Factors associated with complication after gastrectomy for gastric or esophagogastric cancer compared among surgical purpose, surgical extent, and patient age: Retrospective study from a high volume center in Thailand

•Purpose and extent of surgery were not associated with incidence and severity of postoperative morbidity.•Age ≥70 years in the curative group, and ≥80 years in the palliative group were associated with increasing complications.•Age ≥70 years, CAD, tumor size >5 cm, and operative time >210 min were independent risk factors for complication.•Physician awareness of these risk factors may reduce postoperative complication.