Impact of Radiation on Cardiovascular Outcomes in Patients with Resectable Esophageal Cancer

Abstract

Purpose: Preoperative radiation therapy improves outcomes for operable esophageal cancer patients, though the proximity of the heart to the esophagus puts patients at risk of radiation-induced cardiovascular disease. This study characterizes the impact of radiation therapy and different radiation techniques on cardiovascular morbidity among a large cohort of esophageal cancer patients. Methods: We identified 1,125 Medicare beneficiaries diagnosed between 2000 and 2011 with esophageal cancer who received surgery alone, or surgery preceded by either preoperative chemotherapy or preoperative chemoradiation. We used Medicare claims to identify severe adverse cardiovascular events in the perioperative and postoperative periods. Multivariable logistic regression and Fine-Gray models were used to determine the effect of pre-surgery treatment on the risk of perioperative and postoperative cardiovascular disease. Results: Preoperative chemotherapy or preoperative chemoradiation did not significantly increase the risk of perioperative cardiovascular complications compared to surgery alone. Patients treated with preoperative chemoradiation had a 36% increased risk of having a postoperative cardiovascular event compared to patients treated with surgery alone (subdistribution hazard ratio [SDHR] 1.36; p=0.035). There was no significant increase in cardiovascular events among patients treated with preoperative chemotherapy (SDHR 1.18; p=0.40). Among patients treated with preoperative chemoradiation, those receiving intensity modulated radiotherapy (IMRT) had a 68% decreased risk of having a cardiovascular event compared to patients receiving conventional radiation (SDHR 0.32; p=0.007). Conclusions: This study demonstrates an increased risk of cardiovascular complications among operative esophageal cancer patients treated with preoperative chemoradiation, though these risks might be reduced with more cardioprotective radiation techniques such as IMRT.