Can distal gastrectomy be considered a treatment option for localized type 4 gastric cancer?

408 Background: Borrmann Type 4 gastric cancer is defined as diffuse infiltrative type cancer without ulceration. This type of cancer typically involves the entire stomach, and total gastrectomy (TG) is generally indicated. However, in patients with localized tumor without involvement of upper third of the stomach, distal gastrectomy (DG) is sometimes performed in clinical practice and may achieve R0 resection. In order to evaluate the feasibility of DG as a treatment option for localized type 4 gastric cancer without involvement of upper third of the stomach, short-term and long-term outcomes of DG was compared with TG. Methods: We retrospectively identified 65 patients clinically diagnosed with type 4 gastric cancer who underwent R0 resection at Shizuoka Cancer Center between 2008 and 2022. Among them, patients with clinical invasion of the upper portion (n=45), and those who received preoperative chemotherapy (n=2) were excluded. Finally, 18 patients were included in the analysis. Clinicopathological characteristics and survival outcomes were compared between the groups. Results: DG was performed in 8 patients and TG in 10 patients. Clinical characteristics were comparable between the two groups. Regarding surgical findings, all patients underwent D2+ lymphadenectomy with splenectomy in TG group, while D2 or D2+ was performed in 88 % of the patients in DG group. The incidence of postoperative complication (Clavien-Dindo Grade II or higher) was 50 % in DG group and 40 % in TG group (p = 1.000). There was one mortality in DG group. In DG group, there were 1 patient with pT1 and 2 patients with pT2. On the contrary, all patients were pT3 or pT4 in TG group. There were 3 patients with pStage I in DG group, while all patients were pStage II or pStage III in TG group. Accordingly, adjuvant chemotherapy was performed in all patients in TG group, however, in 50 % of the patients in DG group. Recurrence occurred in 2 patients (25%; lymph nodes, n=1; liver, n=1) of DG group and 7 patients (70%; peritoneum, n=6; liver, n=1) of TG group. Survival analysis was performed excluding pStage I patients. Overall survival tended to be better in DG group, however, there was no statistically significant difference (HR: 2.15, 95% CI 0.44-10.46, p = 0.332). Similarly, there was no significant difference of relapse-free survival (HR: 2.44, 95% CI 0.49-12.17, p = 0.263) and disease-specific survival (HR: 4.44, 95% CI 0.54-36.47, p = 0.13). Conclusions: DG appears to be a feasible treatment option for localized type 4 gastric cancer with comparable short-term and long-term outcomes with TG. However, intraoperative confirmation of a negative proximal margin by frozen section may be essential.