Limitations of focal therapy in prostate cancer treatment
Monday, 2 February 2009- At the 6th European Society of Oncological Urology (ESOU) Meeting held recently in Istanbul, Turkey, Prof. Alexandre Zlotta (Toronto, Canada) raised his concerns over the limitations of focal therapy, saying that current technology in detecting prostate cancer (PCa) cells is not yet well advanced that it could lead to a wider use of focal therapy for early PCa.
"Our main limitation with the concept of focal therapy in prostate cancer is the ability to detect and assess the biological threat," said Zlotta in response to a lecture by Prof. Jean de la Rosette who argued and cited the potentials of focal therapy for early prostate cancer.
"We unfortunately do not have yet a technology that can accurately detect and map prostate cancer cells within the gland and therefore focal therapy cannot be considered but investigational at the present time," he added.
Zlotta pointed out that although candidates for focal therapy exist among men undergoing radical prostatectomy (RP), these patients represent "…a small minority and there is no way to reliably predict who they are."
For patients faced with a choice between aggressive local intervention such as radiation or surgery, on one hand, and active surveillance for localised PCa, on the other, focal therapy has gained some interest as an attractive alternative. Focal therapy could include subtotal gland abalation, hemiablative therapy (HAT), or lesion ablative therapy.
"The challenge in pursuing any of these focal therapy modalities lies in appropriately selecting the ideal candidates by defining the disease site and extent," noted Zlotta.
At present four leading technologies are being used for focal therapy: high-intensity focused ultrasound (HIFU), cryotherapy, radio frequency ablation (RFA), and photodynamic therapy (PDT).
Zlotta said that despite the emergence of contemporary diagnostic biopsy strategies and imaging tools that have led to improvements in tumour characterisation and risk-stratification, these "…are far from perfect."
"With newer imaging technology and more thorough biopsy samples, preoperative estimates of final pathology are becoming more accurate but there are concerns about recent reports of high rates of bilateral cancer among men with seemingly focal disease," said Zlotta.
He argued that most men with even a favourable risk prostate cancer have bilateral disease and there is "…no way to tell a man with unilateral disease from one with bilateral disease a priori."