Change in breast density as a response to adjuvant endocrine treatment: An American cohort.

Abstract

e11523 Background: Anti-estrogen treatment is the cornerstone in adjuvant therapy of estrogen receptor (ER) positive breast cancer. Previous work has demonstrated that endocrine therapy (ET) reduces breast density on subsequent mammograms. Research from Korea and Sweden has shown that decreased mammographic density (MD) after ET is a positive prognostic marker for long-term survival. We seek to validate this finding in a North American cohort. Methods: We identified 102 patients treated at our institution with ER positive breast cancer from 2003-2006, with mammograms available in our system and an intact contralateral breast. MD was measured as percentage volume density using Volpara software (v. 1.2); MD reduction (MDR) was defined as Follow up MD - Baseline MD*100 / Baseline MD. Baseline MD was measured from a preoperative mammogram, and Follow up MD from mammograms taken 1-2 years after start of ET. Logistic regression analysis was performed with endpoint defined as locoregional or distant breast cance...