Univariate analysis of OS revealed that differentiation type (undifferentiated type, p < 0.0001) in primary tumors and H class (2.3, p = 0.0400), grade (B.C, p = 0.0119), and HIF-1α expression (positive, p = 0.0220) in metastatic tumors were significant prognostic factors (Table 3). This evidence concerns the gene HIF1A and metastatic neoplasm.