INTRODUCTION: Chemoprevention with anti-estrogens can reduce breast cancer risk among high-risk women. However, uptake is estimated to be lower than 15% among women offered anti-estrogens. Women with atypical hyperplasia (AH), lobular carcinoma in situ (LCIS), and ductal carcinoma in situ (DCIS) are at an increased risk of developing invasive breast cancer and often derive more benefit from anti-estrogens compared to other high-risk populations. We sought to determine which factors are associated with chemoprevention uptake in a population of women with AH, LCIS, and DCIS.
METHODS: We conducted a retrospective cohort study at an urban academic center in New York, NY of women diagnosed with AH/LCIS/DCIS between 2007 and 2015 without a history of invasive breast cancer (n=1719). Demographic and clinical information, including type of anti-estrogen and medical oncology referral, were collected from the electronic health record. Breast disease in each patient was classified according to the most advanced lesion (DCIS>LCIS>AH). A subset of women with AH/LCIS/DCIS scheduled for an initial consultation with a medical oncologist (n=73) completed questionnaires on their breast cancer and chemoprevention knowledge, risk perception, and behavioral intentions. Descriptive statistics were generated and univariate and multivariable log-binomial regression were used to estimate the association between sociodemographic and clinical factors and chemoprevention uptake.
RESULTS: In our sample, mean age was 60 years (SD 12); white/black/Hispanic/Asian/other (%): 45/9/23/6/17; AH/LCIS/DCIS (%): 35/24/41; and 33% were referred to a medical oncologist. A total of 505 (29%) women had initiated an anti-estrogen, including 54% who used tamoxifen, 15% raloxifene, 19% aromatase inhibitors, and 11% who tried multiple anti-estrogens. Older women and Hispanics compared to non-Hispanic whites were more likely to take anti-estrogens. Compared to women with AH, LCIS (RR: 1.43; 95% CI: 1.16-1.76) and DCIS (RR: 1.54; 95% CI: 1.28-1.86) were significantly associated with chemoprevention uptake. Medical oncology referral was the strongest predictor of chemoprevention uptake (RR: 5.79; 95% CI: 4.80-6.98). According to the survey data, many women had heard of anti-estrogens for chemoprevention (75%), but few were knowledgeable about it. The majority of participants were worried about the side effects of chemoprevention (72%) and considered them very serious (57%). Satisfaction was high among those who reported making a decision to take chemoprevention, however, only 50% of survey participants thought the benefits of anti-estrogens were worth the risks.
CONCLUSIONS: At our center, women with AH, LCIS, and DCIS have higher rates of chemoprevention uptake compared to the reported literature. Despite the potential for younger women to see a greater lifelong benefit from chemoprevention, our results indicate this population may be less likely to use anti-estrogens. Misperceptions about personal breast cancer risk and chemoprevention adverse effects may be barriers to uptake. Improving patient-provider communication about breast cancer risk and the risks and benefits of chemoprevention may facilitate informed-decision making about anti-estrogen therapy.
