In order to investigate if aberrant promoter methylation of p16, BRCA1 and RASSF1A genes contributes to biological behavior of triple-negative breast cancer (TNBC), marked as the most aggressive phenotype of breast cancer, we compared the hypermethylation pattern between TNBC and ER+PR+Her2- breast cancer.
Unaffected women undergoing mutation testing for BRCA1/2 should be advised that there is limited reassurance from a negative test result if their close relative had a HER2+ breast cancer.