Article
Impact of menopausal hormone therapy, breast tumor characteristics, and treatment on overall survival of 3813 breast cancer patients (The Marieplus study)
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Authors
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Nadia Obi
- UCCH, Universitätsklinikum Hamburg Eppendorf, Hamburg
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Judit Heinz
- UCCH, Universitätsklinikum Hamburg Eppendorf, Hamburg
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Alina Vrieling
- Deutsches Krebsforschungszentrum, Heidelberg
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Jenny Chang-Claude
- Deutsches Krebsforschungszentrum, Heidelberg
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Dieter Flesch-Janys
- UCCH, Universitätsklinikum Hamburg Eppendorf, Hamburg
| Published: | September 20, 2011 |
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Outline
Text
Introduction: Menopausal hormone therapy (HT) is a well established risk factor for developing breast cancer. However, the impact of pre-diagnostic HT use on overall mortality is controversial. The majority of observational studies found a reduced breast cancer mortality, while in the follow-up of the Women’s Health Initiative (WHI) trial [1] HT was associated with a doubling of hazard ratio (HR). To further elucidate the impact of HT on overall survival we analyzed follow-up information of the population based case cohort of the MARIE study.
Methods: Incident breast cancer cases (N = 3813) recruited in 2002-2005 were followed up to the end of 2009. Vital status and causes of death certificates were ascertained. Cox proportional hazard analysis was performed with self-reported pre-diagnostic HT as exposure adjusting for age, characteristics of the primary tumor, treatment, various lifestyle factors, mode of detection and number of mammograms prior to diagnosis.
Results: After a median follow-up of 6.2 years 507 deaths (13.3%) occurred, of which 70% were due to breast cancer. The prognostic tumor characteristics TNM-status, grading and hormone receptors showed significant associations with overall survival. Compared with never users of HT, current HT users of any type had a significantly lower mortality risk (adjusted HR 0.58, 95% CI 0.45-0.74), but not past HT users (HR 0.83, 95% CI 0.62-1.09). The most pronounced risk reduction was seen for continuously combined estrogen-progestin (HR 0.52, 0.37-0.73), the less for mono-estrogen preparations (HR 0.68, 0.46 -0.99).
Discussion: Our results are in line with several former studies [2], [3] which also found an inverse association of pre-diagnostic HT use and survival after breast cancer, though inconsistent with results reported by the WHI [1] and the Million Women Study [4]. Further analysis will be performed to evaluate more closely the HT user profiles (including HT duration, age at start of HT use) and potentially unobserved confounding (e.g. differential co-morbidity between HT non-users and users) by stratification for age and tumor subgroups.
References
- 1.
- Chlebowski RT, Anderson GL, Gass M, et al. Estrogen plus progestin and breast cancer incidence and mortality in postmenopausal women. JAMA. 2010;304(15):1684-1692.
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- Reding K, Doody D, McTiernan A, et al. Age-related variation in the relationship between menopausal hormone therapy and the risk of dying from breast cancer. Breast Cancer Research and Treatment. 2011;126(3):749-761.
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- Newcomb PA, Egan KM, Trentham-Dietz A, et al. Prediagnostic use of hormone therapy and mortality after breast cancer. Cancer Epidemiol Biomarkers Prev. 2008;17(4):864-871.
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- Beral V, et al. Breast cancer and hormone-replacement therapy in the Million Women Study. Lancet. 2003;362(9382):419-427.
