Survival Outcomes Following Combination of First-Line Platinum-Based Chemotherapy with S-1 in Patients with Advanced Gastric Cancer

SIMPLE SUMMARY: Regardless of recent advances in the understanding of cancer biology, gastric cancer remains one of the leading causes of death worldwide. The efficacy of tegafur/gimeracil/oteracil (S-1) combined with a platinum agent in the first-line setting in advanced gastric cancer has been previously demonstrated in randomized clinical trials. However, real-world data regarding S-1 and platinum compounds (oxaliplatin or cisplatin) in European patients remains limited. This retrospective study aimed to report on the efficacy, safety as well as dose intensity in a European population with advanced gastric cancer. Patients have received S-1 in combination with a platinum agent for six cycles of treatment. S-1 combination with oxaliplatin was associated with superior efficacy as compared to cisplatin. This study confirms that S-1 in combination with oxaliplatin in the first-line setting of advanced gastric cancer is a safe and effective treatment option in European patients. ABSTRACT: The efficacy of S-1 combined with a platinum agent in the first-line setting and in patients with advanced gastric adenocarcinoma has been previously demonstrated in randomized clinical trials. However, real-world data regarding S-1 efficacy in European patients remains limited. In the present study, we reviewed the data of a European cohort of patients with advanced gastric cancer treated with first-line therapy consisting of S-1 in combination with a platinum agent. Forty-eight patients (29 with locally advanced/inoperable and 19 with metastatic disease) were treated with S-1 plus oxaliplatin (33 patients) or S1 plus cisplatin (15 patients). The Cox regression analysis, adjusted with propensity score, indicated that the use of cisplatin as compared to oxaliplatin was associated with increased risk of death (HR 9.634, p = 0.000). Four SAEs (serious adverse events) GIII were recorded (1 fatigue, 1 neutropenia, 1 anemia, 1 diarrhea) in 3 patients. S-1 combination with a platinum agent in the first-line setting in European patients with advanced gastric cancer results to similar survival outcomes and toxicity with previously reported data from Asian populations. S-1 combination with oxaliplatin seems to be associated with superior efficacy as compared to cisplatin.