Loss of Heterozygosis on Interferon-Alpha Locus Is a Prognostic Indicator of BCG Response in Non-Muscle Invasive Bladder Cancer
G Nesi, T Cai, M Dal Canto, N Mondaini, M Piazzini, R Bartoletti. University of Florence, Florence, Italy
Background: Non-muscle invasive bladder carcinoma (NMIBC), treated by resection and intravesical administration of Bacillus Calmette Guerin (BCG), yields a remission rate that approaches 70%. We examined whether loss of heterozygosis (LOH) on interferon-alpha (IFN-α) locus can serve to predict response.
Design: A total of 117 consecutive subjects (77 patients affected with NMIBC and 40 controls) were selected. LOH on IFN-α locus (Chromosome 9) was assessed on blood and urine samples before transurethral resection (TUR). All patients underwent TUR and subsequent 6 weekly BCG instillations. Patients affected with NMIBC were assigned to group A (with LOH on IFN-α locus) and group B (without LOH on IFN-α locus). The main outcome parameters were time to first recurrence and recurrence rate. The relative data were compared with follow-up information.
Results: Out of the 77 patients with NMIBC, 39 (50.6%) showed at least one alteration on IFN-α locus (group A), with 38 (49.4%) showing no alteration (group B). Only 1 out of 40 controls exhibited LOH on IFN-α locus. At the end of follow-up, 13 patients in group A and 27 in group B were alive without recurrence. A significant difference between LOH on IFN-α and status at follow-up was found (p=0.003; dF01; LR=11.252). Kaplan-Meier analysis demonstrated a significant difference in terms of recurrence probability (response to BCG) and LOH on IFN-α (p=0.0001). At multivariate analysis, LOH on IFN-α locus (p=0.002) (LOH, HR 4.09 2.59–6.28, 95% CI), grade (p=0.03) (grade 3, HR 3.31 1.38–3.35, 95% CI) and the number of lesions (p=0.03) (≥3 lesions, HR 2.31 1.38–3.25, 95% CI) were identified as independent predictors of BCG response.
Conclusions: This study highlights the predictive value of LOH analysis on IFN-α in patients affected with NMIBC and treated by intravesical administration of BCG.
Category: Genitourinary (including renal tumors)
Wednesday, March 24, 2010 1:00 PM
Poster Session VI # 136, Wednesday Afternoon