@article{MerzenichBaakenSchmidtetal.2022,
  author    = {Merzenich, Hiltrud and Baaken, Dan and Schmidt, Marcus and Bekes, Inga and Schwentner, Lukas and Janni, Wolfgang and Woeckel, Achim and Bartkowiak, Detlef and Wiegel, Thomas and Blettner, Maria and Wollschl{\"a}ger, Daniel and Schmidberger, Heinz},
  title     = {Cardiac late effects after modern 3D-conformal radiotherapy in breast cancer patients: a retrospective cohort study in Germany (ESCaRa)},
  series = {Breast Cancer Research and Treatment},
  volume    = {191},
  journal   = {Breast Cancer Research and Treatment},
  number    = {1},
  issn      = {0167-6806},
  doi       = {10.1007/s10549-021-06412-3},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-308606},
  pages     = {147-157},
  year      = {2022},
  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.},
  language  = {en}
}