Impact of bevacizumab on functional recovery and histology of the liver after resection of colorectal metastases

Background: The impact of bevacizumab on functional recovery and histology of the liver was evaluated in patients undergoing hepatic resection for colorectal liver metastases (CLM) following bevacizumab treatment. Methods: Consecutive patients who had resection of CLM between July 2005 and July 2009 following preoperative chemotherapy were identified retrospectively from a prospectively collected database. Patients who had received bevacizumab before the last chemotherapy line were excluded. Postoperative liver function and histology were compared between patients with and without bevacizumab treatment. Recorded parameters included serum prothrombin time, total bilirubin concentration, and levels of aspartate and alanine aminotransferase and gamma-glutamyltransferase. Results: Of 208 patients identified, 67 had received last-line bevacizumab, 44 were excluded and 97 had not received bevacizumab. Most patients in the bevacizumab group (66 per cent) received a single line of chemotherapy. Bevacizumab was most often combined with 5-flurouracil/leucovorin and irinotecan (68 per cent). The median number of bevacizumab cycles was 8.6 (range 1-34). Bevacizumab administration was stopped a median of 8 (range 3-19) weeks before surgery. There were no deaths. Postoperative morbidity occurred in 43 and 36 per cent of patients in the bevacizumab and no-bevacizumab groups respectively (P = 0.353). The mean(s.d.) degree of tumour necrosis was significantly higher in the bevacizumab group (55(27) versus 32(29) per cent; P = 0.001). Complete pathological response rates were comparable (3 versus 8 per cent; P = 0.307). Postoperative changes in functional parameters and objective signs of hepatic toxicity were similar in both groups. Conclusion: Preoperative administration of bevacizumab does not seem to affect functional recovery of the liver after resection of CLM. Tumour necrosis is increased following bevacizumab treatment.