer tumors produce their own testosterone locally. This maintained androgen receptor signaling, proving the disease was still "androgen addicted" and opening the door for new targeted therapies.

New guidelines from an international working group are replacing patient-insensitive terms like "castration-resistant" with "Androgen Pathway Modulator (APM) resistant/naive." This modernizes language to encompass a broader range of therapies and improve patient communication, while also incorporating sensitive imaging like PSMA PET.

The oral GnRH antagonist Relagolix allows for much quicker testosterone recovery (1-2 months vs. 3-6 for leuprolide). While beneficial in curative-intent settings, this rapid recovery is a double-edged sword that could shorten the "off-therapy" period during intermittent treatment for metastatic disease.

The term "APMR" (Androgen Pathway Modulator Resistant) is being adopted over "CRPC." This new terminology is more scientifically accurate for modern hormonal therapies and uses more patient-friendly language by removing the anxiety-inducing word "castration."

PCWG4 replaces terms like "castration-resistant" with "Androgen Pathway Modulation (APM) resistant." This change is driven by patient feedback finding the term "castration" insensitive and by the need for language that reflects modern treatments that don't always involve medical or surgical castration.

Counterintuitively, administering super-physiologic levels of testosterone can induce responses in certain castration-resistant prostate cancers. This strategy, called Bipolar Androgen Therapy, exploits the tumor's overexpressed receptors, turning a growth signal into a therapeutic vulnerability, though it remains a risky approach.

The IMbark trial demonstrated that an ARPI (enzalutamide), either alone or with ADT, outperformed ADT monotherapy in high-risk patients. This pivotal finding raises the question of whether giving ADT alone in any setting, such as with radiation for localized disease, is now an outdated and inferior approach.