Benchmarks for success in focal therapy of prostate cancer: cure or control?

BACKGROUND: The place of focal therapy in prostate cancer management requires further evaluation within randomized comparative clinical trials.
METHODS: This review article discusses the place of focal therapy and asks whether it is an alternative to active surveillance or radical therapy. This question therefore is at the heart of whether this proposed paradigm shift should be delivered with the intent of cure or cancer control.
RESULTS: For such trials to report on outcomes that have meaningful utility in the clinic, it is necessary to discuss whether focal ablation should be delivered with intent to eradicate all cancer foci ('cure') or ablate all clinically significant lesions with surveillance of all remaining tissue (benign or harboring clinically insignificant cancer). While the former will inevitably mean that fewer men will be appropriate for focal therapy were it to become standard care, it is the safest approach. The latter strategy will open focal therapy to the majority of men with low- to intermediate-risk disease with the potential of offering a treatment strategy that treats important cancer while preserving function with a high degree of probability.
CONCLUSION: A pragmatic randomized controlled clinical in which focal therapy is randomized against standard of care may be feasible. The pragmatic nature of such a trial would allow eligibility criteria, localization of cancer to reflect local practice (novel imaging and transrectal biopsy or template prostate mapping), and the focal intervention (ablative modality, intent to ablate all cancer foci or all clinically significant foci) to be kept broad to reflect clinical practice. Further, it would satisfy individual equipoise by allowing either active surveillance or radical therapy in the standard care arm, to be decided on by patient and physician.