Abstract
BACKGROUND: MiR-34b/c takes an important role in various aspects of carcinogenesis. Notably, pri miR34b/c (rs4938723) T>C polymorphism has been identified as a significant biomarker in various kinds of cancer. The objective of this study was to explore whether pri-miR34b/c rs4938723) T>C was associated with breast cancer susceptibility. Moreover, the association of pri-miR34b/c (rs4938723) T>C and clinicopathologic data, including survival outcomes, were studied in Thai breast cancer patients. METHODS: DNA extracted from the blood of 100 Thai female breast cancer patients and 100 Thai healthy women were investigated for pri-miR34b/c (rs4938723) T>C polymorphism using polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP). RESULTS: There was no statistically significant difference between the frequency of pri miR34b/c (rs4938723) T>C genotype between Thai breast cancer patients and normal subjects. This study showed that there is no association between pri-miR34b/c (rs4938723) genotypes and breast cancer susceptibility, clinicopathologic parameters, and survival time. However, age greater than 50 and histologic grade III were the prognostic factors affecting survival in breast cancer patients (p=0.017, p=0.010, respectively). CONCLUSION: The pri-miR34b/c (rs4938723) genotypes had no association with cancer susceptibility and clinicopathologic parameters in Thai breast cancer patients. Patients with older age and patients with higher histologic grade, but not the pri miR34b/c (rs4938723) genotype, affected survival time among breast cancer patients.