The association between the duration of fluoropyrimidine-based adjuvant chemotherapy and survival in stage II or III gastric cancer

BACKGROUND This study was conducted to propose the optimal duration of fluoropyrimidine-based adjuvant chemotherapy consisting of fluoropyrimidine derivatives alone or combined with intravenous platinum for stage II or III gastric cancer (GC). METHODS We analyzed retrospectively the data from 2219 patients with histologically confirmed adenocarcinoma in the stomach, who underwent a curative gastrectomy with lymphadenectomy from 2005 to 2012. Five-year overall survival (OS) and 3-year relapse-free survival (RFS) were analyzed according to the duration of fluoropyrimidine-based adjuvant chemotherapy. RESULTS Data from 617 patients with stage II or III GC were analyzable; 187 patients (30.3%) were treated with surgery alone, while 430 patients (69.7%) were treated with postoperative adjuvant chemotherapy. The duration of adjuvant chemotherapy was less than 6 months [group 1] in 147 patients (34.2%), 6 months to less than 12 months [group 2] in 94 patients (21.9%), 1 year to less than 2 years [group 3] in 139 patients (32.3%), and over 2 years [group 4] in 50 patients (11.6%). The 5-year OS in groups 1, 2, 3, and 4 was 75.7, 87, 90.3, and 93.4%, respectively, while 3-year RFS was 52.5, 58.8, 81.4, and 94.0%, respectively. CONCLUSIONS In this retrospective study, we did not demonstrate any significant improvement in OS and RFS by longer periods of fluoropyrimidine-based adjuvant chemotherapy in stage II or III GCs. Further prospective randomized studies are needed.