Increased genitourinary fistula rate after bevacizumab in recurrent cervical cancer patients initially treated with definitive radiochemotherapy and image-guided adaptive brachytherapy

Background and purpose Patients with recurrent cervical cancer (RecCC) who received definitive radiochemotherapy including image-guided adaptive brachytherapy (IGABT) as primary treatment are currently treated in our institution with palliative intent by chemotherapy (CHT) combined with bevacizumab (BEV). We aim to evaluate the risk of gastrointestinal (GI)/genitourinary (GU) fistula formation in these patients. Materials and methods Data of 35 consecutive patients with RecCC treated initially with radiochemotherapy and IGABT were collected. Known and presumed risk factors associated with fistula formation were evaluated. Fistula rate was compared between patients receiving CHT or CHT+BEV. Results Of the 35 patients, 25 received CHT and 10 patients received CHT+BEV. Clinical characteristics were comparable. Fistulae were reported in 6 patients: two fistulae (8%) in the CHT group, four (40%) in the CHT+BEV group. GU fistula occurred in the CHT+BEV group only (3/4). Of these 6 patients with fistulae, 5 (83%) had undergone previous invasive procedures after the diagnosis of RecCC and 1 patient had undergone pelvic re-irradiation; 3/6 patients had developed a local recurrence. No other risk factors for fistula formation were identified. Conclusion In patients with RecCC after definitive radiochemotherapy including IGABT, the addition of BEV to CHT may increase the risk for GU fistula formation, particularly after invasive pelvic procedures. Future clinical studies are required to identify predictors for fistula formation to subsequently improve patient selection for the addition of BEV in the RecCC setting.