%0 Journal Article
%T Time to initiation or duration of S-1 adjuvant chemotherapy; which really impacts on survival in stage II and III gastric cancer?
%A Fujitani K
%A Kurokawa Y
%A Takeno A
%A Endoh S
%A Ohmori T
%A Fujita J
%A Yamasaki M
%A Takiguchi S
%A Mori M
%A Doki Y
%A  
%J Gastric Cancer
%V 21
%N 3
%D May 2018
%M 28965205
%F 7.701
%R 10.1007/s10120-017-0767-9
%X <B>BACKGROUND: </B>Surgical resection with S-1 adjuvant chemotherapy (AC) is the standard of care for stage II-III gastric cancer (GC). However, it is unclear if time to initiation and duration of S-1 AC impact on survival.<BR><B>METHODS: </B>A multi-institutional GC database identified 498 patients who were treated with S-1 AC after D2 or more extended radical surgery for stage II-III gastric cancer. Patients were divided into four groups according to the interval between surgery and initiation of AC and the duration of AC as follows: group A (n = 226), who received AC earlier (≤6 weeks) and for longer (≥6 months) after surgery; group B (n = 160), who received AC later (>6 weeks) and for longer after surgery; group C (n = 46), who received AC earlier but for a shorter period (<6 months) after surgery; and group D (n = 66), who received AC later and for a shorter period after surgery. Prognostic factors for overall survival (OS) were investigated using multivariate analysis.<BR><B>RESULTS: </B>The 5-year OS was 69.5%. Pathological stage II disease (hazard ratio (HR), 0.334; 95% confidence interval (CI), 0.215-0.499), with an OS of 85.8% versus 60.5% for stage III disease, as well as a longer duration (≥6 months) of S-1 (HR, 0.498; 95% CI, 0.355-0.706), with an OS of 74.3% versus 53.0% for a shorter duration (<6 months) of S-1, were identified as significant prognostic factors for long-term survival. Time to initiation was not associated with OS.<BR><B>CONCLUSIONS: </B>A duration of S-1 AC of ≥6 months, but not time to initiation within 6 weeks, impacts on OS in stage II-III gastric cancer.