Standard guidelines for treating metastatic prostate cancer are based on conventional imaging (CT/bone scan). The panel argues that PSMA PET-positive biochemical recurrence represents a different, earlier disease state. This necessitates new treatment paradigms, like definitive therapy durations, not covered by current guidelines.

The advent of highly sensitive PSMA PET imaging identifies metastases in many patients previously considered to have only biochemical relapse (BCR). However, experts argue against a knee-jerk reaction to treat. Many of these patients, particularly those with slow PSA doubling times, can be safely observed, challenging the assumption that visible disease always requires immediate intervention.

A PSA doubling time of less than three months acts as a surrogate marker for death from prostate cancer. This powerful heuristic doesn't predict exact lifespan, but it signifies that the cancer's mortality risk has surpassed all other potential causes of death for that individual, signaling extreme high risk.

When PSA levels rise after initial treatments, patients face the difficult realization that their cancer is likely a chronic condition to be managed, not a disease to be cured. This existential moment requires a fundamental shift in their approach and expectations for the rest of their lives.

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.

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.

The NCI Working Group argues against equating PSMA PET-positive biochemically recurrent (BCR) prostate cancer with traditional metastatic disease. They propose the term "PSMA positive BCR" to emphasize that traditional prognostic factors still apply and the natural history is distinct and often more indolent.

The innovative Triple Switch trial treats all patients with a doublet therapy and then uses their PSA response at six months to guide further treatment. Patients whose PSA fails to reach a nadir are then randomized to receive docetaxel chemotherapy, testing a strategy of early intensification based on a real-time biological response rather than upfront risk stratification.

For high-risk biochemically recurrent prostate cancer, intermittent androgen deprivation therapy (ADT) is the standard of care, not continuous therapy. This approach significantly improves quality of life, bone health, and metabolic health while effectively delaying progression to metastatic disease for years. Continuous therapy is vehemently discouraged in this setting.