Alternating XELFOX and XELFIRI in patients with metastatic colorectal cancer

Background: To evaluate the antitumor activity and toxicity of 5-fluorouracil (FU)/leucovorin (LV) and capecitabine (C) given with either oxaliplatin (OX) or camptothecin (CPT-11) in the treatment of chemotherapy naive patients with metastatic colorectal cancer. Materials and Methods: The outpatient treatment, consisted of 2 consecutive days of LV, 200 mg/m2, 5-FU 400 mg/m2, and C 2000 mg/m2 that, in one cycle, was preceded by 2 days of OX 50 mg/m2, and, in the subsequent cycle, by CPT-11, 90 mg/m2. Results: All 54 patients were assessable for toxicity and response. Thirty-two patients responded, giving an overall response rate of 59.3%. Median progression-free survival was 12.3 months and median survival was 20.5 months. Toxicity included grade 3 to 4 neutropenia in 43% of patients, grade 3 diarrhea in 7% of patients, and grade 2 neurotoxicity in 6% of patients. Conclusions: The alternating, bimonthly schedule of OX and CPT-11 plus 5-FU/LV/C has substantial antitumor activity and is well tolerated.