Abstract P6-14-01: Evaluation of the oncologic safety of autologous fat transfer after a total mastectomy and immediate reconstruction for breast cancer
Authors: Omalek Donia , Chaltiel Leonor , Vaysse Charlotte , Gangloff Dimitri , Meresse Thomas , Chaput Benoit , Jouve Eva , Selmes Gabrielle 
Published: March 2020

Abstract
Introduction: Autologous fat transfer (AFT) is widely used to improve results of breast reconstructive surgery. But its safety has been controversial. Heterogeneous studies, in which AFT has been used in different clinic situations (breast augmentation, after prophylactic surgery, with radical or partial breast cancer surgery) led the High Autority of Health in France in 2015 to publish precautionary measures for its use after radical mastectomy. Our objective is to evaluate the oncologic safety of AFT in a homogeneous population of patients who underwent a total mastectomy with immediate reconstruction for breast cancer.
Methods: Our unicentric retrospective cohort study concerns a consecutive cases serie of total mastectomy with immediate reconstruction for breast cancer between 2007 and 2015 at the Institut Universitaire du Cancer de Toulouse. An analysis in landmark has been used to evaluate the effect of AFT on the living patients without events at 24 months.
Results: 628 cases of mastectomies have been included; and 550 cases were analyzed with the landmark method. The majority (84,5%) got an implant reconstruction. 136 (24,7%) underwent at least 1 fat graft transfer. 62,5 % of these patients had only one AFT. The two groups of patients, with and without AFT, were comparable for disease stage with respectively: Tumor stage: Tis 26,5% vs 34,3%; T1 60,3% vs 50,4%; T2 11,8% vs 13,1% (p = 0,2026); nodal involvement 22,1% vs 23,5 %; histologic luminal sub type (RH+/her2 -) 77,3% vs 74,3% (p = 0,5612). They were also similar for adjuvant treatment with respectively: chemotherapy for 27,2 % vs 30,7 % (p = 0,4427), radiotherapy for 30,9% vs 31,9% (p=0,8275), hormonotherapy 60,7% vs 54,1% (p=0,1778). Median follow up was 55,2 months (95% IC [52.9;57.7]). Disease free survival (DFS) was 90,4%. There was no difference for DFS between the 2 groups: 92,32% [88.75;94.79] for the group without AFT and 90,91 % [81.01;95.78] for the AFT group (p = 0,9569). In subgroups analysis, for the patients which had undergone a AFT, there was no difference of DFS for the patients younger than 50 years old 89,82% vs 86,09 %; (p = 0,7079), the ones with high grade intra ductal carcinoma 92,27% vs 89,83%; p = 0,6189). Only patients with nodal involvement who underwent a fat graft transfer within 24 months, had a lower DFS: 69,15% than the patients without nodal involvement 92,46% (p=0,0351).
Conclusion: Autologous fat transfer used within the 24 months after total mastectomy for breast cancer and immediate reconstruction does not change disease free survival. Complementary analysis must be done in case of nodal involvement.
Citation Format: Donia Omalek, Leonor Chaltiel, Charlotte Vaysse, Dimitri Gangloff, Thomas Meresse, Benoit Chaput, Eva Jouve, Gabrielle Selmes. Evaluation of the oncologic safety of autologous fat transfer after a total mastectomy and immediate reconstruction for breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-14-01.