The Effects of Preoperative Bevacizumab on Perioperative Complications in Patients With Tumor Undergoing Unexpected Operation

Avastin (bevacizumab) is a recombinant humanized monoclonal IgG1 antibody that binds to and inhibits the biologic activity of human vascular endothelial growth factor(VEGF) in in vitro and in vivo assay systems. Bevacizumab was first granted marketing approval in the United States on 26 February 2004 (international birth date) in combination with IV 5-fluorouracil(5-FU) based chemotherapy for the first-line treatment of patients with metastatic carcinoma of the colon or rectum (CRC). At present, bevacizumab is widely used in the treatment of solid tumors such as lung cancer ,colorectal cancer and so on. It has been reported in the literature that bevacizumab may adversely affect wound healing. To prevent postoperative complications, some guidelines state that the interval time between last dose of bevacizumab and operations should be at least 6 weeks, but the optimal time to discontinue bevacizumab before surgery has not been confirmed. This project aims to evaluate the risk of perioperative complications in cancer patients with a history of bevacizumab use within 6 weeks prior to unexpected operation.

This is a nationwide multicenter,retrospective,observational real-world study.The study will collect the medical records and prognosis in 30 days following surgery of patients with colorectal cancer and lung cancer who underwent unexpected operation within 6 weeks (including 6 weeks) of bevacizumab discontinuation from 01 Jan 2010 to 31 Dec 2019.All enrolled subjects aged 18-90 years old; Complete clinical data related to important indicators, including preoperative baseline data, surgical information and perioperative prognosis information. The patients who used anti-angiogenic agents other than bevacizumab within 6 weeks prior to surgery would be excluded.

Primary Evaluation Measures: To assess the risk of perioperative complications in patients with tumor who received bevacizumab prior to unexpected operation:to calculate the total incidence of perioperative complications in patients undergoing unexpected surgery after discontinuation of bevacizumab, including wound healing complications, non-wound-related infections, postoperative bleeding, thrombosis, gastrointestinal perforation, anastomotic leakage, secondary surgery, death and other perioperative adverse events;to calculate the incidence of each perioperative complication in patients undergoing unexpected operation after bevacizumab discontinuation.

SAS9.4 statistical analysis software will be used for analysis. Measurement indicators will be statistically described using number of cases, mean, median, standard deviation, minimum and maximum; categorical indicators will be statistically described using frequency and percentage. Unless otherwise specified, all statistical tests will adopt the two-sided test with α = 0.05, and the corresponding OR value and two-sided 95% confidence interval will be provided if applicable.