New molecular markers for detection of PC still far removed from clinical standard
Hamburg, 22 September 2006. Prostate cancer and the search for new biomarkers was the main focus of this year's "Science around Thirty" programme at the German Urological Association (DGU) Annual Congress, which allows five outstanding urological residents not older than 35 to present a review of their research during a forum session. Each of these five residents receives a 1,000 Euro award; the best scientific presentation is awarded with an additional 1,000 Euro.
Dr. Jorn Kamradt from Homburg/Saar received the presentation award for his review on "The Genome of Prostate Cancer in the Spotlight: The Search for New Biomarkers". Dr. Kamradt's work aims at developing a genomic analysis in order to identify target genes that will help improve our understanding of the molecular pathogenesis of prostate cancer. Prostate cancer is very heterogeneous - from slow-growing tumours with no or late metastases to fast-growing, aggressively tumours with high potential of metastases and early androgen insensitivity. Today, therapy consequently ranges from watchful waiting to radical prostatectomy and radiotherapy, sometimes combined with hormone treatment dependent on the clinical risk assessment of the patient. Dr. Kamradt's goal is to find better prognostic biomarkers for the tumour's biologic behaviour thus allowing a finer adjustment of the therapy.
Also part of the programme were Dr. Thomas Steuber from Hamburg and Dr. Carsten Stephan from Berlin.
Dr. Steuber attempts to improve early detection and prognostic prediction of prostate cancer by integrating new molecular markers in his nomogram models. These nomograms are helpful to predict a positive biopsy, the outcome of local staging and the risk of progression following local therapies such as radical prostatectomy. His candidate markers are receptor fragments of the plasminogen-urokinase-receptor and iso-forms of free PSA as well as of human glandular kallikrein 2 (HK2). These markers are scrutinized and evaluated statistically to qualify and objectify on the one hand the actual increment in predictive accuracy and on the other hand the actual information obtained by the particular marker.
In terms of a possible clinical application Dr. Steuber sees considerable improvement in the prediction of biochemical recurrences following radical prostatectomy provided by HK2. First results on this marker are encouraging but require further external validation before developing a trusted tool for clinical diagnosis. Respective multi-variable marker evaluation studies are underway that use retrospective serum samples from patients treated for prostate cancer in the early 90s. Steuber admits that prognostic information on tumours provided by established markers such as PSA or the biopsy Gleason grade is already fairly good. However, different views among institutions on these criteria cause differences in interpretation and treatment. Thus new and generally accepted biomarkers would facilitate a reproducible assessment of prostate cancer treatment and patient care all over the world.
In his search for new molecular markers for the detection of prostate cancer, Dr. Stephan investigates the necessity of the initial biopsy. Models such as logistic regression and an artificial neural network in particular are used to predict positive or negative biopsy outcome. Therefore HK2, HK11 or - from prostate cancer tissue - HK15 or markers like cPSA or ProPSA are incorporated in the network to improve prediction of positive biopsy results. Although the network itself has been used in clinical routine since 2002, Dr. Stephan does not expect HK2 or ProPSA itself to be included in clinical practice in the foreseeable future. Acknowledging the significance and the uniqueness of PSA, he states that a tumour marker similar to PSA clearly is an unmet need for the diagnosis and follow up of colorectal or gynaecological tumours.
For more information, please contact:
European Association of Urology
Ms. Lindy Brouwer
Communication Officer
T: +31 26 3890139
E: communicationoffice(at)uroweb.org
