Prognostic effect of surgery of metastases in patients with advanced gastric cancer: Real-world data from the AGAMENON registry

Abstract

Background: The aim of this analysis was to evaluate the prognostic effect of surgery of metastases in patients from a national registry of advanced gastric cancer. Methods: The effect of surgery of metastases was assessed by multivariable Cox proportional hazards regression adjusted by confounding factors. To avoid immortal time bias in variables that occur after the initial period of observation, surgery of metastases, primary tumor resection, and the assessment of tumor response by RECIST were considered as time-dependent variables. All P values are two-sided. Statistical analyses were performed using RStudio, including the survival package. Results: The registry contains 1531 evaluable patients. Of these, 5.3% (n=82) patients underwent surgery for metastases (liver metasectomies were performed in 23 patients, peritoneal surgeries in 39, a pulmonary metastasis excision in 1 patient, and 19 surgeries in other locations). The majority of the cases (53.6%) had a single metastatic location. The median overall survival in non-operated patients was 10.4 months (confidence interval [CI] 95%, 9.9-10.9) versus 19.8 months (CI 95%, 17.4-28.8) in patients with resection of metastases. In the multivariable Cox proportional hazards regression, the resection of metastases was associated with a reduction in mortality with a hazard ratio (HR) of 0.57 (95% CI, 0.43-0.76) (see Table 1). Table 1. Cox proportional hazards regression Conclusions: In this registry of patients with advanced gastric tumors, surgery of metastases appears to confer a favorable survival benefit when performed on carefully selected patients. (Table Presented).