Association between body mass index and cardiac dysfunction during human epidermal growth factor receptor 2 inhibitor therapy for breast cancer
M Miharu, M Wakasa, S Yasuyuki, T TaketsyguAbstract
Purpose
In recent years, the administration of human epidermal growth factor receptor 2 inhibitors (HER2i) has improved the survival rate of patients with breast cancer. However, there have been several reports of cancer therapy-related cardiac dysfunction (CTRCD) as an adverse effect. This study aimed to evaluate the incidence of CTRCD associated with HER2i treatment and to explore the risk factors for this condition.
Methods
This retrospective study included 94 female patients diagnosed with breast cancer at our Medical University Hospital from January 1, 2017, to August 31, 2023. A retrospective chart review was conducted to obtain patients’ clinical characteristics as well as blood and echocardiographic data. The median pretreatment body mass index (BMI); 22.3 kg/m2 divided patients into low BMI and high BMI groups. The patients were evaluated for the changes in red cell distribution width (RDW), left ventricular ejection fraction (LVEF), and global longitudinal strain (GLS).
Results
A total of 32 subjects exhibited a decrease in LVEF 6 months after the treatment initiation compared with the pretreatment period. Of the patients, two had LVEF <50% and a decline in LVEF of 10% or more. The rate of LVEF decline was significantly greater in the low than in the high BMI group (−5.1% vs. −0.4%, p = 0.023). The association between BMI and the rate of LVEF decline was stronger in the combined epirubicin group (r = 0.480, p = 0.024) than in the non-epirubicin group (r = 0.230, p = 0.205). The percent change in RDW and GLS was not associated with BMI or LVEF.
Conclusion
In patients with breast cancer treated with HER2i, low BMI was associated with an increased risk of cardiotoxicity. During HER2i treatment, careful monitoring of cardiac function is recommended, particularly for patients with low BMI.