Endocrine Abstracts

JOINT2809

Background: Breast cancer is the most common cancer type for women in Denmark as well as globally. There’s a large and growing group of non-metastatic breast cancer survivors, which draws more attention to long term side effects of the anti-estrogen adjuvant cancer therapy. The decrease in estrogen may thus change distribution of body fat with an increase in visceral fat. The aim of this observational study is to assess potential side effects of aromatase inhibitors on the body composition on postmenopausal women with early-stage breast cancer.

Methods: A cohort of postmenopausal women with early breast cancer (EBC) were examined post chemotherapy (baseline), and after 12 months of aromatase inhibitor treatment, and compared to an age- and postmenopausal status matched healthy control group (CON). The examination was done with dual energy X-ray absorptiometry (DXA) scans. We excluded patients with known prior malignancy, pre-existing endocrine diseases and pre-existing diseases that can affect cancer or the endocrine system.

Results: We included 15 EBC participants and 8 controls. The mean age was for EBC 59. 1 (±5. 1), and for CON 60. 8 (±3. 3). As expected, there was no difference in body composition between EBC and CON at baseline: visceral adipose tissue (VAT) EBC 396. 7g (±200), CON 334, 1g (±173) p>0. 05; fat mass (FM) EBC 29. 0kg (±9. 2), CON 26. 5kg (±7. 0) p>0. 05; fat% EBC 37. 4% (±5. 3), CON 36. 3% (±4. 9) p>0. 05; lean body mass (LBM) EBC 45. 5kg (±8. 5), CON 44. 1kg (±5. 9) p>0. 05). There were no changes in body composition from baseline to 12 months (mean change (95% CI)), VAT (EBC +47. 8g (-63. 5-159. 1), p>0. 05; CON +71. 6g (-42. 7-186. 0), p>0. 05), FM (EBC -0. 5kg (-2. 7-1. 7), p>0. 05; CON -1. 6kg (-4. 3-1. 1), p>0. 05), fat% (EBC +0. 8%-points (-0. 6-2. 3), p>0. 05; CON -1. 3%-points (-3. 0-0. 5), p>0. 05) and LBM (EBC -0. 8kg (-2. 0-0. 4), p>0. 05; CON -0. 1kg (-3. 0-2. 8), p>0. 05).

Conclusion: These preliminary results suggest no interaction between 12 months of aromatase inhibitor treatment post chemotherapy and body composition, where no changes was found between the two groups nor within the groups.