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.