LAUSR

621Title: Effects of Proton Pump Inhibitors (PPIs) on FOLFOX and XELOX Regimens in Colorectal Cancer (CRC) Background: First-line adjuvant chemotherapy options for stage II-III CRC include XELOX (capecitabine (cape), oxaliplatin) and FOLFOX (oxaliplatin, leucovorin, 5FU). Cape is an oral 5FU prodrug, and recent studies suggested that PPIs may detrimentally affect cape efficacy. Conversely, some literature posits that PPIs may negatively impact CRC itself. Our primary objective was to compare 3-year recurrence-free survival (RFS) rates between XELOX-treated PPI-users and non-PPI users, and FOLFOX-treated PPI users and non-PPI users. Our main secondary objective was to compare overall survival (OS). Methods: We conducted a retrospective chart review of 389 stage II-III CRC patients (pts) who received adjuvant XELOX or FOLFOX from a tertiary cancer center in Alberta, Canada between 2004-2013. Information regarding PPI use, cancer treatment, and pt outcomes were gathered and analyzed from pharmacy databases. ...