Estrogen-Progestagen Menopausal Hormone Therapy and Breast Cancer: Does Delay From Menopause Onset to Treatment Initiation Influence Risks?
- 1 November 2009
- journal article
- research article
- Published by American Society of Clinical Oncology (ASCO) in Journal of Clinical Oncology
- Vol. 27 (31), 5138-5143
- https://doi.org/10.1200/jco.2008.21.6432
Abstract
To investigate whether the relation between estrogen-progestagen menopausal hormone therapy (EP-MHT) and breast cancer risk varies according to the delay between menopause onset and treatment initiation. Between 1992 and 2005, 1,726 invasive breast cancers were identified among 53,310 postmenopausal women from the French E3N cohort (mean duration of follow-up, 8.1 years). Hazard ratios (HRs) and CIs were estimated using Cox models, with MHT never users as the reference. Among recent users of EP-MHT, the risk of breast cancer varied according to the timing of treatment initiation. This variation was confined to short durations of use (≤ 2 years): the HR was 1.54 (95% CI, 1.28 to 1.86) for short treatments initiated in the 3-year period following menopause onset and 1.00 (95% CI, 0.68 to 1.47) for short treatments initiated later (P = .04 for homogeneity). However, this pattern of risks was not observed in users of EP-MHT containing progesterone, among whom there was no significantly increased risk associated with short duration of use (HR was 0.87 [95% CI, 0.57 to 1.32] for treatments initiated ≤ 3 years after menopause, and HR was 0.90 [95% CI, 0.45 to 1.81] for treatments initiated later). Longer durations of EP-MHT use were generally associated with increases in breast cancer risk, whatever the gap time. Our results suggest that, for some EP-MHT, the timing of treatment initiation transiently modulates the risk of breast cancer and that, when initiated close to menopause, even short durations of use are associated with an increased breast cancer risk. Estrogen + progesterone combinations might be an exception in this regard.Keywords
This publication has 30 references indexed in Scilit:
- Menopausal Hormone Therapy and Breast Cancer Risk in the NIH-AARP Diet and Health Study CohortCancer Epidemiology, Biomarkers & Prevention, 2008
- Progestins in Hormone Replacement Therapies Reactivate Cancer Stem Cells in Women with Preexisting Breast Cancers: A HypothesisJournal of Clinical Endocrinology & Metabolism, 2008
- Conjugated Equine Estrogens and Breast Cancer Risk in the Women's Health Initiative Clinical Trial and Observational StudyAmerican Journal of Epidemiology, 2008
- Estrogen Plus Progestin Therapy and Breast Cancer in Recently Postmenopausal WomenAmerican Journal of Epidemiology, 2008
- Use of Different Postmenopausal Hormone Therapies and Risk of Histology- and Hormone Receptor–Defined Invasive Breast CancerJournal of Clinical Oncology, 2008
- Main morbidities recorded in the women's international study of long duration oestrogen after menopause (WISDOM): a randomised controlled trial of hormone replacement therapy in postmenopausal womenBMJ, 2007
- Unequal risks for breast cancer associated with different hormone replacement therapies: results from the E3N cohort studyBreast Cancer Research and Treatment, 2007
- Increased risk of breast cancer following different regimens of hormone replacement therapy frequently used in EuropeInternational Journal of Cancer, 2004
- Risks and Benefits of Estrogen Plus Progestin in Healthy Postmenopausal Women: Principal Results From the Women's Health Initiative Randomized Controlled TrialJAMA, 2002
- Randomized Trial of Estrogen Plus Progestin for Secondary Prevention of Coronary Heart Disease in Postmenopausal WomenJAMA, 1998