Preoperative Radiotherapy Is Associated With Significant Survival Benefits for Patients With Gastric Signet Ring Cell Carcinoma: A SEER-Based Approach

Objective: To explore the clinical and pathological features of gastric signet ring cell carcinoma, and evaluate the survival impact of preoperative radiotherapy on these patients. Methods: The Surveillance, Epidemiology, and End Results database was used to extract eligible patients from 2004 to 2015. The patients were divided into those with and without preoperative radiotherapy. The categorical variables were described by chi-square tests. The patients' survival was compared between the 2 groups by Kaplan-Meier method with log-rank tests. Cox proportional hazard model was adopted to identify prognostic factors of cancer-specific survival. Results: Totally 4771 patients were recruited, of whom 218(4.6%) patients received preoperative radiotherapy, while 4553(95.4%) patients didn't receive this treatment. Survival analysis of the entire cohort demonstrated that preoperative radiotherapy improved both cancer-specific survival and overall survival (p < 0.001) of the patients. Cox proportional hazard models identified age >60, tumor size >50 mm, TNM stage II-IV as independent risk factors for poor prognosis (HR > 1, p < 0.05). Notably, preoperative radiotherapy was identified as an independent protective factor for favorable prognosis (HR < 1, p < 0.05). Subgroup survival analysis showed that preoperative radiotherapy exerted significant survival benefits for the stages III and IV patients. Conclusions: In this population-based study, preoperative radiotherapy is associated with significant survival benefits for the patients with advanced gastric signet ring cell carcinoma. Hence preoperative radiotherapy is feasible for these patients.