As shown in the Table 2, depth of tumor invasion (HR, 1.28; 95% CI, 1.08–1.52; P = 0.004), lymph node metastasis (HR, 1.53; 95% CI, 1.33–1.76; P < 0.001), distant metastasis (HR, 2.55; 95% CI, 1.25–5.19; P = 0.009) and IL-13Rα2 expression (HR, 1.83; 95% CI, 1.38–2.43; P < 0.001) were all recognized as independent prognostic factors. Here, IL13RA2 is linked to metastasis.