TY  - JOUR
A1  - Merzenich, Hiltrud
A1  - Baaken, Dan
A1  - Schmidt, Marcus
A1  - Bekes, Inga
A1  - Schwentner, Lukas
A1  - Janni, Wolfgang
A1  - Woeckel, Achim
A1  - Bartkowiak, Detlef
A1  - Wiegel, Thomas
A1  - Blettner, Maria
A1  - Wollschläger, Daniel
A1  - Schmidberger, Heinz
T1  - Cardiac late effects after modern 3D-conformal radiotherapy in breast cancer patients: a retrospective cohort study in Germany (ESCaRa)
T2  - Breast Cancer Research and Treatment
N2  - 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.
KW  - breast cancer
KW  - 3D-conformal radiotherapy
KW  - cardiac mortality
KW  - cardiac morbidity
KW  - cohort study
KW  - survival
Y1  - 2022
UR  - https://opus.bibliothek.uni-wuerzburg.de/frontdoor/index/index/docId/30860
UR  - https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-308606
SN  - 0167-6806
SN  - 1573-7217
VL  - 191
IS  - 1
ER  -