658P - A Retrospective Analysis of the Relation Between Durations of Adjuvant Chemotherapy with Its Effects on Overall Survival and Relapse Free Survival in Stage Ii or III Gastric Cancer

Abstract

ABSTRACT Aim: This study was conducted to propose the optimal duration of adjuvant chemotherapy in stage II or III gastric cancer regardless of treatment regimens, which had been introduced from the oral fluoropyrimidine derivatives to the intravenous fluoropyrimidine combined with platinums. Methods: We retrospectively analyzed data from 2198 patients with histologically confirmed gastric cancer who underwent curative gastrectomy with D2 lymphadenectomy between 2005 and 2012. 1347 patients (61.3 %) were treated by surgery alone due to early stage or patients' refusal of chemotherapy and 851 patients (38.7%) of stage II or III gastric cancer were treated with diverse durations and various kinds of adjuvant chemotherapy. The duration of adjuvant chemotherapy less than 6 months [Group 1] was 343 patients (40.3%), from 6 months to less than 12 months [Group 2] was 179 patients (21.0%), from 1 year to less than 2 years was [Group 3] 240 patients (28.2%) and over 2 years [Group 4] was 89 patients (10.5%). Results: Overall survival (OS) and relapse free survival (RFS) were analyzed according to durations of adjuvant chemotherapy. Median follow-up duration was 3.82 years. Each median OS in Group 1, 2, 3, and 4 was 3.07 years (reference), 3.24 years (hazard ratio [HR] 1.019, 95% CI, 0.520 to 1.997, p-value 0.956), 4.06 years (HR 0.485 95% CI, 0.243 to 0.966, p-value 0.040*) and 4.87 years (HR 0.368, 95% CI, 0.128 to 1.058, p-value 0.064). Each median RFS in Group 1,2,3 and 4 was 2.68 years (reference), 3.06 years (HR 0.948, 95% CI, 0.484 to 1.854, p-value 0.875), 4.02 years (HR, 0.494 95% CI, 0.248 to 0.985, p-value 0.045*) and 4.76 years (HR, 0.392 95% CI, 0.136 to 1.127, p-value 0.082). * p Conclusions: We concluded that a prospective cohort study should be performed to figure out the longer period of adjuvant chemotherapy in gastric cancers could obtain much higher OS and RFS. Disclosure: All authors have declared no conflicts of interest.