High incidence of other primary malignancies in patients with synchronous multiple gastric cancers "a multi-center retrospective cohort study".

This study evaluated the relationship between synchronous multiple gastric cancer and other primary malignancies. During 2002-2013, 1094 consecutive surgically treated gastric cancer patients were enrolled. Preoperatively, we performed total colonoscopy and whole-body computed tomography. When malignancies in other organs were suspected, detailed organ-specific examinations were performed. Synchronous multiple gastric cancer occurred in 102 patients (9.3%)which was frequently observed in patients with preoperative other primary malignancies ( < 0.001). Preoperative other primary malignancy was an independent risk factor for synchronous multiple gastric cancer ( = 0.001; hazard ratio: 2.145, 95% confidence interval: 1.354-3.399) and an independent prognostic factor of overall survival in patients undergoing gastrectomy with curative intent ( = 0.021; hazard ratio: 1.481, 95% confidence interval: 1.060-2.070). Thus, patients with preoperative other primary malignancies have a high risk of synchronous multiple gastric cancer. Careful preoperative examination is recommended to improve survival.