A decrease in brown adipose tissue activity is associated with weight gain during chemotherapy in early breast cancer...

Area of Science:

• Oncology
• Metabolism
• Nuclear Medicine

Background:

• Chemotherapy may reduce energy expenditure by impacting thermogenesis.
• Brown adipose tissue (BAT) plays a crucial role in metabolic regulation and energy expenditure.

Purpose of the Study:

• To investigate the effect of chemotherapy on brown adipose tissue (BAT) metabolic activity.
• To explore the relationship between chemotherapy-induced changes in BAT activity and weight variations in breast cancer patients.

Main Methods:

• Ancillary analysis of a multicentre trial involving 109 HER2+ breast cancer patients receiving neoadjuvant chemotherapy.
• ¹⁸F-FDG PET-CT scans were used to measure BAT uptake intensity (SUV_max) in cervical and supraclavicular regions before and after the first chemotherapy course.

Main Results:

• A significant 4.4% decrease in overall ¹⁸F-FDG uptake intensity in BAT was observed after one chemotherapy course.
• Patients who gained weight during chemotherapy showed a significant 13.42% decrease in BAT ¹⁸F-FDG uptake (p=0.042).
• No correlation was found between BAT activity changes and initial BMI, age, or season.

Conclusions:

• This study is the first to demonstrate a negative impact of chemotherapy on brown adipose tissue activity in a large patient cohort.
• Reduced BAT activity may partially explain weight gain experienced by some breast cancer patients during chemotherapy.