Bevacizumab Timing Before Surgery
Bevacizumab must be discontinued at least 6 weeks before any elective surgery, and this applies to all doses including the 3rd dose. 1
Critical Timing Requirements
Pre-Surgical Interval
- The minimum interval between the last bevacizumab dose and elective surgery is 6 weeks 1
- This 6-week interval corresponds to approximately 2 half-lives of bevacizumab (terminal half-life ~20 days) 1, 2
- For interval debulking surgery specifically, bevacizumab should be withheld for 6 weeks before the procedure 1
Post-Surgical Resumption
- Bevacizumab should not be reinitiated until at least 6-8 weeks postoperatively 1
- This delay is necessary to ensure adequate wound healing 1
Clinical Rationale
Wound Healing Complications
The strict timing requirements exist because bevacizumab significantly interferes with wound healing 1. Clinical trial data demonstrate:
- When bevacizumab was administered during major surgery, wound healing complications occurred in 13% of patients versus 3.4% with chemotherapy alone (P=0.28) 1
- However, when bevacizumab was stopped at least 6 weeks before surgery, wound healing complications dropped to only 1.3% versus 0.5% with chemotherapy alone (P=0.63) 1
Additional Surgical Risks
- Increased risk of gastrointestinal perforation, particularly in patients with extensive prior intra-abdominal surgery 1
- Risk of necrotizing fasciitis (sometimes fatal), usually secondary to wound healing complications, GI perforation, or fistula formation 1
Dosing Schedule Context
Bevacizumab is typically administered every 2 weeks in colorectal cancer regimens 1. Given this schedule:
- If surgery is planned, calculate backward from the surgical date
- The 3rd dose timing depends entirely on when surgery is scheduled
- If the 3rd dose would fall within 6 weeks of planned surgery, it must be omitted or the surgery delayed 1
Common Pitfall
Do not administer bevacizumab closer than 6 weeks to surgery simply because it is "only the 3rd dose" - the wound healing risk is related to the drug's presence in the system (half-life ~20 days), not the cumulative number of doses received 1, 2.