Current status of focal primary therapy for prostate cancer

Abstract

The focal therapy session was moderated by Dr. Samir Taneja and addressed the central question: Why focal therapy for prostate cancer? The primary reasoning for most practitioners of focal therapy centers on the acceptance that there is established overtreatment of clinically localized prostate cancer. The important issues surrounding focal therapy include, (1) patient selection (e.g., unifocal vs. multifocal disease and low-risk disease, (2) method of focal therapy (e.g., imagevs. biopsy-guided therapy, (3) outcomes (e.g., how do we determine cure vs. recurrence The goals of focal therapy are variable and should be considered before embarking on a focal therapy program. These goals include (1) curative intent, (2) prolongation of natural history, and (3) tumor debulking. It has been shown by Mark Emberton and others that among men who undergo radical prostatectomy, only approximately 20% have unifocal disease. Therefore, relatively few men would gain completely curative benefit from focal therapy. Additionally, the dominant Gleason score is found in index lesion. Similarly, secondary and tertiary lesions are rarely the site of extracapsular extension (ECE) or recurrence. Lastly, there is data to support that metastatic disease is derived from 1 clonal phenotype. Dr. John Trachtenberg from Toronto then described image-guided, robot-assisted focal laser therapy. The goals of this therapy are to balance cancer control and maintenance of quality of life. This technology utilizes MR guidance with real-time thermal imaging of the target lesion, which allows for visualization of target destruction, while also monitoring for preservation of normal structures. This visualization allows for detection of prostate motion due to various external factors. Additionally, the energy delivery can be tightly controlled, delivered to within 1 mm of the target, and is FDA approved. In a pilot trial of five subjects, the MR-guided laser therapy was performed followed by radical prostatectomy. The histology of the treated pros-