Rectal adenocarcinoma: Outcomes of adjuvant chemotherapy after neoajuvant chemoradiotherapy in a retrospective cohort.

790Background: The role of adjuvant chemotherapy (AC) after chemoradiotherapy and surgery in stage II and III of rectal cancer is not well defined. Neither the regimen nor the duration is clear. Besides, guidelines from different expert groups are conflicting. Methods: 224 patients diagnosed from January 2003 to December 2013 with rectal adenocarcinoma T3/T4 and/or positive node staged by ultrasound or magnetic resonance imaging was collected retrospectively from the Pathology Department data base. Results: Of the 224 patients 61.6% were male, median of age at diagnosis 68.6 years (range 31.3-85.4). All of them received 50.4 Gy with different concomitant regimens (capecitabine, continuous infusion of fluoracil or bolus of fluoracil-leucovorin). 13.4% of patients achieved a pathological complete response. 76.8% of the cohort received adjuvant chemotherapy. The main reasons for not receiving chemotherapy were ECOG ≥ 2, surgery complications and a decision of the patient. 51.2% of patients received an oxalip...