Effectiveness of neoadjuvant chemotherapy with a docetaxel, cisplatin, and S-1 (DCS) regimen for T4b gastric cancer

Abstract Background No studies on neoadjuvant chemotherapy for gastric cancer (GC) with T4b stage were reported. This study aimed to assess the effectiveness of neoadjuvant chemotherapy using DCS regimen (docetaxel, cisplatin, and S-1) for GC with T4b stage. Methods Forty-three patients diagnosed GC with surgical or clinical T4b stage received three or four preoperative cycles of DCS therapy followed by gastrectomy and lymphadenectomy between Jan-2018 and Dec-2022. Short-tern outcomes including tumor response, completion of neoadjuvant chemotherapy, toxicity and adverse events, rate of treatment-related death, R0 resection, rate of complete adjuvant chemotherapy and short-term surgical results were investigated. The oncologic outcomes comprised 3-year OS and 3-year disease-free survival (DFS). Results A total of 43 patients with T4b gastric cancer were included in the analysis. Among them, twenty-five patients underwent gastrectomy and lymphadenectomy. The completion rate of neoadjuvant chemotherapy was 88.4%, including 4 cycles of 51.2% and 3 cycles of 37.2%. The disease-control and clinical response rate were 88.4% and 58.1%, respectively. During preoperative chemotherapy, grade 3/4 neutropenia occurred in 20.9%, anemia in 13.9%, hyponatremia in 4.8%, and vomiting in 2.3%. Pathologic complete response was achieved in 8.0%. After surgery, no patient experienced severe complications (Clavien Dindo > = 3). The R0 resection rate was 72.0% and the rate of complete adjuvant chemotherapy was 83.3%. The 3-year OS and DFS rates were 49% and 38%, respectively. Conclusions Neoadjuvant chemotherapy with DCS regimen demonstrated a high tolerance, high tumor response rate, high complete adjuvant chemotherapy rate and satisfactory 3-year survival outcomes. Three- or four-course of preoperative DCS regimen is a promising approach for GC with T4b stage.