Increased EAT volume after anthracycline chemotherapy is associated with a low risk of cardiotoxicity in breast cancer.

Purpose: Chemotherapy-induced cardiotoxicity is a critical issue for patients with breast cancer. Change of epicardial adipose tissue (EAT) is associated with cardiac dysfunction. The objective of this study was to investigate the relationship between EAT and chemotherapy-induced cardiotoxicity.

Methods: This retrospective study analyzed EAT on chest computed tomography (CT) of patients with early breast cancer using automatic, quantitative measurement software between November 2015 and January 2020. Changes in EAT before and after initiation of chemotherapy were compared according to the type of anticancer drug. Subclinical cardiotoxicity was defined as worsening ≥ 10% in left ventricular ejection fraction to an absolute value > 50% with a lower limit of normal measured with standard echocardiography.

Results: Among 234 patients with breast cancer, 85 were treated with adjuvant anthracycline-based (AC) and 149 were treated with non-anthracycline-based (non-AC) chemotherapy. There was a significant increase in EAT volume index (mL/kg/m) at the end of chemotherapy compared to that at the baseline in the AC group (3.33 ± 1.53 vs. 2.90 ± 1.52, p < 0.001), but not in the non-AC group. During the follow-up period, subclinical cardiotoxicity developed in 20/234 (8.6%) patients in the total population [13/85 (15.3%) in the AC group and 7/149 (4.8%) in the non-AC group]. In the multivariable analysis, EAT volume index increment after chemotherapy was associated with a lower risk of subclinical cardiotoxicity in the AC group (Odds ratio: 0.364, 95% CI 0.136-0.971, p = 0.044).

Conclusions: Measurement of EAT during anthracycline-based chemotherapy might help identify subgroups who are vulnerable to chemotherapy-induced cardiotoxicity. Early detection of EAT volume change could enable tailored chemotherapy with cardiotoxicity prevention strategies.