Preliminary investigation of MMP8 (rs11225395) and MMP9 (rs3787268) polymorphisms association with breast cancer risk in pashtun women of Pakistan

Background: Single Nucleotide polymorphisms (SNPs) in MMP8 and MMP9 have been widely associated with breast cancer risk in different ethnicities with inconsistent results. There is no such study conducted so far in the Pashtun population of Khyber Pakhtunkhwa, Pakistan. Therefore, this study was conducted to check MMP8 (rs11225395) and MMP9 (rs3787268) polymorphism with breast cancer risk in the selected population.

Methods: This study, consisting of 300 breast cancer patients and 168 gender and age-matched healthy controls was subjected to confirm MMP8 and MMP9 polymorphisms. Clinicopathological data and blood samples were taken from all the participants. DNA was extracted and SNPs were confirmed using the T-ARMS-PCR protocol.

Results: Based on our study results, significant associations were observed between the MMP8 rs11225395 risk allele (G) and increased breast cancer risk, with the G allele frequency higher in patients (65%) compared to controls (51%) (OR = 1.752, 95% CI = 1.423-3.662, p = 0.002). Genotypes GG (OR = 4.218, p = 0.005) and AG (OR = 7.286, p = 0.0001) of MMP8 rs11225395 were also significantly associated with elevated breast cancer risk. Similarly, MMP9 rs3787268 exhibited a higher frequency of the risk allele (A) in breast cancer cases (81%) compared to controls (41%), correlating strongly with increased risk (OR = 6.320, p = 0.0001). Genotypes AA (OR = 14.500, p = 0.0001) and AG (OR = 2.429, p = 0.077) of MMP9 rs3787268 containing the risk allele showed significant associations with heightened breast cancer risk. Subgroup analyses based on age, disease progression, tumor size, and grade revealed noteworthy associations for both MMP8 rs11225395 and MMP9 rs3787268. MMP8 rs11225395 genotypes displayed significant correlations with age (p = 0.066), disease progression (p = 0.0001), larger tumor size (p = 0.005), and higher tumor grade (p = 0.006). Similarly, MMP9 rs3787268 genotypes were significantly associated with age (p = 0.001), disease progression (p = 0.010), larger tumor size (p = 0.018), and higher tumor grade (p = 0.037). Logistic regression analyses further underscored these genetic variants' potential role as biomarkers in breast cancer, particularly in relation to specific hormone receptor statuses such as estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) positivity.

Conclusion: The results revealed significant associations between the mutant alleles and genotypes of MMP8 (rs11225395) and MMP9 (rs3787268) with increased breast cancer risk in the Pashtun population of Khyber Pakhtunkhwa, Pakistan. However, more investigation will be required on large data sets to confirm the selected SNPs and other SNPs in the selected and other related genes with the risk of breast cancer.