gms | German Medical Science

MAINZ//2011: 56. GMDS-Jahrestagung und 6. DGEpi-Jahrestagung

Deutsche Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie e. V.
Deutsche Gesellschaft für Epidemiologie e. V.

26. - 29.09.2011 in Mainz

Impact of menopausal hormone therapy, breast tumor characteristics, and treatment on overall survival of 3813 breast cancer patients (The Marieplus study)

Meeting Abstract

  • Nadia Obi - UCCH, Universitätsklinikum Hamburg Eppendorf, Hamburg
  • Judit Heinz - UCCH, Universitätsklinikum Hamburg Eppendorf, Hamburg
  • Alina Vrieling - Deutsches Krebsforschungszentrum, Heidelberg
  • Jenny Chang-Claude - Deutsches Krebsforschungszentrum, Heidelberg
  • Dieter Flesch-Janys - UCCH, Universitätsklinikum Hamburg Eppendorf, Hamburg

Mainz//2011. 56. Jahrestagung der Deutschen Gesellschaft für Medizinische Informatik, Biometrie und Epidemiologie (gmds), 6. Jahrestagung der Deutschen Gesellschaft für Epidemiologie (DGEpi). Mainz, 26.-29.09.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. Doc11gmds217

DOI: 10.3205/11gmds217, URN: urn:nbn:de:0183-11gmds2176

Published: September 20, 2011

© 2011 Obi et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


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.
2.
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.
3.
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.
4.
Beral V, et al. Breast cancer and hormone-replacement therapy in the Million Women Study. Lancet. 2003;362(9382):419-427.