The role of chemotherapy in stage IV colorectal cancer: Focus on combinations with biologic agents and conversion therapy

Recent findings in studies of chemotherapy in metastatic colorectal cancer include the apparent ability of the presence of mutated K-ras to predict the absence of response to epidermal growth factor receptor (EGFR) inhibitors, the lack of benefit of combining panitumumab and bevacizumab in first-line treatment, the benefits of maintenance therapy versus chemotherapy-free intervals, and the suggested benefit of continuing bevacizumab treatment beyond first disease progression. In the setting of liver metastases, recent data indicate a reduced risk of disease progression with perioperative chemotherapy in patients with resectable disease (albeit at the cost of increased postoperative complications) and potential roles for chemotherapy and biologic therapy in converting initially unresectable disease to resectable disease.