In neoadjuvant settings, ctDNA monitoring allows for real-time therapy adjustment. Data from the iSpy platform shows 80% of hormone-positive patients clear ctDNA with half the chemotherapy, enabling de-escalation, while the remaining 20% can be identified for escalated treatment.

After years of successfully intensifying hormonal therapy, the focus in prostate cancer is shifting toward de-intensification. Researchers are exploring intermittent therapy for top responders and developing non-hormonal approaches like radioligands to spare patients the chronic, life-altering side effects of permanent castration.

The NCI working group asserts that PSA doubling time, especially a rate under six months, remains the key indicator of high-risk biochemically recurrent (BCR) prostate cancer. This biological marker of aggressiveness is considered more prognostically significant than the presence of lesions on a highly sensitive PSMA PET scan.

Major trials in prostate (PEACE-2), bladder (Keynote B15), and kidney cancer (LITESPARK-022) showcase a common strategy: moving potent systemic therapies into earlier, curative-intent settings. This approach of using the best drugs sooner aims to improve long-term outcomes, though it also raises questions about toxicity and overtreatment.

For patients with oligometastatic disease who achieve a deep PSA response (e.g., to zero), oncologists consider finite treatment durations (e.g., 18-24 months) followed by observation. This "do less harm" approach challenges the standard of continuous therapy until progression, aiming for long-term treatment-free intervals.

Intensive treatments like ADT plus an ARPI can suppress a patient's PSA so effectively that it becomes an unreliable marker of disease status. Patients may show radiographic progression on scans even while their PSA remains low and they feel clinically well. This discordance necessitates periodic imaging to avoid missing actual disease progression.

Experts believe molecular tests like Decipher and PTEN status are superior to simply counting bone lesions for guiding treatment. While not yet standard practice for all decisions, this represents a significant shift towards using underlying tumor biology to determine therapy, like adding docetaxel.

For patients with conventionally negative imaging but positive PSMA PET scans (oligometastatic disease), continuous intensified therapy may be overtreatment. A new paradigm involves metastasis-directed therapy followed by a short course of escalated treatment, then stopping to observe. This "time-limited" approach balances efficacy with reducing long-term treatment burden.

A key lesson in bladder cancer is that patient attrition is rapid between lines of therapy; many who relapse from localized disease never receive effective later-line treatments. This reality provides a strong rationale for moving the most effective therapies, like EV-pembrolizumab, to earlier settings to maximize the number of patients who can benefit.