Incidence and Onset of Severe Cardiac Events After Radiotherapy for Esophageal Cancer

Abstract Purpose Late cardiotoxicity related to radiotherapy (RT) in breast cancer and Hodgkin lymphoma has been well reported. However, the relatively higher cardiac dose exposure for esophageal cancer (EC) may result in earlier onset of cardiac diseases. In this report, we examined the incidence, onset, and long-term survival outcomes of high-grade cardiac events after RT in a large cohort of EC patients. Patients and Methods Between March 2005 and August 2017, 479 patients with EC from a prospectively maintained institutional database at The University of Texas MD Anderson Cancer Center were analyzed. All patients were treated with either intensity modulated RT (IMRT) or proton beam therapy (PBT), either pre-operatively or definitively. We focused on any grade 3 or higher (G3+) cardiac events according to the Common Terminology Criteria for Adverse Events (CTCAE), version 5.0. Results G3+ cardiac events occurred in 18% of patients at a median of 7 months with a median follow-up time of 76 months. Pre-existing cardiac disease (P=0.001) and radiation modality (IMRT vs PBT) (P=0.027) were significantly associated with G3+ cardiac events. Under multivariable analysis, mean heart dose, particularly Conclusion Severe cardiac events were relatively common with early onset in EC patients after radiotherapy, especially those with pre-existing cardiac disease and higher radiation doses to the heart. Optimal treatment approaches should be taken to reduce cumulative doses to the heart, especially for patients with pre-existing cardiac disease.