Irinotecan combined with 5-fluorouracil and leucovorin third-line chemotherapy after failure of fluoropyrimidine, platinum, and taxane in gastric cancer: Treatment outcomes and a prognostic model to predict survival

Background: The aim of this study was to evaluate the activity and safety of the combination chemotherapy of 5-fluorouracil (5-FU), leucovorin, and irinotecan (FOLFIRI regimen) after failure of fluoropyrimidine, platinum, and taxane in gastric cancer (GC) and to evaluate the prognostic factors for survival. Methods: Patients received biweekly FOLFIRI chemotherapy as third-line treatment. The FOLFIRI-1 consisted of irinotecan (180 mg/m² in a 2-h infusion) on day 1, and then leucovorin (200 mg/m² in a 2-h infusion) and 5-FU (a 400 mg/m² bolus, followed by 600 mg/m ² in a 22-h continuous infusion) on days 1 and 2. FOLFIRI-2 consisted of irinotecan (180 mg/m² in a 2-h infusion) on day 1, and then leucovorin (400 mg/m² in a 2-h infusion) and 5-FU (a 400 mg/m ² bolus, followed by 2400 mg/m² in a 46-h continuous infusion) on day 1. Results: A total of 158 patients were included. The overall response rate was 9.6 % in patients with measurable lesions. The median progression-free survival (PFS) and overall survival (OS) were 2.1 months [95 % confidence interval (CI), 1.7-2.5] and 5.6 months (95 % CI, 4.7-6.5), respectively. The major grade 3/4 toxicity was myelosuppression (36.7 %). Good performance status (PS), fewer metastatic sites, and longer duration from the first-line to third-line chemotherapy were independent prognostic factors affecting both PFS and OS. Conclusions: The FOLFIRI regimen showed antitumor activity and tolerable toxicity profiles against advanced GC in the third-line setting. Patients with good PS, fewer metastatic sites and longer previous treatment duration might have the maximal benefit from third-line chemotherapy.