Progression of coronary artery calcification after radiation therapy for esophageal cancer

Advances in cancer treatment have resulted in increased attention toward potential cardiac complications, especially following treatment for esophageal cancer, which is associated with a risk of coronary artery disease. As the heart is directly irradiated during radiotherapy, coronary artery calcification (CAC) may progress in the short term. Therefore, we aimed to investigate the characteristics of patients with esophageal cancer that predispose them to coronary artery disease, CAC progression on PET-computed tomography and the associated factors, and the impact of CAC progression on clinical outcomes. METHODS: We retrospectively screened 517 consecutive patients who received radiation therapy for esophageal cancer from our institutional cancer treatment database between May 2007 and August 2019. CAC scores were analyzed clinically for 187 patients who remained by exclusion criteria. RESULTS: A significant increase in the Agatston score was observed in all patients (1 year: P = 0.001*, 2 years: P < 0.001*). Specifically for patients receiving middle-lower chest irradiation (1 year: P = 0.001*, 2 years: P < 0.001*) and those with CAC at baseline (1 year: P = 0.001*, 2 years: P < 0.001*), a significant increase in the Agatston score was observed. There was a trend for a difference in all-cause mortality between patients who had irradiation of the middle-lower chest (P = 0.053) and those who did not. CONCLUSION: CAC can progress within 2 years after the initiation of radiotherapy to the middle or lower chest for esophageal cancer, particularly in patients with detectable CAC before radiotherapy initiation.