[841] Loss of Heterozygosity on Chromosome 18 in Patients with Non-Muscle Invasive Bladder Cancer: Results from a Prospective Study

G Nesi, T Cai, M Dal Canto, N Mondaini, M Piazzini, R Bartoletti. University of Florence, Florence, Italy

Background: Somatic alterations on chromosome (Chr) 18q21-23, such as loss of heterozygosity (LOH), have been indicated as a critical step in bladder carcinogenesis. The aim of this study was to evaluate the prognostic role of LOH on Chr 18q21-23 in patients affected by low-grade, non-muscle invasive bladder cancer (NMIBC).
Design: A group of 108 consecutive patients (65 affected by low-risk NMIBC and 43 controls) were selected for this prospective study. LOH on Chr 18 was assessed on the blood/urine pair. The primers used were D18S51, MBP LW and MBP H. The data obtained were compared with follow-up information. Results were also analysed by using artificial neural networks (ANN).
Results: Out of the 65 patients with NMIBC, 38 (58.4%) showed at least one alteration on Chr 18, while 27 (41.6%) showed no alteration. In the control group, only 2 out of 43 subjects showed LOH on Chr 18. At the end of follow-up, 29 patients were alive without recurrence, while 36 had at least one recurrence. A significant correlation between LOH on Chr 18 and status at follow-up was found (p=0.022). The Kaplan-Meier curves demonstrated a significant correlation between recurrence-free status and LOH on Chr 18 (p=0.0003). At multivariate analysis, LOH on Chr 18 (p=0.002) and the number of lesions (p=0.03) were identified as independent predictors of recurrence-free probability. ANN analysis confirmed the results from multivariate analysis.
Conclusions: This study highlights the role of LOH analysis on Chr 18 in improving recurrence prediction in patients affected by low-grade NMIBC.
Category: Genitourinary (including renal tumors)

Tuesday, March 10, 2009 1:00 PM

Poster Session IV # 149, Tuesday Afternoon