Posted online April 8, 2013 on www.jco.org .
New findings from a clinical trial in patients with colorectal cancer and inoperable metastases in the liver (cancer that has spread from the colon or rectum to the liver) suggest that combination treatment with standard therapy and targeted drug cetuximab (Erbitux) caused significant shrinkage of metastases, making successful surgery feasible. Patients who received cetuximab in addition to traditional chemotherapy lived markedly longer than those who received only chemotherapy.
Many patients with advanced colorectal cancer experience cancer spread to the liver, and removal of these liver tumors offers the best chance for long-term survival for these patients. However, only 10 -20 percent of patients with liver metastases are initially a candidate for surgery.
Such surgery can be curative, and is generally critical to long-term survival. While cetuximab and chemotherapy combination is a standard treatment option for many patients with advanced colorectal cancer, this is the first study to explore its impact on inoperable liver metastases.
In the study, conducted in China, 138 patients with advanced colorectal cancer were randomly assigned to receive either chemotherapy and cetuximab or only chemotherapy. They received either the FOLFIRI (leucovorin, fluorouracil and irinotecan) or the mFOLFOX6 (leucovorin, fluorouracil, and oxaliplatin) chemotherapy drug combination. Overall, patients who received cetuximab and chemotherapy lived longer compared with those who received only chemotherapy (31 versus 21 months median survival).
Following treatment with cetuximab and chemotherapy, about 25 percent of patients who initially had inoperable tumors in the liver (metastases) were able to have those tumors successfully removed. In contrast, among patients who had been treated with chemotherapy alone, only 7 percent were candidates for liver surgery following treatment. Among patients treated with cetuximab and chemotherapy, those who underwent successful surgery lived much longer (46 versus 26 months median survival) compared to patients who were not able to have surgery.
What This Means for Patients
Colorectal cancer is the third most common cause of cancer death among men and women in the United States. The findings of this study suggest that patients with colorectal cancer and inoperable metastasis in the liver may experience significant improvements in the length and quality of life from combination treatment with cetuximab and standard chemotherapy.
This treatment combination has the potential to shrink liver metastases rendering them amenable to surgical removal and thus offering patients the prospect of long-term survival. The study also provides strong evidence that cetuximab has a life-prolonging effect even for patients whose tumors remain inoperable.
Cetuximab benefits only those patients with colorectal cancer who do not have alterations in a gene called KRAS. ASCO recommends  that patients with metastatic colorectal cancer have their tumors tested for KRAS mutations, so that doctors can give their patients the most effective treatment and not expose patients to unnecessary side effects.
Guide to Colorectal Cancer  
Understanding Chemotherapy