Background: In advanced colorectal cancer, chemotherapy is usually administered without pauses and until progression but patients can experience cumulative toxicity and cannot tolerate a heavy therapeutic charge.
Aim: The aim of the present trial was to evaluate whether an intermittent chemotherapy with levo-leucovorin + 5-fluorouracil (5-FU) + irinotecan (CPT-11) was at least as effective as the same regimen given continuously, both administered until progression, in patients affected with advanced colorectal cancer and not previously exposed to chemotherapy for metastatic disease.
Patients, materials and methods: A total of 337 patients from 27 institutions were randomised between levo-leucovorin, 100/mg/m(2) i.v. + 5-FU; 400 mg/m(2) i.v. bolus + 5-FU; 600 mg/m(2) 22-h continuous infusion, days 1 and 2 + CPT-11; 180 mg/m(2) day 1, administered every 2 weeks 2 months on and 2 months off (arm A) and the same regimen administered continuously (arm B), until progression in both arms. The main end point was overall survival (OS), the secondary progression-free survival (PFS) and toxicity.
Results: At a median follow-up of 41 months, OS was 18 months in arm A and 17 months in arm B [hazard ratio (HR), 0.88]. Also PFS was comparable in the two groups (6 months in both, with HR, 1.03), and even grades 3-4 toxicity (mainly myelosuppression, fever and diarrhoea) was similar. Second-line oxaliplatin-based treatment was administered in a similar percentage (66%) in the two arms. The median chemotherapy-free period (drug holiday) in arm A was 3.5 months.
Conclusion: Reducing the charge of therapy in this population did not diminish the efficacy of treatment. Further studies with this strategy, including biologicals, are warranted.