A case–control study of the HER2 Ile655Val polymorphism and risk of breast cancer in Taiwan

Objectives: To investigate the HER2 Ile655Val polymorphism in relation to risk of breast cancer in a case–control study in Taiwan. Design and methods: The HER2 polymorphism at codon 655 was analyzed in 424 patients with breast cancer and 318 controls by using the polymerase chain reaction methodology, followed by the restriction fragment-length polymorphism (PCR-RFLP) analysis. Results: There was a 1.48-fold (95% CI = 1.00–2.24) increase in the risk of patients with breast cancer who are Val carrier (Ile/Val and Val/Val genotypes). Furthermore, for the early onset (less than 45 years old) breast cancers with Val carrier, there was a 2.24-fold (95% CI = 1.17–4.34) increase in the risk of breast cancer. Conclusions: Our results indicate that the Val carrier was associated with increased risks in patients with breast cancer in Taiwan. The association was more apparent in patients who were younger than or equal to 45 years of age.