Oncologists Current Opinion on the Treatment of Colon Carcinoma

Abstract

Colorectal cancer is a major global health problem with more than a million new cases diagnosed worldwide in 2005. In the United States, this malignancy is the third most common with 145,000 new cases and the second most lethal with 56,000 deaths in 2005. Unfortunately, preclinical diagnostic screening in the U.S. population is less than 30-40 percent. The last decade has ushered in exciting new advances for medical oncologists caring for patients with colorectal cancer. The older cytotoxic chemotherapy drug 5-fluorouracil underwent new formulation, and two new drugs, oxaliplatine and irinotecan, were investigated as adjunctive therapies. Finally, targeted therapies, including monoclonal antibodies against vascular endothelial growth factor (bevacizumab) and the epidermal growth factor receptor (cetuximab), are now standard treatment for metastatic colorectal carcinoma. Systemic adjuvant chemotherapy can be lifesaving in patients with locally advanced colorectal carcinomas, which represent 60-70 percent of cases. For patients with metastatic colorectal cancer, the survival rate has doubled. With more effective drugs in the therapeutic armamentarium, new controversies have arisen. Questions regarding the best schedules for classical cytotoxic chemotherapy were largely answered by contemporary clinical trials. The potential of molecular genetic markers for prognosis or prediction of drug-specific toxicity and efficacy have been explored, but their utility for clinical practice is still being investigated. We will review the rapidly changing, state-of-the-art combination chemotherapy for adjuvant and metastatic disease. We will discuss in detail the c-ERBB family of tyrosine kinases as therapeutic targets in colorectal cancer.