[Diagnostic value of BRCA1 and p16 gene methylation in sporadic breast cancer].

BACKGROUND AND OBJECTIVE

Aberrant DNA methylation has the potential of being a tumor marker. This study was to evaluate the methylation statuses of BRCA1 and p16 gene promoter in tumor tissue and serum of breast cancer patients, and explore their diagnostic value.

METHODS

The methylation statuses of BRCA1 and p16 genes in 63 specimens of sporadic breast cancer and corresponding serum samples were detected by methylation-specific polymerase chain reaction (MSP). The serum level of CA15-3 was detected by immunofluorescent method.

RESULTS

The methylation rates of BRCA1 and p16 were 34.9% and 28.6% in tumor tissues, and were 31.7% and 25.4% in corresponding serum samples; the methylation rate of BRCA1 and/or p16 was 60.3% in tumor tissues, and was 54.0% in serum samples. The methylation rate of BRCA1 and/or p16 was related with tumor histological type, lymph node metastases and living area of patients (P<0.05). The sensitivity and specificity of CA15-3 as a diagnostic index for breast cancer were 47.6% and 93.1%; while the sensitivity and specificity of gene methylation and CA15-3 detection in combination were 84.1% and 93.1%. Univariate analysis showed that the methylation of BRCA1 and/or p16, tumor type and living area of patients were related to tumor recurrence with relative risk of 14.0, 6.7 and 5.14 (P<0.05). Multivariate analysis showed that only the methylation of BRCA1 and/or p16 and tumor type were related to tumor recurrence with relative risk of 6.7 and 5.1 (P<0.05).

CONCLUSION

Detecting the methylation of BRCA1 and p16 gene together with CA15-3 is helpful for specific diagnosis of breast cancer, and has a predictive value for tumor recurrence.