The risk of gastrointestinal perforation and/or fistula in patients with recurrent ovarian cancer receiving bevacizumab compared to standard chemotherapy: a retrospective cohort study.

OBJECTIVE: To determine the rate of gastrointestinal perforation and/or fistula in patients with recurrent ovarian cancer treated with and without bevacizumab.

METHODS: A retrospective chart review from January 2004 to August 2007 identified two cohorts of patients with recurrent ovarian cancer: 1) patients who were receiving bevacizumab either alone or in combination with standard chemotherapy; 2) patients who were receiving standard chemotherapy alone. Gastrointestinal toxicity (perforation and fistula) was assessed using NCI Common Toxicity Criteria. Relative risk and 95% confidence intervals were calculated. Chi square test and student's t test were used for statistical analysis.

RESULTS: Sixty-eight patients receiving bevacizumab for recurrent ovarian cancer were identified. 67% of these patients received chemotherapy in combination with bevacizumab. For comparison, 195 patients receiving standard chemotherapy alone for recurrent ovarian cancer were identified. A history of previous gastrointestinal resection (40% vs. 37%; p=0.79) and gastrointestinal obstruction (30% vs. 27%; p=0.74) was similar in both cohorts. Five patients (7.2%) developed a gastrointestinal perforation and/or fistula in the bevacizumab cohort compared to 13 patients (6.5%) in the chemotherapy alone cohort. The relative risk for developing a perforation and/or fistula is 1.09 (95% CI, 0.40 to 2.96).

CONCLUSIONS: Although a substantial number of patients with recurrent ovarian cancer experience gastrointestinal obstruction, the rate of gastrointestinal perforation and/or fistula is relatively low. Treatment with bevacizumab does not significantly increase gastrointestinal toxicity compared to standard salvage chemotherapy.