Authors:	Merzenich, Hiltrud Baaken, Dan Schmidt, Marcus Bekes, Inga Schwentner, Lukas Janni, Wolfgang Woeckel, Achim Bartkowiak, Detlef Wiegel, Thomas Blettner, Maria Wollschläger, Daniel Schmidberger, Heinz
Title:	Cardiac late effects after modern 3D-conformal radiotherapy in breast cancer patients : a retrospective cohort study in Germany (ESCaRa)
Online publication date:	30-Aug-2022
Year of first publication:	2022
Language:	english
Abstract:	Purpose Radiotherapy (RT) was identified as a risk factor for long-term cardiac effects in breast cancer patients treated until the 1990s. However, modern techniques reduce radiation exposure of the heart, but some exposure remains unavoidable. In a retrospective cohort study, we investigated cardiac mortality and morbidity of breast cancer survivors treated with recent RT in Germany. Methods A total of 11,982 breast cancer patients treated between 1998 and 2008 were included. A mortality follow-up was conducted until 06/2018. In order to assess cardiac morbidity occurring after breast cancer treatment, a questionnaire was sent out in 2014 and 2019. The effect of breast cancer laterality on cardiac mortality and morbidity was investigated as a proxy for radiation exposure. We used Cox Proportional Hazards regression analysis, taking potential confounders into account. Results After a median follow-up time of 11.1 years, there was no significant association of tumor laterality with cardiac mortality in irradiated patients (hazard ratio (HR) for left-sided versus right-sided tumor 1.09; 95% confidence interval (CI) 0.85–1.41). Furthermore, tumor laterality was not identified as a significant risk factor for cardiac morbidity (HR = 1.05; 95%CI 0.88–1.25). Conclusions Even though RT for left-sided breast cancer on average incurs higher radiation dose to the heart than RT for right-sided tumors, we found no evidence that laterality is a strong risk factor for cardiac disease after contemporary RT. However, larger sample sizes, longer follow-up, detailed information on individual risk factors and heart dose are needed to assess clinically manifest late effects of current cancer therapy.
DDC:	610 Medizin 610 Medical sciences
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 04 Medizin
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-7647
Version:	Published version
Publication type:	Zeitschriftenaufsatz
License:	CC BY
Information on rights of use:	https://creativecommons.org/licenses/by/4.0/
Journal:	Breast cancer research and treatment 191
Pages or article number:	147 157
Publisher:	Springer Science + Business Media B.V.
Publisher place:	Dordrecht u.a.
Issue date:	2022
ISSN:	1573-7217
Publisher DOI:	10.1007/s10549-021-06412-3
Appears in collections:	JGU-Publikationen