Focal therapy for localized prostate cancer: a critical appraisal of rationale and modalities.
OBJECTIVE
Based on contemporary epidemiological and pathological characteristics of prostate cancer we explain the rationale for and concerns about focal therapy for low risk prostate cancer, review potential methods of delivery and propose study design parameters.


METHODS
Articles regarding the epidemiology, diagnosis, imaging, treatment and pathology of localized prostate cancer were reviewed with a particular emphasis on technologies applicable for focal therapy, defined as targeted ablation of a limited area of the prostate expected to contain the dominant or only focus of cancer. A consensus summary was constructed by a multidisciplinary international task force of prostate cancer experts, forming the basis of the current review.


RESULTS
In regions with a high prevalence of prostate specific antigen screening the over detection and subsequent overtreatment of prostate cancer is common. The incidence of unifocal cancers in radical prostatectomy specimens is 13% to 38%. In many others there is an index lesion with secondary foci containing pathological features similar to those found incidentally at autopsy. Because biopsy strategies and imaging techniques can provide more precise tumor localization and characterization, there is growing interest in focal therapy targeting unifocal or biologically unifocal tumors. The major arguments against focal therapy are multifocality, limited accuracy of staging, the unpredictable aggressiveness of secondary foci and the lack of established technology for focal ablation. Emerging technologies with the potential for focal therapy include high intensity focused ultrasound, cryotherapy, radio frequency ablation and photodynamic therapy.


CONCLUSIONS
Early detection of prostate cancer has led to concerns that while many cancers now diagnosed pose too little a threat for radical therapy, many men are reluctant to accept watchful waiting or active surveillance. Several emerging technologies seem capable of focal destruction of prostate tissue with minimal morbidity. We encourage the investigation of focal therapy in select men with low risk prostate cancer in prospective clinical trials that carefully document safety, functional outcomes and cancer control.
Eggener
Scott E
SE
Scardino
Peter T
PT
Carroll
Peter R
PR
Zelefsky
Michael J
MJ
Sartor
Oliver
O
Hricak
Hedvig
H
Wheeler
Thomas M
TM
Fine
Samson W
SW
Trachtenberg
John
J
Rubin
Mark A
MA
Ohori
Mak
M
Kuroiwa
Kentaro
K
Rossignol
Michel
M
Abenhaim
Lucien
L
D000726:Androgen Antagonists / Q000627:therapeutic use; D001707:Biopsy, Needle; D003452:Cryosurgery / Q000379:methods; D006801:Humans; D008297:Male; D009361:Neoplasm Invasiveness / Q000473:pathology*; D009367:Neoplasm Staging; D010778:Photochemotherapy / Q000379:methods; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy / Q000379:methods; D011471:Prostatic Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000628:therapy*; D020266:Radiotherapy, Conformal / Q000379:methods; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D036761:Ultrasound, High-Intensity Focused, Transrectal / Q000379:methods
D000726:Androgen Antagonists; D017430:Prostate-Specific Antigen