Boston - American Association for Thoracic Surgery

89 TH ANNUAL MEETING MAY 9–MAY 13, 2009BOSTON, MASSACHUSETTSF11. MicroRNA Expression Profiles Predict Recurrence After Surgeryfor Stage 1 Non-Small Cell Lung CancerSai Yendamuri, 1 Steen Knudsen, 2 Todd L. Demmy, 1* Santosh Patnaik 11. Roswell Park Cancer Institute, Buffalo, NY, USA; 2. Medical PrognosisInstitute, Horsholm, DenmarkInvited Discussant: Virginia R. LitleOBJECTIVE: Surgery for stage 1 NSCLC has a significant recurrence rate. A toolfor predicting recurrence in these patients may direct adjuvant therapy to high riskpatients to maximize its risk benefit ratio. We studied the ability of an updatedmicroRNA (miRNA) microarray to predict recurrence in patients with pathologicstage 1 NSCLC.METHODS: Formalin fixed paraffin embedded (FFPE) tissue specimens from 79patients with pathologic stage 1 NSCLC were used for analysis. Tissue was deparaffinizedand miRNA extracted. After quality control assessments of the extractedRNA, hybridization was performed to a locked nucleic acid based array platformcontaining probes for all miRs in miRBase version 11. Data from the arrays werebackground corrected and Loess normalized. In a leave-one-out cross validation,miRNAs differentially expressed between patients with recurrence and patientswithout, were selected with a t-test, using a multiple testing correction leaving afalse discovery rate of 1%. The resulting miRNAs were subjected to Principal ComponentAnalysis. The five most important components trained a multivariate classifierusing the classification algorithms: K nearest neighbor, nearest centroid, neuralnetwork and support vector machine. The left out sample was predicted by majorityvote among the classification algorithms into “Good Prognosis” or “Poor Prognosis”.A Kaplan-Meier plot was prepared of the time to recurrence for the “Good Prognosis”and “Poor Prognosis” groups. A log-rank test for statistical significance of thedifference between the two groups was performed. As a leave one out cross validationwas performed, separate internal training and test sets were not created.* AATS Member138