The 5A/6A polymorphism of the matrix metalloproteinase 3 gene promoter and breast cancer

Purpose: The matrix metalloproteinase 3 (MMP3), also known as stromelysin-1, is a key-player for carcinogenesis and tumor growth. A 5A/6A promoter polymorphism is associated with differences in MMP3 activity and has been linked to cancer susceptibility in some studies. In the present study we evaluated the role of this polymorphism for breast cancer risk. Experimental Design: A case-control study was performed including 500 patients with histologically confirmed breast cancer and 500 female, age-matched, healthy control subjects from population-based screening studies. The MMP3 5A/6A polymorphism was determined by a 5'-nuclease (TaqMan) assay. Results: Prevalences of 5A/5A, 5A/6A, and 6A/6A genotypes were similar among patients (20.6, 51.8, and 27.6%, respectively) and controls (23.3, 47.3, and 29.4%, P = 0.34). The odds ratio of carriers of a MMP3 5A allele for breast cancer was 1.09 (95% confidence interval, 0.83-1.44). Patients with the 5A/5A genotype had a higher proportion of lymph-node metastases than those with a 5A/6A or 6A/6A genotype (P = 0.010). Conclusions: The MMP3 5A/6A promoter polymorphism does not appear to influence breast cancer susceptibility but may be linked to a higher risk for metastasizing among breast cancer patients.