Objectives: The aim of our study was to evaluate the prognostic significance of RASSF1A promoter methylation status in operable breast cancer.
Design and methods: By using Methylation Specific PCR, we evaluated the specificity of RASSF1A promoter methylation in 10 breast tumors and matching normal tissues, 10 breast fibroadenomas and 11 normal breast tissues. The prognostic significance of RASSF1A methylation was validated in 93 formalin fixed paraffin-embedded (FFPE) tissues obtained from patients with operable breast cancer.
Results: Methylation of RASSF1A promoter was observed in 1/31 (3.2%) non-cancerous breast tissues and 53/93 (57.0%) early stage breast tumors. The only positive sample in the non-cancerous breast tissues group was found in a histological normal tissue surrounding the tumor. During the follow-up period, 24/93 (25.8%) patients relapsed and 19/93 (20.4%) died. Disease-Free-Interval (DFI) was significantly associated with RASSF1A methylation (p=0.028).
Conclusions: RASSF1A promoter methylation provides important prognostic information in early stage breast cancer patients.