Late anastomotic colonic dehiscence due to antiangiogenic treatment, a specific drug-class complication requiring specific treatment: an example of pazopanib complication.

Bevacizumab, a recombinant humanized monoclonal antibody against vascular endothelial growth factor (VEGF), was the first angiogenesis inhibitor approved for the first-line treatment of metastatic colorectal cancer in combination with intravenous fluorouracil-based chemotherapy. Two major cohort studies--BRiTE and BEAT--reported a 2% incidence of bowel perforation, which remains a rare, but serious, complication of bevacizumab treatment. Late anastomotic complications, arising > 3 months after surgery, are emerging occurrences that may be associated with bowel perforation. We report here on such a case caused by pazopanib, a new antiangiogenic agent, and also include a review of the published cases in the literature (n = 23) and an analysis of their management. Proctectomy was the initial surgery in 17 patients (74%) with rectal cancer, and 13 of these patients had undergone adjuvant radiation prior to surgery. The majority (84%) of the complications occurred with antiangiogenic treatment after a mean number of four cycles. Patients' management was invariably associated with withdrawal of the antiangiogenic agent, together with conservative treatment in 14 patients (66%).