This issue is devoted to focal therapies. Interest in focal therapy is fueled by the promise of cancer control with fewer side effects than are seen after radiation or radical prostatectomy. From the patient perspective, this is certainly an attractive option. As a result, we have seen the development of an increasing list of approaches to focal therapy.
There are a number of issues that make critical evaluation of the various focal therapies problematic. First, with the exception of a recent trial that involved laser, randomized clinical trials are absent. There is even a controversy about what is the best control group. The laser trial just mentioned used an active surveillance control group. The second approach would be to randomize against surgery or radiation therapy. The major problem is that such trials have proved nearly impossible to run because of poor accrual. For this reason, I suspect that focal therapies are most likely to find a clinical niche as an alternative or add-on to active surveillance.
Another issue is that we lack trials that randomize between two different focal therapies, so it is difficult to know what approach to recommend for a given patient. For example, cryosurgery and high intensity focused ultrasound (HIFU) have both been around for many years and have never been directly compared in a clinical trial.
In developing focal therapies, it is currently common practice to treat a group of patients with a new technology and then follow those patients over time. Results are reported after 1, 5, and 10 year follow-ups and comparisons made to historical results with radiation or radical prostatectomy. However, we have long known that such comparisons with historical data are often unreliable. As mentioned above, a better, more time efficient approach would be to test focal therapies as an alternate or addon to active surveillance rather than as an alternate to radical prostatectomy or radiation.
Charles E. Myers, Jr., MD