Purpose: The clinical benefit of conversion surgery (CS) for unresectable gastric cancer (GC), whereby unresectable GC responds to chemotherapy and subsequently receives curative-intent surgery, remains unclear. Here, we aimed to clarify the clinical value of CS.
Methods: In this retrospective cohort study, we analyzed 175 unresectable GC, who received triple combined chemotherapy between 2004 and 2019. We divided patients into two groups: those who underwent CS and those receiving chemotherapy only (CS and C groups, respectively). Propensity score matching was used to minimize confounding bias.
Results: Of 175 cases, 61 (34.9%) underwent CS. R0 resection was obtained in 85.2%. After matching, 44 pairs were selected; there were no significant differences in baseline covariants. Group CS had a significantly better median overall survival (OS) (18.8 vs. 46.0 months, p < 0.001), and prolonged progression-free survival (7.4 vs. 25.8 months, p < 0.001). Subgroup analysis of OS showed a favorable trend for CS for almost all subgroups. Multivariate analysis revealed that good ECOG performance status and CS were associated with a longer OS.
Conclusion: The survival benefit of CS was consistently demonstrated in the univariate and multivariate analysis, even in the matched cohort. Additional large-scale trials are needed for further validation.
Keywords: Chemotherapy; Conversion surgery; Conversion therapy; Gastric cancer; Propensity score.