A combined analysis demonstrated that the addition of glutamate, 12-hydroxyeicosatetraenoic acid, β-hydroxybutyrate, coagulation factor V, and matrix metalloproteinase-1 to cancer antigen 15-3 (CA15-3) values, a widely used serum marker in BC, permitted accurate discrimination when comparing non-malignant breast disease and BC at different stages. This evidence concerns the gene MMP1 and breast cancer.