Supplementary Material for: Identifying risk factors of complications following total gastrectomy for gastric cancer – comparison between splenectomy and spleen-preserving surgery: a supplementary analysis of JCOG0110

Introduction: Splenectomy for proximal gastric cancer was found to offer no survival benefit in a randomized trial clarifying the role of splenectomy (JCOG0110 study). Although many studies have explored risk factors for morbidities following total gastrectomy, none have assessed the risk factors for postoperative complications in spleen preserving total gastrectomy. Methods: Using data from 505 patients enrolled in a previous randomized trial, risk factors for postoperative complications were identified by multivariable logistic regression analysis. Then, the risk factors were assessed separately between splenectomy and spleen preserving total gastrectomy. Results: Postoperative complications were identified in 119 patients (23.6%) and were more common following splenectomy than following spleen-preserving surgery (30.7% and 16.1% respectively, P<0.01). Multivariable analysis revealed that age ≥65 years (P = 0.032), body mass index ≥25 (P = 0.003), and blood loss ≥350 g (P = 0.019) were independent risk factors for postoperative complications in the entire cohort. Among them, only body mass index was a significant independent risk factor for complications in both spleen preservation (P = 0.047) and splenectomy groups (P = 0.017). Conclusion: Risk factors for postoperative complications were essentially the same between splenectomy and spleen preservation. Being overweight increased the risk of postoperative complications in spleen-preserving total gastrectomy.