Significant Association of Matrix Metalloproteinase-9 Polymorphisms With Triple Negative Breast Cancer Risk

Matrix metalloproteinase-9 (MMP-9) has been associated with the development and progression of breast cancer (BCa). However, the relationship between MMP-9 genetic variants and BCa susceptibility remains contentious and inconclusive. This study aimed to evaluate the association of MMP-9 rs3918242 promoter polymorphisms with BCa, with a particular focus on the risk of triple-negative breast cancer (TNBC).

A case-control study was conducted involving 1,232 BCa patients and 1,232 healthy controls. The MMP-9 rs3918242 genotypes were determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis.

The genotype distribution of MMP-9 rs3918242 among the control group adhered to Hardy-Weinberg equilibrium (p=0.3265). No statistically significant differences were observed in the genotype frequencies between BCa cases and controls (p for trend=0.2555). Although the homozygous variant genotype (TT) showed a potential risk-increasing effect, this was not statistically significant [odds ratio (OR)=1.43, 95% confidence interval (CI)=0.88-2.36, p=0.1869]. Similarly, allele frequency analysis indicated no significant association between the variant T allele and overall BCa risk (OR=1.13, 95%CI=0.97-1.33, p=0.1265). Additionally, no interaction was detected between MMP-9 rs3918242 genotypes and the age of BCa onset (both p>0.05). Notably, the TT genotype of MMP-9 rs3918242 was significantly associated with an increased risk of TNBC (OR=2.49, 95%CI=1.32-4.72, p=0.0072).

The MMP-9 rs3918242 TT genotype may serve as a potential predictive biomarker for TNBC in the Taiwanese population.