P-239 - Impact of adding oxaliplatin to fluoropyrimidines in the adjuvant therapy in stage II in colon cancer: Experience in Ramon y Cajal Universitary Hospital

Abstract

Introduction: The addition of oxaliplatin to fluorouracil and leucovorin as adjuvant chemotherapy (AC) for patients with stage II and III colon cancer (CC) has been analyzed in two large, randomized trials, MOSAIC and C-07 trials. The updated results of these studies showed that the addition of oxaliplatin enhances overall survival by approximately 5% in patients with stage III disease but has no effect in patients with stage II disease. Methods: We retrospectively included patients with stage II CC that were operated between 2009 and 2014 in the Ramon y Cajal University Hospital. We perform a multivariable Cox model analysis to estimate the benefit of the chemotherapy stratifying by oxaliplatin. We have analyzed whether receiving AC improves the relapse free survival (RFS) and overall survival (OS) and has been stratified according to the presence of at least one classic high risk factor (HRF). Additionally, it has been evaluated whether the addition of oxaliplatin improves the results. Results: 246 were identified. 151 were men (61%). 117 patients had at least one HRF (47%), 52 received AC (44%) of which 33 with oxaliplatin (63%). Patients without any HRF, 27 received AC (21%) of which 19 with oxaliplatin (70%). The median follow-up was 58.2 months. Globally, adjuvant chemotherapy (either with some HRF or without any) showed no benefit in RFS (Hazard ratio (HR) of 1.48 and 1.36, respectively). The benefit in OS was significant for patients with at least one HRF (HR 0.33, p: 0.007) but not in those patients without any HRF (HR 0.52, p: 0.54). Patients with stage II treated with oxaliplatin and fluoropyrimidines showed no benefit in terms of RFS neither with any HRF (HR 0.58, p: 0.33) nor without any (HR 1.11, p 0.936). In terms of OS, there is only benefit in those patients with some HRF (HR 0.16, p: 0.03). Conclusion: The AC in patients with stage II show benefit in OS in those patients with at least one HRF, especially with the addition of oxaliplatin. In those patients without any HRF, there is no benefit with AC, even with addition of oxaliplatin.