Association of ESR1, HER1, and HER2 Polymorphisms with Breast Cancer Risk in the KP Population, A Case-Control Study

Breast cancer is a complex disease characterized by the uncontrolled growth of breast cells. Genetic variants in ESR1, HER1, and HER2 have been associated with breast cancer risk across different populations, with varying results. This study aimed to validate the association of ESR1 (rs2234693 and rs2046210), HER1 (rs11543848), and HER2 (rs1136201) variants with breast cancer risk in the KP population of Pakistan using a larger dataset. The study cohort included 528 patients with BC and 530 healthy controls. Blood samples were collected, and DNA was extracted using a non-enzymatic method. Genotyping was performed using the T-ARMS-PCR protocol. Our results for ESR1 (rs2234693) indicated a non-significant association between the mutant C allele (P = 0.102), TC (P = 0.1002), and CC genotype (P = 0.398) and breast cancer risk. In contrast, ESR1 and rs2046210 showed a significant association with the mutant A allele (P = 0.001), GA (P = 0.001), and AA genotype (P = 0.001), indicating an increased risk. HER1 and rs11543848 showed an increased risk of breast cancer, with the mutant allele A (P = 0.001), GA (P = 0.001), and AA genotype (P = 0.001). Similarly, alleles G (P = 0.004), AG (P = 0.001), and GG genotype (P = 0.003) of HER2 (rs1136201) were associated with higher breast cancer risk. Furthermore, ESR1 (rs2234693) was significantly associated with PR status, while both HER1 (rs11543848) and HER2 (rs1136201) were considerably associated with HER2 receptor status. In conclusion, this study explored the association of the selected variants of ESR1, HER1, and HER2 with breast cancer risk in the KP population using a larger data set, providing valuable insights into the genetic factors contributing to breast cancer risk and corresponding value added to breast cancer management.