Mammographic density: A potential monitoring biomarker for adjuvant and preventative breast cancer endocrine therapies

Michael S. Shawky, Hilary Martin, Honor J. Hugo, Thomas Lloyd, Kara L. Britt, Andrew Redfern, Erik E.W. Thompson

Research output: Contribution to journalReview ArticleResearchpeer-review

29 Citations (Scopus)


Increased mammographic density (MD) has been shown beyond doubt to be a marker for increased breast cancer risk, though the underpinning pathobiology is yet to be fully elucidated. Estrogenic activity exerts a strong influence over MD, which consequently has been observed to change predictably in response to tamoxifen anti-estrogen therapy, although results for other selective estrogen receptor modulators and aromatase inhibitors are less consistent. In both primary and secondary prevention settings, tamoxifen-associated MD changes correlate with successful modulation of risk or outcome, particularly among pre-menopausal women; an observation that supports the potential use of MD change as a surrogate marker where short-term MD changes reflect longer-term anti-estrogen efficacy. Here we summarize endocrine therapy-induced MD changes and attendant outcomes and discuss both the need for outcome surrogates in such therapy, as well as make a case for MD as such a monitoring marker. We then discuss the process and steps required to validate and introduce MD into practice as a predictor or surrogate for endocrine therapy efficacy in preventive and adjuvant breast cancer treatment settings.

Original languageEnglish
Pages (from-to)5578-5591
Number of pages14
Issue number3
Publication statusPublished - 2017


  • Breast cancer
  • Endocrine therapy
  • Mammographic density
  • Predictive biomarker
  • Surrogate

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