Laterality of Radiation Therapy in Breast Cancer is Not Associated With Increased Risk of Coronary Artery Disease in the Contemporary Era

Lakshya Seth; Omar Makram; Amr Essa; Vraj Patel; Stephanie Jiang; Aditya Bhave; Sandeep Yerraguntla; Gaurav Gopu; Sarah Malik; Justin Swaby; Johnathon Rast; Caleb A Padgett; Ahmed Shetewi; Priyanshu Nain; Neal Weintraub; Eric D Miller; Susan Dent; Ana Barac; Rakesh Shiradkar; Anant Madabhushi; Catherine Ferguson; Avirup Guha

doi:10.1016/j.adro.2024.101583

Laterality of Radiation Therapy in Breast Cancer is Not Associated With Increased Risk of Coronary Artery Disease in the Contemporary Era

Adv Radiat Oncol. 2024 Jul 30;9(10):101583. doi: 10.1016/j.adro.2024.101583. eCollection 2024 Oct.

Authors

Lakshya Seth¹, Omar Makram¹, Amr Essa¹, Vraj Patel¹, Stephanie Jiang¹, Aditya Bhave¹, Sandeep Yerraguntla¹, Gaurav Gopu¹, Sarah Malik¹, Justin Swaby¹, Johnathon Rast¹, Caleb A Padgett¹, Ahmed Shetewi¹, Priyanshu Nain¹, Neal Weintraub¹, Eric D Miller², Susan Dent³, Ana Barac⁴, Rakesh Shiradkar⁵, Anant Madabhushi⁵, Catherine Ferguson⁶, Avirup Guha⁷

Affiliations

¹ Department of Medicine, Medical College of Georgia, Augusta, Georgia.
² Department of Radiation Oncology at the Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio.
³ Duke Cancer Institute, Duke University, Durham, North Carolina.
⁴ Division of Cardio-Oncology, Inova Schar Cancer Institute and Inova Heart and Vascular Institute, Fairfax, Virginia.
⁵ Wallace H Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, Georgia.
⁶ Department of Radiation Oncology, Medical College of Georgia, Augusta University, Augusta, Georgia.
⁷ Cardio-Oncology Program, Medical College of Georgia, Augusta, Georgia.

Abstract

Purpose: External beam radiation therapy (EBRT) is a critical component of breast cancer (BC) therapy. Given the improvement in technology in the contemporary era, we hypothesized that there is no difference in the development of or worsening of existing coronary artery disease (CAD) in patients with BC receiving left versus right-sided radiation.

Methods and materials: For the meta-analysis portion of our study, we searched PubMed, Web of Science, and Scopus and included studies from January 1999 to September 2022. CAD was identified using a homogenous metric across multiple studies included. We computed the risk ratio (RR) for included studies using a random effects model. For the institutional cohort portion of our study, we selected high cardiovascular-risk patients who received diagnoses of BC between 2010 and 2022 if they met our inclusion criteria. We performed a Cox proportional hazards model with stepwise adjustment.

Results: A pooled random effects model with 9 studies showed that patients with left-sided BC receiving EBRT had a 10% increased risk of CAD when compared with patients with right-sided BC receiving EBRT (RR, 1.10; 95% CI, 1.02-1.18; P = .01). However, subgroup analysis of 6 studies that included patients diagnosed after 1980 did not show a significant difference in CAD based on BC laterality (RR, 1.07; 95% CI, 0.95-1.20; P = .27). For the institutional cohort portion of the study, we found that patients with left-sided BC who received EBRT did not have a significantly higher risk of CAD when compared with their right-sided counterparts (hazard ratios [HR], 0.73; 95% CI, 0.34-1.54; P = .402).

Conclusions: Our study suggests a historical trend of increased CAD in BC patients receiving left-sided EBRT. Data from patients diagnosed after 2010 in our institutional cohort did not show a significant difference, emphasizing that modern EBRT regimens are safe, and laterality of BC does not affect CAD outcomes in the short term after a BC diagnosis.