Oral adjuvant endocrine therapy (OAET) substantially improves the survival of women with hormone receptor–positive (HR+) breast cancer. However, we reported previously that at 3 to 4 years after diagnosis, 18% of affected women are not using OAET primarily because of estrogen deficiency symptoms. The aim of this study was to determine the use of OAET in women with HR+ breast cancer 5 to 6 years from diagnosis.
Analysis was carried out using data from the Bupa Health Foundation’s Health and Wellbeing After Breast Cancer Study, a cohort study of 1,683 women with breast cancer who were recruited in Victoria, Australia between 2004 and 2006. All women completed an enrollment questionnaire within 12 months of diagnosis and an annual follow-up questionnaire (FQ) for 5 years. The fifth FQ was completed 5.7 years from the time of diagnosis. Use of OAET was self-reported in response to a series of questions.
A minimal exposure to OAET of at least 5 years (OAET in all six FQs) was reported by 19.7% of the women (n = 212), and another 46.7% (n = 503) received a minimal exposure of at least 4 years (OAET in five questionnaires). In total, 82.1% (n = 883) of the women would have received at least 3 years of treatment (OAET in at least four questionnaires). Only 7.8% (n = 84) reported never using OAET.
Most women with HR+ breast cancer who survive at least 5 years have persisted with OAET despite the adverse effects of estrogen depletion.
The majority of women with hormone receptor positive breast cancer in Victoria Australia who have survived for nearly 6 years, are being treated according to current guidelines regarding oral adjuvant endocrine therapy, and have persisted with therapy, despite the adverse effects of estrogen depletion.
From the 1Women’s Health Program, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia; and 2Department of Medicine, Central Clinical School, Monash University and Alfred Health, Melbourne, Australia.
Received October 2, 2012; revised and accepted November 5, 2012.
Funding/support: This work was supported by the Bupa Health Foundation (previously the Medical Benefits Fund of Australia Limited Foundation; to S.R.D. and R.J.B.), the National Health and Medical Research Council of Australia (grant 219279 to S.R.D. and R.J.B., and grant 490938 to S.R.D.), Novartis Oncology Australia, the L. E. W. Carty Trust, the Jack and Robert Smorgon Families Foundation, and Connie and Craig Kimberley and Roy Morgan Research (all to S.R.D. and R.J.B.). This research project was also supported by the Victorian Government through a Victorian Cancer Agency Research Fellowship (to R.J.B.).
Financial disclosure/conflicts of interest: S.R.D. has served as consultant to Biosante Pharmaceuticals and Bayer Health. M.S. has served on a Roche Advisory Board. All other authors declare that they have no conflicts of interest.
Address correspondence to: Robin J. Bell, MB, BS, PhD, MPH, FAFPHM, Women’s Health Program, School of Public Health and Preventive Medicine, Monash University, Level 6, 99 Commercial Road, Melbourne 3004, Australia. E-mail: email@example.com