Proper Timing of Adjuvant Chemotherapy Affects Survival in Patients with Stage 2 and 3 Gastric Cancer

Adjuvant chemotherapy improves survival in patients with gastric cancer. However, the relationship between the timing of adjuvant chemotherapy and survival has not been investigated. Patients with D2-resected stage 2 and 3 gastric cancer that received adjuvant chemotherapy from 2005 to 2011 at Yonsei University Health System were included. The patients were grouped according to intervals between surgery and adjuvant chemotherapy. Among 840 patients, the interval from surgery to the start of adjuvant therapy was less than 4 weeks in 337 (40.1 %) patients (early group), 4-8 weeks in 467 (55.6 %) patients (intermediate group), and more than 8 weeks in 36 (4.3 %) patients (late group). The 5-year RFS was 55.7 % in the early group, 54.4 % in the intermediate group, and 43.6 % in the late group (p = 0.076). The corresponding 5-year OS rates were 63.4, 62.8, and 51.7 % (p = 0.037). There is insufficient evidence to suggest starting adjuvant chemotherapy within 4 weeks after surgery for patients with D2 resected stage 2 and 3 gastric cancer. However, delayed treatment of adjuvant chemotherapy after 8 weeks showed worse survival outcomes than early and intermediate treatment initiation, suggesting that adjuvant chemotherapy should be considered start within 8 weeks after radical resection.