Preoperative therapy and long-term survival in gastric cancer: One size does not fit all

Background: The administration of perioperative chemotherapy represents the Western standard of care for patients with locally advanced gastric cancer. The aim of this study is to determine if the administration of the preoperative component of the perioperative regimen is beneficial in the entire population of patients with locally advanced gastric cancer. Methods: Seventy patients undergoing preoperative therapy were compared with 347 patients undergoing upfront gastrectomy. Survival analyses were conducted with Kaplan-Meier curves and Cox regression. Patients undergoing preoperative therapy or undergoing upfront gastrectomy were matched 1:1 using the propensity score matching (PSM) method, and a survival analysis was conducted on matched patients. A subgroup analysis was conducted by tumor location and Lauren histotype. Results: In patients undergoing preoperative therapy, factors significantly associated with survival were T and N downstaging, type of gastrectomy, resection status and Lauren histotype. Preoperative therapy was not significantly associated with survival (p = 0,761 before PSM and p = 0,519 after PSM). After PSM, the independent variables significantly associated with survival were type of gastrectomy, type of lymphadenectomy, R status and postoperative therapy. In the subgroup analysis, preoperative therapy demonstrated a selective association with the location of the tumor (p = 0,055) and with Lauren intestinal histotype (p = 0,002). Conclusions: Preoperative therapy had a non-significant impact on survival in the entire population of gastric cancer patients. The advantage of preoperative therapy seems to be limited to patients with proximal tumors and an intestinal histology. Future studies should better evaluate the diverse response of the different phenotypes of gastric cancer to preoperative therapy