title: Radiotherapy-induced global and regional differences in early-stage left-sided versus right-sided breast cancer patients: speckle tracking echocardiography study.
abstract: Radiotherapy (RT) to the thoracic region increases late cardiovascular morbidity and mortality. The impact of breast cancer laterality on cardiac function is largely unknown. The aim of this prospective study was to compare RT-induced changes in left-sided and right-sided breast cancer patients using speckle tracking echocardiography (STE). Sixty eligible patients with left-sided breast cancer and 20 with right-sided breast cancer without chemotherapy were evaluated prospectively before and early after RT. A comprehensive echocardiographic examination included three dimensional measurements and STE of the left ventricle (LV). The global longitudinal strain (GLS) was reduced from -18.3 ± 3.1 to -17.2 ± 3.3% (p = 0.003) after RT in patients with left-sided breast cancer. Similarly, regional analysis showed a reduction in the apical strain from -18.7 ± 5.3 to -16.7 ± 4.9% (p = 0.002) and an increase in basal values from -21.6 ± 5.0 to -23.3 ± 4.9% (p = 0.024). Patients with right-sided breast cancer showed deterioration in basal anterior strain segments from -26.3 ± 7.6 to -18.8 ± 8.9% (p < 0.001) and in pulsed tissue Doppler by 0.825 [0.365, 1.710] cm/s (p < 0.001). In multivariable analysis, the use of aromatase inhibitor (β = -2.002, p = 0.001) and decreased LV diastolic volume (β = -0.070, p = 0.025) were independently associated with the decrease in GLS. RT caused no changes in conventional LV systolic measurements. RT induced regional changes corresponded to the RT fields. Patients with left-sided breast cancer experienced apical impact and global decline, whereas patients with right-sided breast cancer showed basal changes. The regional differences in cardiac impact warrant different methods in screening and in the follow-up of patients with left-sided versus right-sided breast cancer.
authors.affiliation: Heart Center Co., Heart Hospital, Tampere University Hospital and School of Medicine, University of Tampere, PO Box 2000, 33521, Tampere, Finland. suvi.tuohinen@fimnet.fi.
authors.forename: Suvi Sirkku
authors.initials: SS
authors.lastname: Tuohinen
authors.affiliation: Department of Oncology, Tampere University Hospital and School of Medicine, University of Tampere, Tampere, Finland.
authors.forename: Tanja
authors.initials: T
authors.lastname: Skyttä
authors.affiliation: Department of Pediatrics, Tampere University Hospital and School of Medicine, University of Tampere, Tampere, Finland.
authors.forename: Tuija
authors.initials: T
authors.lastname: Poutanen
authors.affiliation: School of Health Sciences, University of Tampere, Tampere, Finland.
authors.forename: Heini
authors.initials: H
authors.lastname: Huhtala
authors.affiliation: Heart Center Co., Heart Hospital, Tampere University Hospital and School of Medicine, University of Tampere, PO Box 2000, 33521, Tampere, Finland.
authors.forename: Vesa
authors.initials: V
authors.lastname: Virtanen
authors.affiliation: Department of Oncology, Tampere University Hospital and School of Medicine, University of Tampere, Tampere, Finland.
authors.forename: Pirkko-Liisa
authors.initials: PL
authors.lastname: Kellokumpu-Lehtinen
authors.affiliation: Heart and Lung Center, Helsinki University Hospital, Helsinki, Finland.
authors.forename: Pekka
authors.initials: P
authors.lastname: Raatikainen
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D016009:Chi-Square Distribution; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008875:Middle Aged; D015999:Multivariate Analysis; D009200:Myocardial Contraction / Q000528:radiation effects*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011832:Radiation Injuries / Q000000981:diagnostic imaging* / Q000209:etiology / Q000503:physiopathology; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D020266:Radiotherapy, Conformal / Q000009:adverse effects*; D015203:Reproducibility of Results; D012307:Risk Factors; D013318:Stroke Volume / Q000528:radiation effects*; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left / Q000528:radiation effects
keywords: Breast cancer; Laterality; Radiotherapy; Speckle tracking