Preliminary investigation of brown adipose tissue assessed by PET/CT and cancer activity

ObjectiveTo determine the role of brown adipose tissue (BAT) in cancer activity.Materials and methodsThe study group comprised 142 patients (121 female, 21male; mean age, 4916years) who underwent F18-FDG PET/CT (PET/CT) for staging or surveillance of cancer and who were BAT-positive on PET/CT. BAT volume by PET/CT, abdominal (visceral and subcutaneous) fat and paraspinous muscle cross-sectional areas (CSA) were assessed. Groups with and without active cancer on PET/CT were compared using a two-sided paired ttest. Linear regression analyses between BAT and body composition parameters were performed.ResultsThere were 62 patients (54 female, eightmale) who had active cancer on PET/CT and 80 patients (67 female, 13male) without active cancer. Groups were similar in age and BMI (p0.4), abdominal fat and muscle CSA, fasting glucose, and outside temperature at time of scan (p0.2). Patients who had active cancer on PET/CT had higher BAT volume compared to patients without active cancer (p=0.009). In patients without active cancer, BAT was positively associated with BMI and abdominal fat depots (r=0.46 to r=0.59, p<0.0001) while there were no such associations in patients with active cancer (p0.1). No associations between BAT and age or muscle CSA were found (p0.1).Conclusions BAT activity is greater in patients with active cancer compared to age-, sex-, and BMI-matched BAT-positive patients without active cancer, suggesting a possible role of BAT in cancer activity.