Targeting metastatic colorectal cancer - present and emerging treatment options

Metastatic colorectal cancer is a significant cause of morbidity and mortality in the US and around the world. While several novel cytotoxic and biologic therapies have been developed and proven efficacious in the past two decades, their optimal use in terms of patient selection, drug combinations, and regimen sequences has yet to be defined. Recent investigations regarding anti-epidermal growth factor receptor therapies include the comparison of single-agent panitumumab and cetuximab, the benefit of adding cetuximab to chemotherapy in the conversion therapy setting, the comparison of cetuximab and bevacizumab when added to first-line chemotherapy, and predictive biomarkers beyond KRAS exon 2 (codons 12 and 13) mutations. With respect to anti-vascular endothelial growth factor therapies, new data on continuing bevacizumab beyond disease progression on a bevacizumab-containing chemotherapy regimen, the addition of bevacizumab to triplet chemotherapy in the first-line setting, maintenance therapy with bevacizumab plus either capecitabine or erlotinib, the addition of aflibercept to chemotherapy, and regorafenib as monotherapy have emerged. Recent scientific and technologic advances in the field of metastatic colorectal cancer promise to elucidate the biological underpinnings of this disease and its therapies for the goal of improving personalized treatments for patients with metastatic colorectal cancer.