The Effects of Preoperative Bevacizumab on Perioperative Complications

This is a nationwide multicenter,retrospective,observational real-world study. 1. To assess the risk of perioperative complications in patients with tumor who received bevacizumab prior to unexpected operation. 2. To assess the correlation of the interval time between the last dose of bevacizumab and operation and occurrence of perioperative complications. 3. To explore the risk factors of perioperative comlications in patients with tumor received bevacizumab prior to unexpected operation.