Abstract. Background For many years, breast cancer has been the most common malignancy and the leading cause of female cancer mortality all over the world (1). According to the most updated report about burden of disease trends, cancers overall have increased by 34% during 199-2015 while breast cancer related deaths globally have increased to 45%, a much higher level than average overall cancers (1). In Taiwan, breast cancer has the highest incidence and is ranked as the fourth leading cause of mortality among Taiwanese women (2). From the viewpoint of epidemiology, the risk factors of breast cancer in Taiwan included high caloric intake, highfat diets, early menarche, late menopause, obesity, high levels of stress, and exposure to environmental pollutants (3). Since, the prevalence and mortality rates are both very high in Taiwan and the world, to figure out feasible molecular markers for early detection and prognosis prediction of breast cancer, especially the subtype of triple negative breast cancer (TNBC), are in urgent need.The matrix metalloproteinases (MMPs), which are also called matrixins, are a group of enzymes involved in tumor progression such as proliferation, invasion and metastasis (4, 5). In the literature, there are a few papers indicating that some MMP polymorphic genotypes, especially those 487