The relationship of single-strand breaks in DNA to breast cancer risk and to tissue concentrations of oestrogens

Abstract

Context: Clinical study of breast cancer patients in Chicago, IL, USA.

Objective: Ascertain the utility of measurements of single-strand breaks (SSB) in DNA for assessment of breast cancer risk.

Methods: Fine-needle aspirates of the breast, SSB by nick translation, percent breast density (PBD), Gail model risk, cumulative methylation index (CMI), enzymes of DNA repair and tissue antioxidants.

Results: DNA repair enzymes and 4-hydroxyestradiol were negatively associated with SSB; CMI and PBD were positively associated.

Conclusions: Quantitative measurement of SSBs by this procedure indicates the relative number of SSBs and is related to promoter methylation, antioxidant availability and percent breast density.

Keywords:

• Breast cancer
• single-strand breaks in DNA
• breast cancer risk
• tissue oestrogens
• DNA methylation

Acknowledgements

This study was supported by grants from the Avon Foundation Prevention Initiative, “Gene methylation and œstradiol levels in random FNA samples as biomarkers of breast cancer risk, 02-2011-108” to Drs Vered Stearns, Seema A. Khan and Saraswati Sukumar. We appreciate the assistance of Peng Huang, PhD, Associate Professor of Onology, Johns Hopkins School of Medicine, Baltimore, MD, in the statistical analyses and Carola Zalles, MD, Mercy Hospital, Miami, FL, for cytopathological analyses.

Disclosure statement

All authors state that they have no conflicts of interest.

Additional information

Funding

This study was supported by grants from the Avon Foundation (Prevention Initiative), “Gene methylation and œstradiol levels in random FNA samples as biomarkers of breast cancer risk, 02-2011-108” to Drs Vered Stearns, Seema A. Khan and Saraswati Sukumar.