Which factors predict bowel complications in patients with recurrent epithelial ovarian cancer being treated with bevacizumab?

Background. Increased rates of bowel perforation in patients with recurrent epithelial ovarian cancer (EOC) treated with bevacizumab have been reported, but the risk factors for this association are uncertain. We sought to identify factors associated with bowel perforation and fistula formation in recurrent EOC patients treated with bevacizumab. Methods. A chart review of all patients treated with bevacizumab for recurrent EOC at a single institution was performed. Pertinent patient characteristics and treatment information were collected. Univariate logistic regression was performed to analyze multiple variables. Results. One hundred twelve patients who were treated with 160 different bevacizumab regimens were identified. The median age was 60 years (range, 29–78 years). Patients had received a median of 4 prior chemotherapy regimens (range, 1–10). The median number of cycles was 4 (range, 0.5–31). Ten patients (9%) were diagnosed with bowel perforations, and another 2 patients (1.8%) were diagnosed with fistulas. The 30-day mortality following perforation was 50%, with 30% of patients dying within 1 week. Patients with rectovaginal nodularity were more likely to develop a bowel perforation or fistula than those who did not have this finding, OR=3.64 (95% CI=1.1 to 12.1, p =0.04). None of the other variables were significantly associated with bowel perforations or fistula formation. Conclusions. Rectovaginal nodularity is associated with an increased risk of bowel perforation or fistula formation for patients with recurrent EOC treated with bevacizumab. Careful consideration should be given prior to initiating bevacizumab treatment in EOC patients with rectovaginal nodularity since the mortality rate with bevacizumab associated bowel perforations is 50%.