VEGFA and neoplasm: As for the morphological characteristics of primary renal lesion and their changes during therapy, the best therapeutic efficacy among naïve unresectable mRCC patients can be expected when the baseline size of a primary renal lesion tumor is smaller (hazard ratio [HR] = 0.903, p = 0.002) with a smaller necrotic portion (HR = 1.038, p = 0.168) and a higher attenuation number (HR = 0.936, p = 0.002); these parameters signify a small tumor cell density with high vascularity, making systemic therapy (especially with vascular endothelial growth factor-targeting agents) ideal.