The long-term prognostic difference between gastrectomy with and without preoperative chemotherapy in patients with clinical stage IV gastric cancer

Summary: Background/objective: The role of gastrectomy for stage IV gastric cancer (GC) has not yet been established. Thus, we aimed to compare the prognoses of patients with clinical stage IV GC who underwent gastrectomy with and without preoperative chemotherapy after precise recategorization of patients. Methods: We retrospectively reviewed a total of 92 clinical stage IV GC patients who underwent gastrectomy with or without preoperative chemotherapy between 2010 and 2016 at a single institution. Yoshida's classification was used to categorize the patients into the following categories: 1, technically resectable metastasis; 2, marginally resectable metastasis; 3, unresectable peritoneal dissemination; and 4, incurable peritoneal dissemination with distant organ metastasis. Two-year disease-specific survival (DSS) rates were compared between patients who underwent primary surgery and preoperative chemotherapy for each category. Results: The two-year DSS rates of primary surgery vs. preoperative chemotherapy in Categories 1, 2, 3, and 4 (n = 35, 39, 14, and 4, respectively) were 48.6% vs. 41.7% (p = 0.829), 52.6% vs. 40.0% (p = 0.855), 50.0% vs. 75.0% (p = 0.027), and 0% vs. 66.7% (p = 0.083), respectively. Patients in Categories 1 and 2 who underwent preoperative chemotherapy tended to have lower two-year DSS rates (p = 0.911), whereas patients in Categories 3 and 4 had significantly higher two-year DSS rates than those who underwent primary surgery (p = 0.014). Conclusions: Primary surgery may be performed in patients without peritoneal dissemination when GC is technically resectable. However, if peritoneal dissemination is suspected, chemotherapy should be prioritized. Keywords: Carcinomatosis, Chemotherapy, Gastrectomy, Gastric adenocarcinoma