Background: No national studies comparing long-term survival after total or partial gastrectomy with splenectomy due to injury or oncologic reasons or spleen preservation exist. This study aimed to examine the 5-year overall survival (OS) of patients with gastric adenocarcinoma who underwent total or partial gastrectomy with splenectomy due to injury or oncologic reasons or spleen preservation in a population-based nationwide setting.

Methods: This study included all patients undergoing total or partial gastrectomy with splenectomy or spleen preservation for gastric adenocarcinoma in Finland from 2005 to 2016, with follow-up until December 31, 2019. A total of 2196 patients with gastric cancer diagnosis and total or partial gastrectomy were identified in the registries. Of these patients, 2118 were applicable for this study. Cox proportional hazard models provided hazard ratios (HRs) with 95% CIs of 5-year OS. The results were adjusted for age, sex, year of operation, comorbidities, tumor location, pathologic stage, and neoadjuvant therapy.

Results: The observed 5-year OS rates were 38.7% in patients with no or minor spleen injury, 39.7% in patients with splenectomy due to injury, and 30.8% in patients with splenectomy due to oncologic reasons (P = .032). Patients who underwent R0 gastrectomy with splenectomy due to oncologic reasons had higher 5-year mortality (the adjusted model HR, 1.26; 95% CI, 1.01-1.56) than patients who underwent spleen preservation.

Conclusion: The OS was worst in patients who underwent gastrectomy with splenectomy due to oncologic reasons, highlighting the poor prognosis in patients with advanced gastric cancer. Splenectomy due to injury does not compromise the prognosis.