Survival impact of adjuvant regimens for advanced gastric cancer after radical D2 resection in a Peruvian population.

Abstract

e15576 Background: The benefit of chemoradiotherapy(CRT) or chemotherapy (CT) for gastric cancer with high metastatic lymph node involvement after complete radical D2 resection is still controversial, previous studies had reported better disease free survival (DFS) but no differences in overall survival (OS). Our aim was to compare DFS and OS between CRT and CT. Methods: Retrospectively, 201 medical records were reviewed from patients with advanced gastric cancer (nodes +ve) after complete radical D2 resection between 2008 and 2012 at Instituto Nacional de Enfermedades Neoplasicas (Peru). Patients received CRT (5FU and RT as Macdonald’s protocol) or CT (capecitabine 2g/m2/14days + oxaliplatin 135mg/m2/day1 q21d for 6months). We describe clinical and pathological characteristics, DFS/OS with univariate and multivariate cox analysis were performed. Results: Mean age was 54.4years [19-83] and 17.9% were < 40years. Distal localization (46%), high histological grade (69.7%) and poorly cohesive subtype (38.3%) were most frequent characteristics among patients, 140(69.7%) and 130(64.7%) were T4 and N3, respectively. From 201 patients, 134 underwent to CRT and 67 to CT, with no clinical differences between groups. We observed a significant higher nodal ratio in CT group (0.27 vs 0.35, p = 0.009). 69.5% patients completed treatment with CRT, while only 54.5% in CT (p = 0.04). At 5years median of follow-up, 66 (49.3%) and 26(38.8%) recurrences were documented in CRT and CT groups, respectively. Median DFS were 19 and 23 months in CRT and CT group (HR:1.04, 95%CI:0.7-1.4, p = 0.8), while median OS were 25 and 26 months, respectively (HR:1.07, 95%CI:0.75-1-5, p = 0.6). At multivariate analysis, higher T stage and nodal ratio were associated to worse DFS, and patients who completed treatment were associated to better DFS (HR:0.59, 95%CI:0.4-0.8, p = 0.004). Higher T stage and nodal ratio had significant negative impact on OS. Conclusions: We found a benefit of CT over CRT in gastric cancer with high metastatic lymph nodes, however in our population it was not statistically significant, indeed further larger clinical trials are needed. In this study, higher T stage and nodal ratio were associated to worse prognosis.