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Menopausal hormone therapy use and long-term all-cause and cause-specific mortality in the Long Island Breast Cancer Study Project |
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| Authors: | Tengteng Wang Patrick T. Bradshaw Patricia G. Moorman Sarah J. Nyante Hazel B. Nichols Sumitra Shantakumar Humberto Parada Jr Nikhil K. Khankari Mary Beth Terry Susan L. Teitelbaum Alfred I. Neugut Marilie D. Gammon |
| Affiliation: | 1. Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA;2. Division of Epidemiology and Biostatistics, University of California, Berkeley, California, USA;3. Department of Community and Family Medicine, Duke University, Durham, North Carolina, USA;4. Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina, USA Department of Radiology, University of North Carolina, Chapel Hill, North Carolina, USA;5. Real World Evidence and Epidemiology Department, GlaxoSmithKline, Singapore, Singapore;6. Division of Epidemiology and Biostatistics, San Diego State University, San Diego, California, USA;7. Division of Epidemiology, Vanderbilt University Medical Center, Nashville, Tennessee, USA;8. Department of Epidemiology, Columbia University, New York, New York, USA;9. Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, New York, USA;10. Department of Epidemiology, Columbia University, New York, New York, USA Department of Medicine, Columbia University, New York, New York, USA |
| Abstract: | Previous studies have observed a reduced mortality risk associated with menopausal hormone therapy (MHT) use among breast cancer survivors. We sought to clarify whether such association could be explained by tumor heterogeneity, specific causes of death, confounding from comorbidities or health behaviors, and a comparison group of women without breast cancer. We interviewed 1508 women newly diagnosed with first primary breast cancer in 1996 to 1997 (~3 months after diagnosis), and 1556 age-matched women without breast cancer, about MHT use history. The National Death Index was used to ascertain vital status after a median of 17.6 years of follow-up (N = 597 deaths for breast cancer subjects). Multivariable-adjusted Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (95%CIs) for all-cause mortality, and cause-specific HR (cHR) for breast cancer and cardiovascular disease (CVD). The Fine-Gray model was used to account for competing causes of death. Among women with breast cancer, ever vs never MHT use was inversely associated with all-cause (HR = 0.77, 95%CI = 0.62-0.95), breast cancer-specific (cHR = 0.69, 95%CI = 0.48-0.98), and CVD-specific mortality (cHR = 0.57, 95%CI = 0.38-0.85). Difference of the association was observed in breast cancer-specific mortality according to hormone receptor status (negative tumors: cHR = 0.44, 95%CI = 0.19-1.01; positive tumors: cHR = 0.96, 95%CI = 0.60-1.53). Among the comparison group, we observed similar, but more modest inverse associations for all-cause and CVD-specific mortality. MHT use was inversely associated with mortality after breast cancer, even after accounting for competing causes of death and multiple confounders, and was evident among women without breast cancer. Potential heterogeneity by hormone receptor status requires more study. |
| Keywords: | breast cancer menopausal hormone therapy mortality survivorship |