New systemic frontline treatment for metastatic colorectal carcinoma

Abstract

Options for first-line chemotherapy in patients with metastatic colorectal carcinoma have broadened considerably with the introduction of irinotecan and oxaliplatin. Furthermore, the oral fluoropyrimidine capecitabine has demonstrated efficacy in Phase III trials and recently was approved for first-line treatment in Europe and the United States. Capecitabine yielded similar median times to disease progression and median survival rates compared with bolus 5-fluorouracil (5-FU)/leucovorin (LV) (Mayo Clinic/North Central Cancer Treatment Group regimen), with superior and similar response rates, respectively. However, its role as a first-line, single-agent substitute for intermittent infusional 5-FU/LV remains to be defined. The addition of irinotecan or oxaliplatin to 5-FU/LV resulted in improved response rates and progression-free survival in large, randomized trials; moreover, irinotecan-containing regimens resulted in improved overall survival. Prevalent regimens of irinotecan/5-FU/LV and oxaliplatin/5-FU/LV have been compared in two randomized Phase III trials. One study demonstrated the statistical superiority of oxaliplatin/infusional 5-FU/LV over irinotecan/bolus 5-FU/LV in terms of response, time to disease progression, and median survival; however, those advantages may have been attributable to infusional administration or to major differences in second-line therapy. A randomized Phase III study comparing irinotecan and oxaliplatin in combination with the same infusional 5-FU/LV regimens and crossover in case of disease progression showed equivalent efficacy for both schedules in the first-line setting, but the irinotecan combination proved beneficial in terms of safety. New molecular targeted agents, such as angiogenesis-modulating compounds (e.g., bevacizumab) and epidermal growth factor receptor inhibitors (e.g., cetuximab), are under clinical investigation. This review updates current systemic frontline treatments and future perspectives for patients with advanced colorectal carcinoma.