Background: Metastatic breast cancer is a cancer which grows and develops in other tissues or organs with the nature and type of cancer similar to its origin. The prevalence of metastatic breast cancer is quite high increase in the overall incidence rate of approximately 1.5% per year. Cancer metastatic is one of the factors increasing mortality and morbidity in patients with a low cure rate (30%).  Evidence suggests that breast cancer is affected by genetics and non-genetics (epigenetic). Gene promoter polymorphisms of  MMP-9 is one of the genetic factors that play a role in breast cancer metastatic. This research was conducted with the aim of whether the polymorphism C-1589T and G-1665A on MMP-9 gene promoter and high levels are a risk factor for breast cancer metastatic.  Methods: This research has been done with cross sectional and case control study. Sixty six patient of breast cancer devided in two groups, thirty three with metastatic used as a samples and thirty three without metastatic used as a controls.  PCR and sequencing techniques were used to presence of polymorphism and ELISA techniques used to determined levels of MMP-9 enzyme. Results: The research found C-1589T polymorphism (genotype-CT) and G-1665A (genotype-GA) and also with both genotype-CT and genotipe-GA (genotype-CT/GA). Genotypes were found to be associated with the occurrence of breast cancer by 51%.  C-1589T polymorphism (genotype-CT) and G-1665A polymorphism (genotype-GA) increased levels of MMP-9 but were not risk factor for breast cancer metastatic (OR= 1.61; 95% CI= 0.41-6.34; p= 0.367) and (OR= 1.86; 95%CI= 0.62-5.61; p= 0.204). While polymorphism with both genotype (genotype-CT/GA) increasing levels of MMP-9 and indicated risk factor for breast cancer metastatic (OR= 8.62; CI95%= 0.99-74.57: p=0.027). Conclusions: Polymorphism with genotype-CT, genotype-GA and genotype-CT/GA found about 51% on breast cancer Balinese Tribe.  Enzyme levels found to be higher in cases than in controls but not significantly different. Polymorphism with genotype-GA and genotype-CT increase levels of MMP-9 enzyme but not as risk factor for metastatic cancer while genotype-CT/GA increases levels of the enzyme MMP-9 and as a risk factor for breast cancer metastatic in Balinese Tribe. Â
