According to an analysis of prospectively collected data for a large cohort of patients with stage I to III esophageal cancer treated with chemoradiotherapy with or without surgery, 15% of patients experienced a grade 3 or higher cardiac adverse event (AE) within 2 years following the administration of chemoradiotherapy. These findings were reported in the Journal of Thoracic Oncology.
Multimodality therapy, including chemoradiotherapy, is the standard-of-care for the treatment of patients with locoregional esophageal cancer. While late cardiotoxicity has been well documented in patients with breast cancer and Hodgkin lymphoma treated with chest irradiation, the higher radiation therapy (RT) doses typically administered in the setting of esophageal cancer raise the possibility of earlier onset cardiac toxicity. Nevertheless, the effect of RT on the cumulative incidence of cardiac AEs and overall survival (OS) for patients with locoregional esophageal cancer has not been well investigated.
This observational study included 479 patients with stage I to III esophageal cancer who underwent preoperative or definitive RT with either intensity modulated RT (IMRT) or proton beam therapy (PBT) at the MD Anderson Cancer Center in Houston, Texas, between March 2005 and August 2017. Data related to cardiac toxicity were retrospectively abstracted from patient medical records.
Patient characteristics included a median age of 62 years, with clinical stage III disease diagnosed in 66.2% of patients, and surgery performed in 59.3% of patients. Approximately two-thirds and one-third of the study population received IMRT and PBT, respectively, and preexisting heart disease was reported in 22.8% of patients.
At a median follow-up of 76 months, the 2-year and 5-year cumulative incidences of grade 3 or higher cardiac AEs after accounting for death unrelated to a cardiac AE, were 15% and 18%, respectively, with a median onset of 7 months following RT. The most common grade 3 or higher cardiac AEs were arrhythmia (n=56) followed by heart failure (n=20) and an acute cardiac event (n=16).
Multivariable analyses for time to earliest grade 3 or higher cardiac AE showed preexisting heart disease (hazard ratio [HR], 2.118; 95% CI, 1.346-3.331; P =.001) and the use of IMRT compared with PBT (HR, 1.746; 95% CI, 1.065-2.862; P =.027) were correlated with the occurrence of a grade 3 or higher cardiac AE. Furthermore, higher mean heart dose (MHD) of RT was also significantly associated with a grade 3 or higher cardiac event (HR, 1.034; 95% CI, 1.006-1.062; P =.015).