Clinicopathological Features And Impact Of Adjuvant Chemotherapy On The Long-term Survival Of Patients With Multiple Gastric Cancers

Background Whether multiple gastric cancers(MGC)have different clinicopathological characteristics from solitary gastric cancers(SGC)is still controversial.No previous studies have investigated the relationship between postoperative treatment and prognosis of MGC.Objective To investigate the clinicopathological features and prognosis of patients with MGC and to explore the impact of postoperative adjuvant chemotherapy on long-term survival.Methods The clinical and pathological data of patients diagnosed with gastric adenocarcinoma who had radical gastrectomy from January 2007 to December 2016 were analyzed.The 1: 4 propensity score matching was used to balance the differences between MGC and SGC groups.The Kaplan Meier method was used to compare the survival difference and the effect of postoperative adjuvant chemotherapy on prognosis.The Cox proportional hazards model was used for identifying the prognostic risk factors.Results Among the 4107 patients investigated,the incidence of MGC was 3.2%(133/4107).Before matching,patients with MGC and SGC had disparities in the type of gastrectomy,pathological tumor(p T)stage,pathological node(p N)stage,and pathological tumor node metastasis(p TNM)stage(all P < 0.05).After a 1:4 ratio matching,the clinicopathological data of 133 cases of MGC and 532 cases of SGC were found to be comparable(all P > 0.05).After matching,the 5 year overall survival(OS)rate was 56.6% in the entire matched cohort,48.1% in the MGC group,and 58.7% in the SGC group(P = 0.013).When stratified based on p T stage,the 5-year OS rates between early MGC and SGC were found to be no statistically significant difference(83.3% vs.91.8%,P = 0.852).But the 5-year OS rates of the advanced MGC and SGC were 43.0% and 51.1% respectively,with significant differences(P = 0.036).Multivariate analysis revealed that MGC,age,p T stage,p N stage,and adjuvant chemotherapy were independent predictors of OS(all P < 0.05).Stratified analyses demonstrated that for the cohort of advanced gastric cancer who did not had adjuvant chemotherapy,the 5 year OS rate of advanced MGC was inferior than that of SGC(34.0% vs.46.1%,P = 0.025).But there were no significant differences in the 5 year OS rates between advanced MGC and SGC patients who had adjuvant chemotherapy(48.0% vs.53.3%,P = 0.292).Further,we found that the 5 year OS rate of advanced MGC who had adjuvant chemotherapy was significantly higher than those who did not had adjuvant chemotherapy(48.0% vs.34.0%,P = 0.026).Conclusion Compared with SGC,MGC had deeper depths of invasion,greater number of lymph node metastases,and more advanced pathological stages.Patients with advanced MGC was identified as having a poorer survival as to SGC patients,but the implementation of postoperative adjuvant chemotherapy showed that it had the potential to significantly improve the long term prognoses of MGC patients.