Existing methods of selecting candidates for focal therapy leave much to be desired. Transrectal ultrasound with biopsy, as it is currently done, is a very poor way of detecting tumor foci, and radiographic imaging is not adequately sensitive, although its sensitivity is improving. “Nor can it tell us the grade of these small tumors,” Dr. Koch said.
Focal therapy has been suggested as an option for low-risk prostate cancer, but in Dr. Koch’s opinion, patients with these low-risk cancers should be put on active surveillance instead. Dr. Koch concluded that at this juncture, focal therapy has not been shown to effectively localize prostate cancer. “Are we ready to conduct a phase III trial with focal therapy? I would say no,” he said. Of course, “if payers decide to reimburse for focal therapy, it may very well become the leading treatment of low-risk prostate cancer.”
A major advance in prostate cancer treatment
Focal treatment of prostate cancer is definitely an idea whose time has come, Dr. Emberton told his audience. Prostate cancer is the only cancer for which the entire gland is removed or treated regardless of tumor location, he pointed out. But this approach has been abandoned in breast and kidney cancer. The same approach should be taken in prostate cancer as well, he said.
The wide array of treatment options available has given focal therapy a considerable boost, Dr. Emberton said.
“Technologies now exist that make focal treatment feasible. Cryosurgery, HIFU, photodynamic therapy, radiofrequency ablation, and brachytherapy can create localized necrosis within the prostate of a predetermined size in a relatively controlled manner,” he said.
While there may not be long-term data to support the use of these modalities in whole-gland therapy, all of these technologies are capable of destroying prostate tissue “with millimeter accuracy,” he said (Eur Urol 53:1194-1201, 2008).
Dr. Emberton acknowledged that focal therapy will never be suitable for all patients, just like partial nephrectomy is not suitable for all patients. He argued that it will be useful in men who put preserving genitourinary function at the top of their list.
“You can see here that having an option in the middle ground may serve the interests and address the utilities of a lot of patients we look after and treat,” he said.
The question that should be asked is, “In men with early prostate cancer, can focal or zonal therapy, vs standard therapy, active surveillance, or whole-gland radical therapy, confer improved tolerability, less toxicity, comparable or acceptable efficacy, and less cost?” he said.
Focal therapy represents a major advancement in prostate cancer treatment, Dr. Emberton said. The therapy is controversial now but so was lumpectomy for breast cancer and partial nephrectomy for kidney cancer at one time, he added.
Dr. Emberton acknowledged that long-term data on focal therapy are still needed. Nonetheless, its benefits are clear.
“Focal therapy virtually guarantees a man a normal genitourinary function by one to three months,” he said. “It is associated with the absence of clinically significant, clinically important, biologically important disease in all patients treated and evaluated to date, and it is associated with no evidence of disease recurrence.”
