PREOPERATIVE CHEMOTHERAPY VERSUS UPFRONT SURGERY FOR ADVANCED GASTRIC CANCER: A PROPENSITY SCORE MATCHING ANALYSIS.

BACKGROUND: Surgical resection remains the main curative therapeutic modality for advanced gastric cancer. Recently, the association of preoperative chemotherapy has allowed the improvement of results without increasing surgical complications.

AIMS: To evaluate the surgical and oncological outcomes of preoperative chemotherapy in a real-world setting.

METHODS: A retrospective review of gastric cancer patients who underwent gastrectomy was performed. Patients were divided into two groups for analysis: upfront surgery and preoperative chemotherapy. The propensity score matching analysis, including 9 variables, was applied to adjust for potential confounding factors.

RESULTS: Of the 536 patients included, 112 (20.9%) were referred for preoperative chemotherapy. Before the propensity score matching analysis, the groups were different in terms of age, hemoglobin level, node metastasis at clinical stage- status, and extent of gastrectomy. After the analysis, 112 patients were stratified for each group. Both were similar for all variables assigned in the score. Patients in the preoperative chemotherapy group had less advanced postoperative p staging (p=0.010), postoperative n staging (p<0.001), and pTNM stage (p<0.001). Postoperative complications, 30- and 90-days mortality were similar between both groups. Before the propensity score matching analysis, there was no difference in survival between the groups. After the analysis, patients in the preoperative chemotherapy group had better overall survival compared to upfront surgery group (p=0.012). Multivariate analyses demonstrated that American Society of Anesthesiologists III/IV category and the presence of lymph node metastasis were factors significantly associated with worse overall survival.

CONCLUSIONS: Preoperative chemotherapy was associated with increased survival in gastric cancer. There was no difference in the postoperative complication rate and mortality compared to upfront surgery.