UNASSIGNED: The duration and the optimal time to adjuvant chemotherapy (TAC) in locally advanced gastric cancer (LAGC) have net not been sufficiently demonstrated. Sequential adjuvant chemotherapy (AC) after neoadjuvant chemotherapy plus gastrectomy is increasingly utilized, making the question more complicated.
UNASSIGNED: Data were collected from patients with LAGC who underwent 5-Fu-based doublet regimens as adjuvant treatment after gastrectomy in a single-center database. TAC and duration (cycles) were used to evaluate survival outcomes.
UNASSIGNED: A total of 816 patients were included. Patients received over six cycles and TAC less than 42 days significantly correlated with better survival (log-rank P trend<0.001). The analysis of TAC and number cycles were separately applied in perioperative chemotherapy (PEC) and postoperative chemotherapy (POC) group using Cox regression. The number of cycles revealed a statistical significance improving OS rate both in POC (HR=0.904, 95% CI=0.836-0.977, P=0.011) and PEC (HR=0.887, 95% CI=0.798-0.986, P=0.026), while only in POC did the TAC show an increasing trend of risk with borderline significance (OS: HR=1.008, 95% CI=0.999-1.018, P=0.094; PFS: HR=1.009, 95% CI=1.000-1.018, P=0.055). A spline model demonstrates the less improvement in survival after cycles of chemotherapy reaching six.
UNASSIGNED: Our findings suggest that TAC is more likely to downregulate the survival benefit in POC rather than PEC, while overall survival is susceptible to cumulative cycles of chemotherapy in both groups. Furthermore, six cycles of chemotherapy tended to reach the maximum survival benefits. Prospective confirmation is required.

Adjuvant chemotherapy following the curative resection could improve the survival outcome of advanced gastric cancer (GC) patients. However, it is unclear whether delayed initiation of adjuvant chemotherapy had a negative impact on survival outcome in GC patients. The purpose of this study was to review current published literature about the impact of delaying adjuvant chemotherapy on survival outcome and summarize risk factors for delaying adjuvant chemotherapy. Delayed initiation of adjuvant chemotherapy was quite frequent in GC patients who underwent gastrectomy due to postoperative complications, poor nutritional status, comorbid diseases and socioeconomic status. Therefore, it is important for these patients to have a sufficient and smooth transition from surgery to initiation of adjuvant chemotherapy. Based on current available evidence, there is no specific timing interval for the initiation of adjuvant chemotherapy in GC patients. Earlier initiation of adjuvant chemotherapy (<4 weeks) may not be mandatory for GC patients who underwent curative resection. However, the patients should be recommended to receive adjuvant chemotherapy within 6-8 weeks if their performance status and nutritional status were deemed to be appropriate. Minimizing postoperative complications and providing requisite nutritional advice may be helpful for timely initiation of adjuvant chemotherapy.

Adjuvant chemotherapy(AC) following the curative resection could improve the survival outcome of advanced gastric cancer(GC) patients. However, there is no specific timing interval from radical surgery to initiation of AC. Whether delayed initiation of AC could affect the survival outcome of these patients remains unclear. In this study, we performed a systematic review and meta-analysis to evaluate the relationship between delaying AC and the survival outcome of GC patients.
PubMed, Embase and Cochrane Library databases were systematically searched for eligible studies that evaluated the relationship between time to AC and survival outcome. Survival data for HR and 95% CI were extracted and converted to a regression coefficient(β) corresponding to a continuous representation per 4-week delay of AC. Individual adjusted β were combined using a fixed-effects or random-effects model. Heterogeneity was assessed by I2 statistic and publication bias was detected using standard error-based funnel plots.
A total of 11 eligible studies involving 6,017 patients were included in this meta-analysis. Eight studies evaluated the impact of delaying AC on overall survival(OS) and five evaluated the impact of delaying AC on disease-free survival(DFS). The pooled results demonstrated that the initiation of AC per 4-week delay was associated with a significant decrease in OS(HR:1.05, 95% CI: 1.03-1.08, P < 0.001; I2 = 18.5%) and DFS (HR:1.06, 95% CI: 1.02-1.10, P = 0.001; I2 = 40.6%).
The initiation of AC per 4-week delay was associated with worse survival outcomes in GC patients. If physical status and postoperative recovery were appropriated, GC patients should be recommended to receive adjuvant chemotherapy timely.