Univariate Cox regression analysis revealed that gender, therapies for ESCC before the development of fistula, the type of esophageal fistula, the treatment of esophageal fistula and the Hb level were prognostic factors of post-fistula survival time (P<0.05) (Table 2). Here, GSTM1 is linked to esophageal squamous cell carcinoma.