Trends in heart disease mortality among breast cancer survivors in the US, 1975-2017

Jacqueline B Vo; Cody Ramin; Ana Barac; Amy Berrington de Gonzalez; Lene Veiga

doi:10.1007/s10549-022-06515-5

Trends in heart disease mortality among breast cancer survivors in the US, 1975-2017

Breast Cancer Res Treat. 2022 Apr;192(3):611-622. doi: 10.1007/s10549-022-06515-5. Epub 2022 Feb 2.

Authors

Jacqueline B Vo^{1

2}, Cody Ramin³, Ana Barac⁴, Amy Berrington de Gonzalez³, Lene Veiga³

Affiliations

¹ Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA. jacqueline.vo@nih.gov.
² Cancer Prevention Fellowship Program, Division of Cancer Prevention, Bethesda, MD, USA. jacqueline.vo@nih.gov.
³ Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, USA.
⁴ Director of Cardio-Oncology and Professor of Medicine, Medstar Heart and Vascular Institute, Georgetown University, Washington, DC, USA.

Abstract

Purpose: Heart disease is a significant concern among breast cancer survivors, in part due to cardiotoxic treatments including chemotherapy and radiotherapy. Long-term trends in heart disease mortality have not been well characterized. We examined heart disease mortality trends among US breast cancer survivors by treatment type.

Methods: We included first primary invasive breast cancer survivors diagnosed between 1975 and 2016 (aged 18-84; survived 12 + months; received initial chemotherapy, radiotherapy, or surgery) in the SEER-9 Database. Standardized mortality ratios (SMRs) and 10-year cumulative heart disease mortality estimates accounting for competing events were calculated by calendar year of diagnosis and initial treatment regimen. P_trends were assessed using Poisson regression. All statistical tests were 2-sided.

Results: Of 516,916 breast cancer survivors, 40,812 died of heart disease through 2017. Heart disease SMRs declined overall from 1975-1979 to 2010-2016 (SMR 1.01 [95%CI: 0.98, 1.03] to 0.74 [0.69, 0.79], p_trend < 0.001). This decline was also observed for survivors treated with radiotherapy alone and chemotherapy plus radiotherapy. A sharper decline in heart disease SMRs was observed from 1975 to 1989 for left-sided radiotherapy, compared to right-sided. In contrast, there was a non-significant increasing trend in SMRs for chemotherapy alone, and significant by regional stage (p_trend = 0.036). Largest declines in 10-year cumulative mortality were observed from 1975-1984 to 2005-2016 among surgery only: 7.02% (95%CI: 6.80%, 7.23%) to 4.68% (95%CI: 4.39%, 4.99%) and radiotherapy alone: 6.35% (95%CI: 5.95%, 6.77%) to 2.94% (95%CI: 2.73%, 3.16%).

Conclusions: We observed declining heart disease mortality trends by most treatment types yet increasing for regional stage patients treated with chemotherapy alone, highlighting a need for additional studies with detailed treatment data and cardiovascular management throughout cancer survivorship.

Keywords: Breast cancer; Cancer survivorship; Descriptive epidemiology; Heart disease mortality.

MeSH terms

Adolescent
Adult
Aged
Aged, 80 and over
Breast Neoplasms*
Cancer Survivors*
Female
Heart
Heart Diseases* / epidemiology
Heart Diseases* / etiology
Humans
Middle Aged
Survivors
Young Adult