BACKGROUND: Patients aged >
80-years-old with gastric cancer are commonly excluded from clinical trials, and no consensus exists regarding surgical indications and outcomes in older patients. In this study, we analyzed the post-gastrectomy long-term survival and etiologies of mortality in older patients with gastric cancer. METHODS: Patients aged >
80-years-old with pathological stages I-III primary gastric cancer who undergone radical gastrectomies, between May 2006 and March 2017, were included in the study. Eligible patients were categorized into 3 age cohorts: <
85-, 85-90-, and >
90-years-old. The primary outcome was the overall survival. The etiologies of mortalities were compared. Survival curves were compared using the log-rank test. Prognostic factors were identified by multivariate analysis, using the Cox proportional hazards regression model. RESULTS: The median follow-up duration was 59 months. Of the 353 patients, 269 (76.2%), 71 (20.1%), and 13 (3.7%) were categorized into the <
85-, 85-90-, >
90-years-old age cohorts, respectively. Older patients had a poorer overall survival (p = 0.003) and statistically significant difference in the other-cause survival (p <
0.002). The multivariate analysis revealed that age was not an independent prognostic factor for overall or cancer-specific survival. However, an age >
90-years-old was an independent prognostic factor for the other-cause survival. CONCLUSIONS: In patients aged >
80-years-old with gastric cancer who had undergone gastrectomies, mortalities from other diseases increased with age
while mortalities from gastric cancer did not. An age of ≥90-years-old was an independent prognostic factor for mortalities from other diseases.