SAN DIEGO, CA USA (UroToday.com) - Revisiting a technology that was believed to be of little utility in prostate cancer, Dr. Annie-Claude Blouin and colleagues from Quebec evaluated the utility of FDG-PET/CT in staging high-risk prostate cancer.
Recent literature from in vitro models has shown overexpression of glucose metabolism enzymes in high Gleason sum prostate cancer. Taking the bench to the bedside, the authors evaluated FDG-PET/CT in 54 patients with Gleason ≥ 8 prostate cancer prior to local therapy. At the time of biopsy, median PSA was 7.5. Increased FDG uptake was found in the prostate, lymph nodes (LN), and bones of 44, 15 and 6% of patients, respectively. In those undergoing radical prostatectomy, positive predictive values were 100% for LN metastasis. Pathologic downgrading to Gleason ≤ 7 occurred in 72.4% vs. 18.4% in patients without and with FDG uptake in the prostate (p=0.0001). None of the patients downstaged to Gleason 6 or (3+4) 7 at pathology had an increased FDG uptake.
The authors conclude that FDG-PET/CT is highly specific for LN metastasis and may identify intraprostatic pathological downstaging in biologically high-risk patients, identifying a possible prognostic and staging role for FDG-PET/CT in high-risk prostate cancers imaged before primary therapies.
The session moderator, John Davis, MD, from MD Anderson Cancer Center, was particularly excited about the possibility of a technology that is already widely available to assist clinicians in more accurately staging prostate cancer. One question posed was whether this technology could be applicable for patients undergoing active surveillance to rule out occult high-grade disease within the prostate. The authors noted this will need to be evaluated going forward.
Presented by Annie-Claude Blouin, Goran Rimac, F. Bouchard; Claude Lemay, Vincent Fradet, A. Caron, Yves Fradet, Louis Lacombe, Thierry Dujardin, Rabi Tigert, Jean-Mathieu Beauregard, and F. Pouliot at the American Urological Association (AUA) Annual Meeting - May 4 - 8, 2013 - San Diego Convention Center - San Diego, California USA
Reported for UroToday.com by Anthony T. Corcoran, MD
