BERKELEY, CA (UroToday.com) - Focal therapy in prostate cancer is an individualized therapy that precisely ablates known disease while preserving functionality, attempting to minimize lifetime morbidity without compromising life expectancy.
Although still limited, the evidence suggests that focal therapy may be an alternative treatment, midway between expectant management and radical treatment.
HIFU belongs to the group of minimally invasive therapy techniques that have been assessed as suitable for focal therapy. The selection of patients remains a controversial issue, where potential tumor multifocality and exact determination of index lesions remain the essential issues to assess through further improved imaging and prostatic biopsies. The objective evaluation of outcomes involves a multivariable assessment of biochemical values, imaging and biopsies (Figure 1).
Muto et al.(1) compared focal therapy with whole-gland ablation in a series of 70 patients. Of 29 patients with unilateral disease, focal therapy involved ablation of the total peripheral zone and a half portion of transitional zone, and resulted in a 77% negative biopsy rate at 12 months. Of the remaining 41 patients with bilateral disease, whole-gland ablation resulted in an 84% negative biopsy rate at 12 months. Two-year biochemical recurrence-free survival rates were 91% and 50% for low and intermediate risk groups who were undergoing whole-gland ablation, compared with 83% and 54% respectively for the focal therapy equivalents. Morbidity with the two forms of HIFU was comparable. Focal therapy has to be clearly defined as to whether it should be organ and/or disease related.
A focal approach to prostate cancer, conducted over ten years ago at The Montsouris Institute (2) and based on a sextant biopsy diagnosis, resulted in outcomes similar to patients that were treated in the same period with a whole-gland approach. This further expands the discussion on focal therapy, because these men with organ-confined, low to moderate risk prostate cancer were offered ablation of only half of their prostates and, despite that, experienced acceptable freedom from disease progression. Twelve patients with a mean age of 70 years were treated (PSA ≤10ng/ml, ≤3 positive biopsies with only 1 lobe involved, clinical stage ≤T2a, Gleason score ≤7 (3+4), negative CT and bone scan). Hemi-ablation of the prostate was performed with the Ablatherm® device, and follow-up biopsies were performed at 1 year. Median follow-up of these patients was 10 years. Follow-up prostate biopsies were negative in 11/12 patients (91%). Overall survival was 83% (10/12) and cancer-specific survival was 100% at 10 years.
The University College of London conducted a phase II trial with HIFU, employing the Sonoblate 500 device in over 80 patients with low to intermediate risk prostate cancer. The study included different ablation approaches, such as hemiablation, focal ablation and index lesion ablation. Patients were preoperatively selected based on Multifunctional MRI and template prostate-mapping biopsies. This study demonstrated 95% preservation of genitourinary function and 90% negative biopsy rates at 6 months after focal therapy with HIFU.(3)
HIFU technology remains a viable treatment option in the field of prostatic carcinoma, keeping in mind that for a focal treatment approach, careful selection of patients should always be employed. This field has progressed rapidly, and this progress will provide the expected data, derived from clinical trials, on which we can further base our enthusiasm for focal therapy.
Figure 1: Focal therapy in LPCa
- Muto S, Yoshii T, Saito K, et al. Focal therapy with high-intensity-focused ultrasound in the treatment of localized prostate cancer. Jpn J Clin Oncol. 2008;38(3):192-9.
- El Fegoun AB, Barret E, Prapotnich D, Soon S, Cathelineau X, Rozet F, Galiano M, Sanchez-Salas R, Vallancien G. Focal therapy with high-intensity focused ultrasound for prostate cancer in the elderly. A feasibility study with 10 years follow-up. Int Braz J Urol. 2011 Mar-Apr;37(2):213-9
- Ahmed HU, Moore C, Lecornet E, Emberton M. Focal therapy in prostate cancer: determinants of success and failure. J Endourol. 2010 May;24(5):819-25.
Eric Barret, MD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.