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Comparative quantitative evaluation of the XIAP, survivin & Ki67 transcript levels in urine & tissue samples of bladder cancer patients. Woei-Yun Siow & Axel Meye & Oliver W. Hakenberg Juliane Schmidt & Susanne Füssel & Catharina Rippel. Introduction.
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Comparative quantitative evaluation of the XIAP, survivin & Ki67 transcript levels in urine & tissue samples of bladder cancer patients Woei-Yun Siow & Axel Meye & Oliver W. Hakenberg Juliane Schmidt & Susanne Füssel & Catharina Rippel
Introduction • Bladder cancer (BCa): 4th most common cancer in men & 9th leading cause of death worldwide • cystoscopy & urine cytology: current gold standards for diagnosis & surveillance of BCa • no ideal tumor marker for non-invasive diagnostic & surveillance at the moment
Objectives • to establish methods for quantitative transcript measurements in urine and tissue specimens (TUR-BT) • to determine suitability of transcript levels of different BCa-related genes (survivin, Ki67 and XIAP) in urine samples as diagnostic, surveillance and prognostic markers of BCa • to analyze marker expression in corresponding BCa tissue specimens in comparison to urine samples
BCa-related genes • survivin & XIAP: inhibitor of apoptosis proteins (IAP) • Ki67: proliferation marker, essential for cell cycle progression • selectively over-expressed in most human malignancies incl. BCa • association between over-expression and higher stage & grade and with unfavorable prognosis • suitable markers (tissue and urine specimens ) and therapeutic targets for BCa
Materials & Methods 1 • prospective study: February 2006 - January 2007 • inclusion criteria: • patients undergoing transurethral resection (TUR-BT) for newly diagnosed BCa, recurrent BCa & cystoscopically suspicious bladder lesions • exclusion criteria: • patients with PCa and non-urothelial tumors • controls • BPH patients • cystitis patients • healthy volunteers • BCa patients before cystectomy
Materials & Methods 2 • BCa patients • pre-operative urine sample • intra-operative tumor tissue & “normal appearing” bladder mucosa • post-operative urine sample (1 POD) • for every TUR-BT (prim./sec./ tert., 4-6 weeks) • same procedure for recurrences • controls • 1 urine sample
recurrence primary TUR-BT 4-6 Wochen recurrence secondary TUR-BT cystectomy 4-6 weeks tertiaryTUR-BT cystectomy Course of treatment for BCa patients
Materials & Methods 3 • preparation of cellular components from urine • isolation of total RNA and cDNA-synthesis • quantitative PCR for transcript levels of survivin, XIAP & Ki67 and the reference gene TBP in urine and tissue samples • correlation of the relative expression levels (internal normalization to TBP) of survivin, XIAP & Ki67 with clinico-pathological data
BCa patients (n=) • age (median) = 70 yrs. (34 – 93) • M:F = 63 : 43 (59,4% : 40,6%) • newly diagnosed : recurrence = 92 : 14 (86,8% : 13,2%) • PSA (median; 58 pts.) = 1,195 (0,16 – 33,91) • tumor stage: NT= kein Tumor nachweisbar pTa pT1 >pT1 • cis: 92 :14 (86,6% : 13,2%) Cis • pos. : neg. = 5 : 54 (8.5% : 91.5%) • All pts with cis harbour high grade (G2/ G3) disease as well. • tumor grade: NT LMP (low malginancy potential) • low grade • high grade
BCa patients 3 59 primary TUR 42 second op (33 sec TUR, 9 cystec) • 8 third op (6 tertiary TUR, 2 cystec) Controls
Results 1 • 2 reference genes tested: TBP better than HPRT • urine specimens: negative correlation between reference gene expression & urinary contamination by RBCs, WBCs & bacteria many samples with negative reference gene results (e.g. pts with infection or hematuria or post-TUR urines) • tissue specimens: less samples with negative reference gene results • target validation in tissue specimens, comparison Tu Tf • target evaluation in urine specimens with regard to BCa diagnosis
Tumor markers in unpaired tissue specimens Median values presented.
Tumor markers in paired tissue specimens Median values presented.
Tumor markers in urine specimens of BCa patients & controls For healthy controls the absent values were substituted by zero Median values presented.
Tumor markers in urine vs BCa stage Median values presented.
Tumor markers in urine vs BCa grade Median values presented.
Offene Fragen/Überlegungen 1 • Abfall der Tumormarker nach der primären TUR-BT? Korrelation mit histologischem Befund? • Ausschlusskriterium HWI: Bakterienzahl oder positive Urinkultur? • Möglicherweise Verfälschung der Werte durch hohe Leukozytenzahl • Kontrolle der vermeintlich Gesunden
Offene Fragen/Überlegungen 2 • Ausweitung der gesunden Kontrollgruppe: z.B. Zystitis-Patienten nach Abschluss der Therapie? • Statistische Signifikanz: möglich durch Kombination der Tumormarker ? • Ausweitung der Tumorgene sinnvoll (z.B. hTERT )? • Berechnung Sensitivität/Spezifität erst bei größeren Fallzahlen sinnvoll, dann Vergleich mit Urinzytologie
Offene Fragen/Überlegungen 3 • Geschlechtsspezifischer Test? ( Probleme durch Einfluss von BPH ) • Korrelation Tumormarker im Urin und korrespondierenden Gewebe • Postoperativer Urin oft nicht auswertbar (Blut, Kreisspülung usw.) Stopp der Sammlung ? • Stopp der Gewebesammlung oder Fortführung für andere Projekte ?
Offene Fragen/Überlegungen 4 • Urinsammlung vor Cystektomie ? • Erhebung der klinischen Daten vollständig? • Gezielte Nachbeobachtung von Patienten ohne histologischen Tumornachweis?