Efficacy and Tolerability of Oxaliplatin Plus Irinotecan 5-Fluouracil and Leucovorin Regimen in Advanced Stage Colorectal Cancer Patients Pretreated With Irinotecan 5-Fluouracil and Leucovorin

Abstract

Oxaliplatin has been introduced in the treatment of advanced colorectal cancer during the past few years. The pre-existing treatment of leucovorin-5-fluorouracil-irinotecan (IFL), although reasonably effective, has needed novel, active agents to increase the response rate and overall survival. We planned this phase 2 study in patients pretreated with IFL, adding oxaliplatin as second-line treatment: our objectives were to determine response rate and overall survival. All patients (median age 65) were designated to receive 6 cycles of chemotherapy: leucovorin 200 mg/m2 infused for 60 minutes, 5-fluorouracil 500 mg/m2 bolus at 30 minutes from the start of the previous infusion, irinotecan 135 mg/m2 infused for 90 minutes, and oxaliplatin 135 mg/m2 for 90 minutes, infused sequentially on day 1 and repeated every 3 weeks. Standard ondansetron antiemetic treatment and dexamethasone 8 mg were administered to all patients. No prophylactic recombinant human granulocyte colony-stimulating factor was permitted. Fifty-seven patients were recruited and 54 were evaluable for response, survival, and toxicity. All patients had advanced, inoperable, metastatic disease in the liver and/or lungs, abdominal cavity, and multiple sites. All patients had undergone IFL pretreatment and had no response; 40 had disease progression and 14 had stable disease when entering the present study; 302 chemotherapy cycles (mean 5.92) were administered. There was no treatment delay caused by toxicity (either neutropenia or diarrhea). Irinotecan and oxaliplatin were reduced by 25% in 6 (11.1%) patients. No complete responses were observed; 21 (38.9%) patients achieved partial response, 26 (48.2%) had stable disease, and 7 (13%) had disease progression. Median duration of response was 6 months, time to tumor progression (TTP) 8 months, and median overall survival after the initiation of second-line treatment was 10 months (95% confidence interval [CI], 7.5-12.6). The addition of oxaliplatin to IFL as second-line treatment rendered a prolongation of survival and a response rate of 38.9% in patients in whom IFL pretreatment had failed.