The development of carcinoma has been found to be associated with epigenetic modifications. The aim of this study was to estimate the methylation levels of FHIT and BRCA1 promoters using the bisulphite sequencing method (BSP) and high-resolution melting curve analysis (HRM) in the serum of patients with ductal breast carcinoma as a biomarker for the possible application of early diagnosis of breast cancer. The results showed that the methylation levels of both BRCA1 and FHIT promoters were higher in the serum of the breast ductal carcinoma group (BDC group) than those of the breast fibroadenoma group (BFA group), and the healthy individuals group (HI group). However, the methylation levels of the BRCA1 promoters were very low in all three groups compared to the levels of FHIT. The advanced quantitative detection of the samples with HRM showed that the FHIT promoter methylation level of the cfDNA in each serum was also very high in the BDC group compared to the HI group. The methylation level of FHIT was found to be significantly associated with breast cancer (p < 0.05). In conclusion, the methylation quantitative detection of FHIT promoter in serum may be useful for the early diagnosis of ductal breast carcinoma.
Keywords: BRCA1; FHIT; breast cancer; cfDNA; methylation.