Analysis of fistula formation of T4 esophageal cancer patients treated by chemoradiotherapy

Background and aim Fistula is one of the known complications of T4 esophageal cancer (T4-EC). The standard treatment for T4-EC is chemoradiotherapy, but detailed data about fistula resulting from chemoradiotherapy in this condition are limited. In particular, radiographic findings of T4-EC with fistula have not been reported. This study assessed the risk factors of fistula based on clinical information on patients with chemoradiotherapy for T4-EC. Methods We retrospectively reviewed the clinical data of 59 T4-EC patients who had squamous cell carcinoma without any fistula before receiving definitive or palliative chemoradiotherapy. Results A fistula was observed in 18 patients (31%) throughout their clinical course. The overall survival in the fistula group was significantly shorter than that in the non-fistula group (259 vs. 346 days; p = 0.0341). The axial tumor size on computed tomography (CT) was confirmed as an independent risk factor for esophageal fistula in multivariate analysis of stepwise methods [OR 1.226; 95% CI 1.109–1.411; p < 0.0001]. Twelve out of 14 patients with an axial tumor size of 50 mm or greater had developed a fistula. Conclusions A large tumor size on the axial plane on CT is a risk factor for fistula formation.