Focal therapy for localized prostate cancer: a phase I/II trial

Men with localized prostate cancer currently face a number of treatment options that treat the entire prostate. These can cause significant sexual and urinary side effects. Focal therapy offers a novel strategy that targets the cancer rather than the prostate in an attempt to preserve tissue and function.

A prospective, ethics committee approved trial was conducted to determine the side effects of focal therapy using high intensity focused ultrasound. Multiparametric magnetic resonance imaging (T2-weighted, dynamic contrast enhanced, diffusion-weighted) and template transperineal prostate mapping biopsies were used to identify unilateral disease. Genitourinary side effects and quality of life outcomes were assessed using validated questionnaires. Posttreatment biopsies were performed at 6 months and followup was completed to 12 months.

A total of 20 men underwent high intensity focused ultrasound hemiablation. Mean age was 60.4 years (SD 5.4, range 50 to 70) with mean prostate specific antigen 7.3 ng/ml (SD 2.8, range 3.4 to 11.8). Of the men 25% had low risk and 75% had intermediate risk cancer. Return of erections sufficient for penetrative sex occurred in 95% of men (19 of 20). In addition, 90% of men (18 of 20) were pad-free, leak-free continent while 95% were pad-free. Mean prostate specific antigen decreased 80% to 1.5 ng/ml (SD 1.3) at 12 months. Of the men 89% (17 of 19, 1 refused biopsy) had no histological evidence of any cancer, and none had histological evidence of high volume or Gleason 7 or greater cancer in the treated lobe. In addition, 89% of men achieved the trifecta status of pad-free, leak-free continence, erections sufficient for intercourse and cancer control at 12 months.

Our results appear sufficiently promising to support the further evaluation of focal therapy as a strategy to decrease some of the harms and costs associated with standard whole gland treatments.