Related Experiment Video
Updated: Feb 20, 2026
Intraductal Delivery to the Rabbit Mammary Gland
Published on: March 9, 2017
Endocrine Therapy Initiation among Older Women with Ductal Carcinoma In Situ
Chelsea Anderson1, Aaron N Winn2, Stacie B Dusetzina2,3,4
1Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Background:
Although treatment of ductal carcinoma in situ (DCIS) is controversial, national guidelines recommend considering endocrine therapy for women with estrogen receptor- (ER-) positive DCIS or those undergoing breast conserving surgery (BCS) without radiation. We evaluated uptake and predictors of endocrine therapy use among older women with DCIS.
Methods:
In the SEER-Medicare database, we identified women aged 65+ years diagnosed with DCIS during 2007-2011. We evaluated demographic, tumor, and treatment characteristics associated with endocrine therapy initiation.
Results:
Among 2,945 women with DCIS, 41% initiated endocrine therapy (66% tamoxifen, 34% aromatase inhibitors). Initiation was more common among women with ER-positive than ER-negative DCIS (48% versus 16%; HR = 3.75, 95% CI: 2.91-4.83); 28% of women with unknown ER status initiated endocrine therapy. Initiation was less common after BCS alone compared to BCS with radiation (32% versus 50%; HR = 0.69, 95% CI: 0.59-0.80).
Conclusions:
Less than half of older women with DCIS initiate endocrine therapy to prevent second breast cancers. Our findings suggest use was more common, but not exclusive, among women with ER-positive DCIS, but not among women who underwent BCS alone. Endocrine therapy should be targeted toward patients most likely to benefit from its use.
