title: Long-term cardiovascular mortality after radiotherapy for breast cancer: A systematic review and meta-analysis.
abstract: BACKGROUND
  Radiotherapy (RT) is frequently associated with late cardiovascular (CV) complications. The mean cardiac dose from irradiation of a left-sided breast cancer is much higher than that for a right-sided breast cancer. However, data is limited on the long-term risks of RT on CV mortality.
  
  
  OBJECTIVE
  RT for breast cancer is associated with long term CV mortality and left sided RT carries a greater mortality than right sided RT.
  
  
  METHODS
  We searched PubMed, Cochrane Central, Embase, EBSCO, Web of Science, and CINAHL databases from inception through December 2015. Studies reporting CV mortality with RT for left- vs right-sided breast cancers were included. The principal outcome of interest was CV mortality. We calculated summary risk ratio (RR) and 95% confidence intervals (CI) with the random-effects model.
  
  
  RESULTS
  The analysis included 289 109 patients from 13 observational studies. Women who had received RT for left-sided breast cancer had a higher risk of CV death than those who received RT for a right-sided breast cancer (RR: 1.12, 95% CI: 1.07-1.18, P < 0.001; number needed to harm: 353). Difference in CV mortality between left- vs right-sided breast RT was more apparent after 15 years of follow-up (RR: 1.23, 95% CI: 1.08-1.41, P < 0.001; number needed to harm: 95).
  
  
  CONCLUSIONS
  CV mortality from left-sided RT was significantly higher compared with right-sided RT for breast cancer and was more apparent after ≥15 years of follow-up.
authors.affiliation: Division of Cardiovascular Medicine, University of Utah, Salt Lake City.
authors.forename: Partha
authors.initials: P
authors.lastname: Sardar
authors.affiliation: Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts.
authors.forename: Amartya
authors.initials: A
authors.lastname: Kundu
authors.affiliation: St Luke's-Roosevelt Hospital of the Mount Sinai Health System, New York, New York.
authors.forename: Saurav
authors.initials: S
authors.lastname: Chatterjee
authors.affiliation: Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
authors.forename: Anju
authors.initials: A
authors.lastname: Nohria
authors.affiliation: University of Arkansas for Medical Sciences, Little Rock, Arkansas.
authors.forename: Ramez
authors.initials: R
authors.lastname: Nairooz
authors.affiliation: New York University School of Medicine, New York, New York.
authors.forename: Sripal
authors.initials: S
authors.lastname: Bangalore
authors.affiliation: Texas Tech University Health Sciences Center, El Paso, Texas.
authors.forename: Debabrata
authors.initials: D
authors.lastname: Mukherjee
authors.affiliation: New York Medical College, Valhalla, New York.
authors.forename: Wilbert S
authors.initials: WS
authors.lastname: Aronow
authors.affiliation: John Ochsner Heart and Vascular Institute, Ochsner Clinical School/University of Queensland School of Medicine, New Orleans, Louisiana.
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Lavie
mesh_terms: D001943:Breast Neoplasms / Q000532:radiotherapy*; D002318:Cardiovascular Diseases / Q000209:etiology / Q000401:mortality*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005544:Forecasting; D014943:Global Health; D006801:Humans; D015994:Incidence; D011832:Radiation Injuries / Q000150:complications* / Q000453:epidemiology; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends
keywords: Breast Cancer; Cardiovascular Mortality; Radiotherapy