Sestak, I, Smith, SG orcid.org/0000-0003-1983-4470, Howell, A et al. (2 more authors) (2018) Early participant-reported symptoms as predictors of adherence to anastrozole in the International Breast Cancer Intervention Studies II. Annals of Oncology, 29 (2). pp. 504-509. ISSN 0923-7534
Abstract
Background: Anastrozole reduces breast cancer risk in women at high risk, but implementing preventive therapy in clinical practice is difficult. Here, we evaluate adherence to anastrozole in the International Breast Cancer Intervention Study (IBIS) II prevention and Ductal Carcinoma in Situ (DCIS) trials, and its association with early symptoms. Patients and methods: In the prevention trial, 3864 postmenopausal women were randomized to placebo vs. anastrozole. 2980 postmenopausal women with DCIS were randomized to tamoxifen vs. anastrozole. Adherence to trial medication was calculated using the Kaplan-Meier method and all Pvalues were two-sided. Results: In the prevention trial, adherence was 65.8% (anastrozole (65.7%) vs. placebo (65.9%); HR=0.97 (0.87-1.09), p=0.6). Adherence was lower for those reporting arthralgia in the placebo group (p=0.02) or gynecological symptoms in the anastrozole group (P=0.003), compared with those not reporting these symptoms at 6 months. In the DCIS study, adherence was 66.7% (anastrozole (67.5%) vs. tamoxifen (65.8%); HR=1.06 (0.94-1.20), p=0.4). Hot flashes were associated with greater adherence in the anastrozole arm (p=0.02). In both studies, symptoms were mostly mild or moderately severe, and adherence decreased with increasing severity for most symptoms. Dropouts were highest in the first 1.5 years of therapy in both trials. Conclusions: In the IBIS-II prevention and DCIS trials, over two-thirds of women were adherent to therapy, with no differences by treatment groups. Participants who reported specific symptoms in the IBIS-II prevention trial had a small but significant effect on adherence, which strengthened as severity increased. Strategies to promote adherence should target the first year of preventive therapy.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author 2017. Published by Oxford University Press on behalf of the European Society for Medical Oncology. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
Keywords: | breast cancer, prevention, adherence, endocrine therapy |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Medicine and Health (Leeds) > School of Medicine (Leeds) |
Funding Information: | Funder Grant number Cancer Research UK C42785/A17965 |
Depositing User: | Symplectic Publications |
Date Deposited: | 20 Nov 2017 12:37 |
Last Modified: | 24 Mar 2018 05:16 |
Status: | Published |
Publisher: | Oxford University Press |
Identification Number: | 10.1093/annonc/mdx713 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:124238 |