Prognostic Value Of Gastric Signet Ring Cell Carcinoma

Objective:The prognostic value of signet ring cell carcinoma(SRC)in gastric cancer(GC)is still a point of discussion.This study aims to assess the impact of SRC on long-term survival of GC patients following resection.Methods:All patients with GC treated with surgical resection from 2010 to 2015 were identified in the Surveillance,Epidemiology,and End Results(SEER)database.Based on the topography codes in the 3rd edition of the International Classification of Diseases for Oncology(ICD-O-3),the patients were categorized as SRC(codes8490)and non-SRC(code 8140)groups.Exclusion criteria were patients younger than18 years whose tumor stage,surgery status,primary tumor location,histologic grade and cause of death were all unknown,and the diagnosis of adenocarcinoma or SRC was made by autopsy or death certificates only.Tumor was staged according to the 7th edition of the American Joint Committee on Cancer(AJCC)classification.Propensity score-matching analysis was utilized to assess the overall survival(OS)and disease-specific survival(DSS).Results:Among the 6051 included patients,1246(20.6%)had SRC and 4805(79.4%)had non-SRC.In the analysis of the entire cohort of patients,SRC was found to be significantly associated with younger age,female gender,AJCC stage III,resection of15 or more lymph nodes(LN),poor differentiation(G3 and G4),more extent of LN involvement,advanced tumor stage,larger tumor size,middle location,distant metastasis,radiotherapy,chemotherapy,and total gastrectomy.Both the 5-year OS and DSS rates in SRC group were significantly worse than those in non-SRC group(41.1%vs.44.1%,P = 0.012;43.9% vs.49.8%,P <0.001).After matching,1109 pairs were selected,and it was found that neither OS nor DSS was significantly different between the two groups.At multivariate analysis,SRC did not influence OS(hazard ratio [HR]=1.05,95% confidence interval [CI]: 0.93–1.18,P=0.4661)and DSS(HR =1.01,95%CI: 0.89–1.14,P= 0.907).When patients were stratified by tumor stage,SRC was still found to be not associated with decreased survival outcomes in both early and advanced GC groups.Conclusions:SRC does not negatively impact survival of GC patients,regardless of the disease stage.