S-1 in Patients with Advanced Esophagogastric Adenocarcinoma: Results from the Safety Compliance Observatory on Oral fluoroPyrimidines (SCOOP) Study

BACKGROUND AND OBJECTIVES: S-1-based regimens have been shown to be as effective as other fluoropyrimidine-based regimens with a better safety profile in patients with advanced esophagogastric adenocarcinoma. However, real-world data on S-1 in European patients with advanced esophagogastric adenocarcinoma are lacking. The Safety Compliance Observatory on Oral fluoroPyrimidines (SCOOP) study evaluated safety and relative dose intensities for patients treated with S-1-based regimens for advanced esophagogastric adenocarcinoma as part of daily practice. METHODS: Overall, data for 125 patients with advanced esophagogastric adenocarcinoma were collected at 21 centers in five countries in Europe. Demographics, treatment, and adverse-event data were recorded over a planned treatment of six cycles. RESULTS: Most patients (87%) received combination treatment of S-1 plus a platinum compound. Adverse events related to S-1 treatment were mostly grade 1 or 2 while reported grade 3–4 serious adverse events related to S-1 occurred in 12 patients and were most often grade 3 neutropenia (n = 4, 3.2%) or diarrhea (n = 5, 4%). The most common adverse events of any grade that were attributable to S-1 treatment included neutropenia, anemia, thrombocytopenia, diarrhea, nausea, vomiting, and fatigue. No patients experienced mucositis, dehydration, or febrile neutropenia, whereas 2% (3/125) of patients experienced hand-foot syndrome. CONCLUSION: The overall relative dose intensity was 70%. In a real-world setting, patients with advanced esophagogastric adenocarcinoma tolerated S-1 treatment well with high compliance rates. The SCOOP study provides valuable information on S-1 relative dose intensity that can be used for treatment decision making.