Introduction: Radiotherapy is an important treatment in early stage breast cancer but it is claimed that radiotherapy causes damage to the cardiac conduction system and increases the risk implantation of CIED (pacemaker or ICD). However, this paradigm is based on smaller series of case reports. Due to the anatomy, radiotherapy will potential mainly affect the conduction system in left sided breast cancer. The aim of this study was to evaluate risk of implantation of a CIED subsequent to radiotherapy for breast cancer by comparing left- versus right sided radiotherapy in a nationwide cohort. Methods: From the database of the Danish Breast Cancer Collaborative Group, we identified women treated with radiotherapy for early-stage breast cancer in Denmark from 1982 to 2005. By record linkage to the Danish Pacemaker and ICD Registry information was retrieved on CIED implants subsequent to radiotherapy. The rate ratios (RR) of CIED implantation were estimated by Poisson regression for left- versus right sided breast cancer with stratification for calendar year of breast cancer diagnosis, age at diagnosis and time since diagnosis (all in five-year groups). 95% confidence intervals (CI) and two-sides significance tests were calculated. Results: Among 18,308 women treated with radiotherapy for early-stage breast cancer, 179 women had a CIED implanted (166 pacemakers, 13 ICD) subsequent to radiotherapy, 90 in 9,315 left sided and 89 in 8,993 right sided breast cancers. Follow-up time was minimum 8 years. The unadjusted RR was 1.02 (0.76-1.36 95% CI, p=0.91) and the RR adjusted for year, age and time since diagnosis was 1.06 (0.79-1.42 95% CI, p=0.71). There was thus no difference in risk of CIED implantation after radioterapy in left- versus right sided breast cancer. Conclusions: Radiotherapy for breast cancer is not associated with increased risk of CIED implantation.
|Issue number||5 SUPPL.|
|Number of pages||1|
|Publication status||Published - 2015|
|Event||36th Annual Scientific Sessions of the Heart Rhythm Society, Heart Rhythm 2015 - Boston, United States|
Duration: 13. May 2015 → 16. May 2015
|Conference||36th Annual Scientific Sessions of the Heart Rhythm Society, Heart Rhythm 2015|
|Period||13/05/2015 → 16/05/2015|