Effectiveness of conversion surgery in stage IV gastric cancer

Background: For patients with stage IV gastric cancer (GC), systemic therapy is often the standard treatment, but the prognosis remains poor. Conversion surgery (CS) has emerged as a potential therapeutic option for selected patients who had certain response to chemotherapy. This study aims to compare the survival outcomes of CS versus continued chemotherapy (CT) in stage IV GC. Methods: We conducted a retrospective cohort study of 52 patients with stage IV gastric adenocarcinoma, from January-2018 to June-2023. Patients were divided into two groups: those who underwent CS (CS group) after a response to chemotherapy and those who continued with systemic chemotherapy (CT group). Baseline characteristics, chemotherapy toxicity, surgical outcomes, and survival data were analyzed and compared. Results: Among 52 patients, 26 patients underwent CS, while other 26 continued with CT. The CS group showed a significantly higher 3-year overall survival (OS) rate and median survival time (MST) compared to the CT group (36 % vs. 15 %, HR = 0.39, 95%CI: 0.19-0.79, p = 0.009; 23.4 months vs. 14.7 months, p < 0.001, respectively). Subgroup analysis by Yoshida classification revealed superior survival outcomes for CS in category 3 (MST: 26.1 months vs. 12.6 months, p < 0.001). Multivariate analysis indicated that CS were associated with a longer survival. No major postoperative complications were observed in the CS group. Conclusions: Conversion surgery improved survival outcomes in selected stage IV GC patients compared to systemic chemotherapy alone. CS should be considered as a treatment option for patients who responds to initial chemotherapy, particularly those in Yoshida category 3.