Perioperative vs Postoperative Chemotherapy + Bevacizumab in Colorectal Cancer, Liver Mets

Overview

Early-stage colorectal cancer(CRC)is localized and resectable, but 20% of the patients have metastatic disease at the time of diagnosis and 50% of all patients eventually die of the disease. The most frequent site of colorectal metastases is the liver, which accounts for 30% to 60% of cases. In these patients, the extent of liver disease is the main determinant of survival. Hepatectomy is the only potentially curative therapy for colorectal liver metastases (CLM), but when traditional criteria for resectability were used, only 10% of patients were candidates for surgical resection. Although adjuvant systemic therapy after resection of primary colorectal tumors is well established, there are relatively few data on the use of postoperative therapy vs. surgery alone in patients who have undergone resection of liver metastases. In this trial, the absolute increase in the 3-year PFS rate with the addition of FOLFOX4 was a modest but significant 9% in patients who had resection (from 33% to 42%; P = .025). For improving survival in patients with CLM, several studies with biologic agents have been tried. The use of bevacizumab, a monoclonal antibody against vascular endothelial growth factor (VEGF), has resulted in increased response rates in patients with stage IV colorectal cancer and improved OS and PFS. In an ongoing phase II trial presented in ASCO 2008, in patients who were potentially curable through resection of liver metastases, perioperative treatment with capecitabine and oxaliplatin (XELOX) plus bevacizumab yielded an overall response rate of 73% with stable disease in 21% and a mean PFS of 27 months. Response to chemotherapy significantly correlated with a prolonged PFS (P \< .001). On the basis of these backgrounds, we designed a phase II study to compare the effectiveness of combination chemotherapy with perioperative or postoperative bevacizumab treatment in patients with CLM.