Clinical efficacy of Xiaotan Sanjie decoction in treating gastric cancer with peritoneal metastases: A study protocol for a randomized controlled trial

Background: Gastric cancer (GC) is a highly prevalent malignancy worldwide. Approximately 20%-43% of patients present with peritoneal metastasis (PM) at initial diagnosis, resulting in a 5-year survival rate of less than 20%. Peritoneal metastasis frequently induces severe complications including malignant ascites and intestinal obstruction, significantly compromising patients' quality of life. Traditional Chinese Medicine (TCM) has demonstrated unique advantages in GC treatment. Xiaotan Sanjie (XTSJ) decoction, an empirical prescription based on the "phlegm syndrome" theory, has been shown in previous studies to inhibit GC proliferation and metastasis, modulate immune function, and enhance therapeutic efficacy while reducing toxicity. However, no scientific evidence currently supports the clinical efficacy of XTSJ decoction specifically in treating GC with peritoneal metastasis (GCPM). Therefore, this study aims to evaluate the efficacy and safety of XTSJ decoction in managing GCPM. Methods/Design: The study protocol has been approved by the ethics committee and registered with the International Traditional Medicine Clinical Trial Registry. This prospective randomized controlled clinical trial will enroll 150 GCPM patients who will be randomly assigned in a 1:1 ratio to either the TCM treatment group or the conventional treatment group. Each group will undergo two treatment cycles totaling 6 weeks. The primary outcome measure is the clinical objective response rate (ORR). Secondary outcome measures include progression-free survival (PFS), overall survival (OS), tumor markers, peripheral blood immune indices, high-sensitivity modified Glasgow Prognostic Score (HS-mGPS), Karnofsky Performance Status (KPS) score, and Eastern Cooperative Oncology Group (ECOG) performance status score. Discussion: This study investigates the synergistic mechanisms of integrated traditional Chinese and Western medicine in treating advanced GC, aiming to provide scientific evidence for the clinical application and further optimization of treatment strategies for GCPM. Conclusion: This study will evaluate the efficacy and safety of XTSJ decoction combined with trastuzumab and chemotherapy in patients with GCPM through a randomized controlled trial, providing evidence-based basis for the integrated treatment of traditional Chinese and Western medicine.