Modification of abdominal fat distribution after aromatase inhibitor therapy in breast cancer patients visualized using 3-D computed tomography volumetry

Abstract

Introduction/background: The purpose of this study was to describe modification of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) distributions in breast cancer patients after aromatase inhibitor (AI) therapy using computed tomography (CT) volumetric measurement of abdominal body fat distribution.

Patients and methods: Sixty-four consecutive patients who were receiving adjuvant AI therapy were included in this study. Patients were evaluated using CT before and after at least 6 months of AI therapy with imaging follow-up of 4.3 ± 2.2 years. Abdominal fat distribution was automatically calculated using a workstation that obtained total abdominal adipose tissue (TAAT) area (mm(3)). SAT was manually segmented and VAT was determined as TAAT - SAT. Percentages were calculated for change of TAAT, VAT, and SAT. VAT/SAT ratio was calculated.

Results: Percentage of TAAT after AI therapy was increased by a mean of 9.1% from baseline (16,280.3 ± 6953.3 mm(3)) to (17,763.6 ± 6850.8 mm(3)). Two groups of patients were observed; those with an increase in TAAT and those with a decrease. Modification of VAT/SAT ratio was observed (from 1.38 to 1.69) in all subjects, reflecting a relative increased volume of VAT (mean, 18%) and slight mean reduction of SAT (mean 1.9%).

Conclusion: In our study, therapy with AI in breast cancer patients was accompanied with a change in fat distribution to relatively greater VAT/SAT ratio in patients, regardless of whether they gained or lost weight after therapy. Because this pattern of fat distribution is associated with metabolic disorders, attention must be paid to these clinical manifestations in patients during their follow-up management.

Keywords: Aromatase inhibitor therapy; Breast cancer; CT; Subcutaneous fat; Visceral fat.