This study analyzed the association between polymorphisms MMP-2 rs243865 (C-1306T), rs2285053 (C-735T), and MMP-9 rs3918242 (C-1562T) with serum concentrations of these enzymes in upper tract urothelial cancer (UTUC) patients. Here, MMP9 is linked to renal pelvis/ureter urothelial carcinoma.