Lipid levels do not mediate link between breast density, cancer

  • Lucht SA & al.
  • Cancer Causes Control
  • 1 Jul 2019

  • curated by Miriam Davis, PhD
  • Univadis Clinical Summaries
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Takeaway

  • Analysis of data from the Nurses' Health Study (NHS and NHSII) finds no association between lipid levels and mammographic density, and no effect of lipid levels on the association between high mammographic density and breast cancer.

Why this matters

  • Study does not support the widely held view that high lipid levels, through their role in steroid hormone biosynthesis, may explain the association between high mammographic density and breast cancer.

Study design

  • 2 analyses of NHS and NHSII data:
    • Cross-sectional analysis evaluated total cholesterol (n=1502), high-density lipoprotein (HDL-C; n=579), and triglycerides (n=655) in relation to percent mammographic density (PMD) in healthy women.
    • A nested case-control analysis (cancer cases/matched controls): 937/975 for cholesterol, 416/449 for HDL-C, and 506/537 for triglycerides in relation to PMD.
  • Funding: NIH; others.

Key results

  • The cross-sectional analysis found no associations between any of the 3 types of circulating lipids and average PMD in healthy women, regardless of menopausal status.
  • The case-control study confirmed that high vs low PMD is associated with higher breast cancer risk (OR, 2.27; 95% CI, 1.75-2.94) in postmenopausal women.
    • This association was not influenced by total cholesterol (Pfor interaction=.83), HDL-C (Pfor interaction=.80), or triglycerides (Pfor interaction=.34).

Limitations

  • No data on other lipid biomarkers.