Simultaneous Proteomic and Genomic Analysis of Primary Ta Urothelial Cell Carcinomas for the Prediction of Tumor Recurrence

Abstract

Background: The prediction of tumor recurrence in patients with Ta urothelial cell carcinoma is inaccurate and new prognostic markers are desirable. Materials and Methods: Surface-enhanced laser-desorption ionization time-of-flight mass spectrometry (SELDI-TOF MS) was performed on 33 primary Ta tumors (16 and 17 tumors were from patients with long and short recurrence-free periods, respectively) and data were compared to previously obtained mRNA expression profiles of 49 genes. Results: The intensities of a protein peak at m/z 33331 varied most significantly between the two patient groups (p=0.0048). This was comparable to survivin, whose mRNA expression differed most significantly (p=0.0042) of the 49 genes. ROC analysis revealed an area under the curve for protein peak 33331 and survivin of 0.78 (95% CI, 0.62-0.94) and 0.79 (95% CI, 0.63-0.94), respectively. Protein peak 33331 and survivin identified 3 (17%) and 8 (47%) patients with a recurrence-free period of at least 4 years, respectively, without generating false-negatives. Conclusion: These findings indicate that SELDI-TOF MS and real-time Q-PCR analysis on the same tissue can result in the identification of markers with comparable differential expression. Such combined analyses may yield combinations of several markers that might improve disease prognosis.