Clinical significance of intraperitoneal paclitaxel combined with systemic chemotherapy for gastric cancer with peritoneal metastasis

Background Despite investigations of intraperitoneal paclitaxel as a personalized treatment for peritoneal metastasis of gastric cancer, few studies have evaluated its prognostic impact on conversion surgery for unresectable gastric cancer with peritoneal metastasis. Our study aimed to close this gap in knowledge. Methods We retrospectively enrolled 128 patients who underwent chemotherapy for peritoneal metastasis from gastric cancer and assigned them into intraperitoneal (IP) ( n = 36) and non-IP ( n = 92) groups, based on the use of intraperitoneal paclitaxel plus systemic chemotherapy. Results Disease control rates were 94% and 69% in the IP and non-IP groups, respectively, with the former having a significantly higher tumor response rate than the latter ( p < 0.01). The median survival times in the IP and non-IP groups were 665 and 359 days, respectively, with the former having significantly better prognosis than the latter ( p = 0.02). Fifteen (42%) and sixteen (17%) patients underwent conversion surgery after chemotherapy in the IP and non-IP groups, respectively, with the former having a significantly higher conversion surgery induction rate than the latter ( p < 0.01). Although the prognosis of the conversion surgery group was significantly better than that of the non-conversion surgery group ( p < 0.01), there was no significant difference in prognosis between patients in the IP and non-IP groups who underwent conversion surgery ( p = 0.22). Multivariate analysis identified performance status and conversion surgery as independent prognostic factors (all p < 0.01). Conclusion Our study demonstrated that the IP chemotherapy was one of important factors for conversion surgery induction, while it was not a risk factor for prognosis.