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.

While many clinical trials haven't officially counted PSMA-PET only disease as metastatic, clinicians have latitude. If a PSMA-PET scan reveals aggressive, multifocal disease, especially with a rapidly rising PSA, it should be treated as incurable metastatic cancer, justifying the initiation of systemic therapy.

In metastatic hormone-sensitive prostate cancer, patient outcomes vary dramatically. Triplet therapy is the default only for the highest-risk group: patients with de novo, high-volume disease, whose median survival on ADT alone is just three years. For all other patients, including those with low-volume or metachronous disease, doublet therapy is the standard.

While the landmark EMBARK study enrolled patients with no metastatic disease on conventional imaging (CT/bone scan), a similar population scanned with advanced PSMA PET imaging showed 84% had M1 disease. This suggests that treatments for this population are effective against micrometastases not visible on older scans, blurring the lines between localized and metastatic states.

An expert argues the path to curing metastatic cancer may mirror pediatric ALL's history: combining all highly active drugs upfront. Instead of sequencing treatments after failure, the focus should be on powerful initial regimens that eradicate cancer, even if it means higher initial toxicity.

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.

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.

The definition of high-volume disease, a key factor in chemotherapy decisions for prostate cancer, has changed across major trials like CHARTERED and STAMPEDE. This evolution, including variations in bone metastases counts and inclusion of Gleason score, complicates cross-trial analysis and highlights its weakness as a surrogate for true disease biology.

The clinical definition of "non-metastatic" prostate cancer is based on conventional imaging like CT and bone scans. However, with advanced PET scanning, it's clear these cases are biologically micro-metastatic. This discrepancy is crucial as clinical trial data for this stage is based on the older, less sensitive imaging standards.