High frequency of promoter hypermethylation of RASSF1A in tumorous and non-tumourous tissue of breast cancer

Pathology. 2005 Apr;37(2):125-30. doi: 10.1080/00313020500058623.


Aim: To determine the presence of RASSF1A promoter methylation in tumorous and non-tumorous tissues of breast cancer.

Methods: Methylation-specific PCR was used to detect RASSF1A methylation in DNA extracted from tumorous and paired non-tumorous tissues of 40 breast cancer patients. The associations of RASSF1A hypermethylation with clinicopathological characteristics in tumorous and non-tumorous breast tissues were analysed.

Results: RASSF1A promoter hypermethylation was detected in 38 of the 40 breast cancer tissues (95%) and 37 of the paired non-tumorous tissues (92.5%). When compared with the non-tumorous tissues, aberrant methylation was detected to be higher in 24 of the tumorous tissues (60%). The latter was found to be associated with lower histological grade tumours (p=0.048).

Conclusion: RASSF1A promoter hypermethylation occurred at a high frequency in breast cancer tumorous and non-tumorous tissues; the majority of tumours have a higher level of methylation status when compared with non-tumorous tissues. This supports the notion that RASSF1A methylation is an early and premalignant alteration.

MeSH terms

  • Adenocarcinoma / genetics*
  • Adenocarcinoma / metabolism
  • Adenocarcinoma / secondary
  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / metabolism
  • Breast / metabolism
  • Breast / pathology*
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • DNA Methylation*
  • DNA, Neoplasm / genetics
  • Female
  • Humans
  • Lymph Nodes / pathology
  • Menopause
  • Middle Aged
  • Polymerase Chain Reaction
  • Promoter Regions, Genetic
  • Tumor Suppressor Proteins / genetics*
  • Tumor Suppressor Proteins / metabolism


  • Biomarkers, Tumor
  • DNA, Neoplasm
  • RASSF1 protein, human
  • Tumor Suppressor Proteins