title: Coronary calcium score in 12-year breast cancer survivors after adjuvant radiotherapy with low to moderate heart exposure - Relationship to cardiac radiation dose and cardiovascular risk factors.
abstract: OBJECTIVE
  We explored the relation between coronary artery calcium (CAC) and cardiac radiation doses in breast cancer survivors (BCS) treated with radiotherapy (RT). Additionally, we examined the impact of other risk factors and biomarkers of coronary artery disease (CAD).
  
  
  METHODS
  236 BCS (median age 51years [range 30-70], median observation time 12years [9.2-15.7]), treated with 4-field RT of 50GY, were included and examined in 2004 (T1), 2007 (T2) and 2011 (T3) with clinical examination, blood tests and questionnaires. At T3, cardiac computed tomography was performed with quantification of CAC using Agatston score (AS). For 106 patients cardiac dose volume histograms were available.
  
  
  RESULTS
  The cohort-based median of the mean cardiac dose was 2.5 (range 0.5-7.0) Gy. There was no correlation between measures of cardiac dose and AS. AS was correlated with high cholesterol at T1/T2 (p=0.022), high proBNP at T1/T2 (p<0.022) and T3 (p<0.022) and high HbA1c at T3 (p=0.022). In addition, a high AS was significantly associated with hypertension (p=0.022). Age (p<0.001) and cholesterol at T1/T2 (p=0.001) retained significant associations in multivariate analysis.
  
  
  CONCLUSIONS
  Traditional, modifiable risk factors of CAD correlate with CAC and may be important for the long term risk of CAD after RT. With low to moderate cardiac radiation exposure, a contribution of radiation dose to CAC could not be demonstrated.
authors.affiliation: National Advisory Unit on Late Effects After Cancer Treatment, Oslo University Hospital, Department of Clinical Cancer Research, Norway. Electronic address: krtjes@ous-hf.no.
authors.forename: Kristin Holm
authors.initials: KH
authors.lastname: Tjessem
authors.affiliation: Department of Radiology and Nuclear Medicine, Division of Diagnostics and Intervention, Oslo University Hospital, Norway.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Bosse
authors.affiliation: Department of Radiology and Nuclear Medicine, Division of Diagnostics and Intervention, Oslo University Hospital, Norway.
authors.forename: Kristian
authors.initials: K
authors.lastname: Fosså
authors.affiliation: National Advisory Unit on Late Effects After Cancer Treatment, Oslo University Hospital, Department of Clinical Cancer Research, Norway.
authors.forename: Kristin V
authors.initials: KV
authors.lastname: Reinertsen
authors.affiliation: National Advisory Unit on Late Effects After Cancer Treatment, Oslo University Hospital, Department of Clinical Cancer Research, Norway.
authors.forename: Sophie D
authors.initials: SD
authors.lastname: Fosså
authors.affiliation: Department of Oncology, Oslo University Hospital, Oslo and Akershus University College of Applied Sciences, Faculty of Health Sciences, Norway.
authors.forename: Safora
authors.initials: S
authors.lastname: Johansen
authors.affiliation: National Advisory Unit on Late Effects After Cancer Treatment, Oslo University Hospital, Department of Clinical Cancer Research, Norway.
authors.forename: Alexander
authors.initials: A
authors.lastname: Fosså
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D002118:Calcium / Q000378:metabolism*; D015331:Cohort Studies; D003324:Coronary Artery Disease / Q000209:etiology* / Q000378:metabolism* / Q000473:pathology; D003331:Coronary Vessels / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects; D005260:Female; D006321:Heart / Q000528:radiation effects*; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D011832:Radiation Injuries / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D018714:Radiotherapy, Adjuvant; D012307:Risk Factors; D011795:Surveys and Questionnaires; D017741:Survivors
chemical_list: D002118:Calcium
keywords: Breast cancer; Calcium-score; Cardiovascular; Radiotherapy; Risk factors