Background: Adjuvant chemotherapy improves survival in patients with gastric cancer. However, the relationship between the timing of adjuvant chemotherapy and survival has not been investigated.
Methods: 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.
Results: 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).
Conclusions: 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.