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

Radiother Oncol. 2015 Mar;114(3):328-34. doi: 10.1016/j.radonc.2015.01.006. Epub 2015 Jan 16.

Abstract

Background/purpose: 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).

Materials and 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.

Keywords: Breast cancer; Calcium-score; Cardiovascular; Radiotherapy; Risk factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology
  • Breast Neoplasms / radiotherapy*
  • Calcium / metabolism*
  • Cohort Studies
  • Coronary Artery Disease / etiology*
  • Coronary Artery Disease / metabolism*
  • Coronary Artery Disease / pathology
  • Coronary Vessels / metabolism
  • Coronary Vessels / pathology
  • Coronary Vessels / radiation effects
  • Female
  • Heart / radiation effects*
  • Humans
  • Longitudinal Studies
  • Middle Aged
  • Radiation Injuries / etiology
  • Radiation Injuries / metabolism*
  • Radiation Injuries / pathology
  • Radiotherapy, Adjuvant
  • Risk Factors
  • Surveys and Questionnaires
  • Survivors

Substances

  • Calcium