The optimal strategy of multimodality therapies for resectable gastric cancer: evidence from a network meta-analysis

Background: Controversy continues regarding the optimal strategy of multimodality therapies for resectable gastric cancer. The aim of this network meta-analysis was to determine the efficacy of surgery combined with neoadjuvant or adjuvant chemotherapy (CT), radiotherapy (RT), and chemoradiotherapy (CRT) by integrating the direct and indirect method. Methods: A systematic search for randomized controlled trials (RCTs) was performed through Medline, Embase, CENTRAL, and PMC databases. Overall survival (OS) was the primary outcome of interest. A Bayesian network meta-analysis was conducted and treatments were ranked based on their effectiveness for improving survival. Results: Fifty-six RCTs involving 12,435 patients were included. Overall analysis showed that neoadjuvant CRT resulted in a statistically significantly better OS compared with adjuvant CT, adjuvant RT, adjuvant CRT, neoadjuvant CT, neoadjuvant RT, and surgery alone. Moreover, subgroup analysis of D2 lymphadenectomy revealed that neoadjuvant CRT was not significant superior to neoadjuvant CT (HR = 0.67, 95% CrI 0.41-1.08), adjuvant CRT (HR = 0.67, 95% CrI 0.37-1.21), and adjuvant CT (HR = 0.60, 95% CrI 0.35-1.04). With a tendency to survival benefit, neoadjuvant CRT had an 89% probability of being the best selection. Conclusions: Our study showed no significant survival advantage for neoadjuvant CRT, though the highest probability of being the best treatment was observed. Further clinical trials are essential to determine the value of neoadjuvant CRT, especially in D2 lymphadenectomy subgroup.