Proteomic features of colorectal cancer independently predict relapse-free survival.

616 Background: Proteomic analysis continues to provide major insight into the pathophysiology of colorectal cancer (CRC). Recently, the Cancer Genome Atlas Project and others have utilized reverse-phase protein arrays (RPPAs) to identify critical protein markers and signaling pathways in a variety of tumor types. However, the prognostic relevance of many of these proteins remains unclear. We utilized RPPA to analyze stage 2 and 3 CRC to investigate the prognostic implications of the functional proteome. Methods: Protein extraction was performed on 232 snap frozen stage 2/3 samples from the MD Anderson Cancer Center with a median 5 year follow up. 163 validated proteins and phospho-proteins were analyzed by RPPA (with dichotomization by the median value), and used to identify protein predictors of tumor recurrence. Cox regression was used for univariate analysis with bootstrap validation, followed by inclusion of proteins with corrected p≤ 0.05 into multivariate model with clinical and pathologic variable...