Evolving role of antineoplastic agents in colorectal cancer

The epidemiology, natural history, patient presentation, staging, prognosis, and treatment of colorectal cancer are described.

Colorectal cancer is a common malignancy that usually is not diagnosed when it is localized because it typically is asymptomatic in the early stages. Various cancer chemotherapeutic agents with different toxicities are available, including the recently introduced recombinant humanized immunoglobulin G(1) monoclonal antibodies cetuximab and bevacizumab. Chemotherapy may be used with or without surgery in patients with advanced or metastatic colorectal cancer, usually for palliation rather than a cure. The results of clinical trials suggest that patients with advanced or metastatic colorectal cancer probably should receive 5-fluorouracil (5-FU)/leucovorin, irinotecan, oxaliplatin, bevacizumab, and cetuximab at some time in the course of treatment, although the preferred combinations and sequence of these agents remain to be determined. After surgery, adjuvant chemotherapy may be used for curative purposes in patients with stage III disease and some patients with stage II disease at high risk for disease recurrence and death. Although 5-FU plus leucovorin has been the standard adjuvant therapy, clinical trials have demonstrated that adding oxaliplatin or using capecitabine alone instead is an alternative.

Several recently introduced chemotherapeutic agents appear promising for the treatment of colorectal cancer, but additional clinical research is needed to identify the ideal combinations and sequence of these agents.