Differential genomic profiles of tumor-involved and tumor-free sentinel lymph nodes in patients with melanoma.

9043 Background: For clinical stage I and II node negative melanoma the histologic status of the sentinel lymph node (SLN) is the most significant predictor of survival. Molecular characterization of node positive and node negative SLNs through gene expression profiling may improve the understanding of the molecular mechanisms of metastasis and identify specific gene signatures for SLN+/SLN- that correlate with clinical outcome. Methods: We characterized 15 SLN+ and 15 SLN- melanoma patients (T3a/b, T4a/b) who underwent SLN dissection for routine staging using transcriptome profiling analysis on 5μ sections of fresh LN samples. The primary endpoint was mRNA expression profiling using the U133A 2.0 Affymetrix gene chips. Significance Analysis of Microarrays v.4 was used to perform non-parametric analysis and statistical comparison for each transcript corrected for false discovery rate (q value) to control for type 1 errors arising from multiple tests. Pathway analysis was performed using Ingenuity Pathway ...