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.