OGDH and neoplasm: To evaluate the discriminating potential of the succinate-related pathway for locoregional disease-free survival, we used the CRT method, first inputting the clinico-pathological variables (ECOG index, N-category, stage, BMI, treatment, tumor location and differentiation), and then the circulating succinate levels and the tumor gene expression of HIF-1α, SDHA, SDHB, OGDH and SUCNR1 as independent variables.