MP02-12 PROSTATE-SPECIFIC EXTRACELLULAR VESICLES AS A NOVEL BIOMARKER IN HUMAN PROSTATE CANCER

INTRODUCTION AND OBJECTIVES: Cancer detection using sniffer dogs is a potential technology for clinical use and research. Here we evaluate the ability of highly-trained dogs’ olfactory system to detect biochemical recurrence (BCR) in men after undergoing radical prostatectomy for prostate cancer (PCa). METHODS: One hundred-fourteen consecutive men with clinical localized PCa undergoing radical prostatectomy between November 2011 and May 2013 were investigated. For each patient urine and serum samples were collected prior to radical prostatectomy, forty-five days and every six months during the successive follow-up (mean: 28 months; median: 28 months; range 19-37 months). Two dogs were trained to sit when they detected PCa specific volatile organic compounds (VOCs) in the urine samples. RESULTS: Preoperatively, both dogs were able to detect PCa specific VOC’s in the urine samples of men with PCa with 100% accuracy. Forty-five days post-radical prostatectomy, 104 (91.2%) patients had a serum prostate-specific antigen (PSA) levels 0.01 but 1 ng/ml. Forty-five days following surgery, neither dog detected prostate cancer specific VOC’s in the urine samples of the 104 men with a serum PSA level 0.01ng/ml and 1ng/ml (i.e. persistent disease). During the successive follow up 9 of 110 patients (8.1%) had BCR. Both dogs were able to detect PCa VOC’s in the urine samples of 7 of these 9 patients (77.7%). CONCLUSIONS: Highly trained dogs are able to detect BCR in men who have previously undergone radical prostatectomy alone for PCa. Our understanding of the use of the canine olfactory system in PCa detection continues to evolve