Genetic variants of the XRCC3 DNA repair gene: risk implications in breast cancer among Iraqi patients

Introduction:
Breast cancer is the predominant form of malignancy among women. Polymorphisms in DNA repair genes, such as X-ray repair cross complementing 3 (XRCC3), can influence an individual’s capability to repair damaged DNA. This can result in genetic instability and potentially contribute to the development of cancer. This study investigates the correlation between the XRCC3 Thr241Met genetic variants and the risk of breast cancer.

Material and methods:
This study is considered the first study in Iraq that sheds light on studying the effect of the XRCC3 Thr241Met genotype variants and their relationship with increased risk of breast cancer. The blood of 75 Iraqi women who had been diagnosed with breast cancer was used in this study to extract DNA, in addition to using 50 blood samples from women who appeared to be healthy and without a family history of any other cancer, as a control group. Genotyping of the XRCC3 Thr241Met gene was studied by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The single nucleotide polymorphism (SNP) genotypes were determined in all participants.

Results:
The findings of this study demonstrated that the Met/Met allele occurred more frequently in patients than controls (OR = 3.3, 95% CI: 1.8–6.04; p = 0.0001), particularly in patients with positive lymph node metastases, grade II and III, and stages III/IV.

Conclusions:
These findings established the association of the Thr241Met genotype with breast cancer among Iraqi women; specifically, the homozygous (Met/Met) genotype appeared to be correlated with risk of breast cancer and cancer prognosis. This genotype was notably more prevalent among women diagnosed with high-grade tumours, as well as advanced stage and metastatic breast cancer.