Therapeutic value of splenectomy to dissect splenic hilar lymph nodes for type 4 gastric cancer involving the greater curvature, compared with other types.

Background: Whether splenectomy for splenic hilar lymph node (No. 10) dissection in type 4 gastric cancer involving the greater curvature is necessary is not established. Patients with type 4 gastric cancer often experience peritoneal relapse, despite curative surgery, and total gastrectomy with splenectomy is frequently associated with infectious complications.

Method: Patients with cT2-T4 gastric cancer in the upper or middle third of the stomach, or both, involving the greater curvature who underwent R0 total gastrectomy with splenectomy between 2006 and 2016 were selected. Clinicopathological findings, postoperative complications, the incidence of lymph node metastasis, and the therapeutic value index of each station were compared between type 4 and non-type 4 gastric cancer.

Results: We enrolled 50 patients with type 4 and 60 with non-type 4. The former had a significantly higher proportion of the undifferentiated type and larger and deeper tumors. The overall incidence of Grade III or higher complications was 20.9%. The incidence of No. 10 metastasis was 26.0% in type 4 and 31.7% in non-type 4. Although the therapeutic value index of the No. 10 was 13.7 in type 4 and 15.0 in non-type 4, the index of type 4 ranked just below several peri-gastric stations and seventh, while that in non-type 4 ranked second.

Conclusion: Splenectomy for No. 10 dissection may be oncologically valid for type 4 gastric cancer involving the greater curvature. A safer procedure for No. 10 dissection should be established.