Abstract PS1-22: The oncological safety of lipofilling after breast cancer surgery: A meta-analysis
Authors: Goncalves Rodrigo , Mota Bruna S , Sobreiro-Lima Bruno , Ricci Marcos D , Soares José M , Baracat Edmund C , Filassi José R 
Published: February 2021

INTRODUCTION Autologous fat grafting (AFG) for the purpose of breast reconstruction presents difficulties during follow-up radiological exams and the oncological potential of grafted fat is uncertain. Coleman et al in 2007 confirmed that, provided a rigorous protocol is respected, the fatty tissue could be transferred under good conditions and would not interfere with mammographic follow-up, although the issue remains controversial about the oncological safety. This study aims to analyze the oncological safety of lipofilling through a meta-analysis of the current literature. METHODS We conducted a meta-analysis to evaluate the oncological safety of AFG after breast cancer (BC) surgery. We reviewed the literature published until 07/05/2020. The outcomes were overall survival (OS), disease free-survival (DFS) and local recurrence (LR). We included RCTs, cohort studies, case-control studies that evaluated women with BC diagnosis who undergone surgery followed by reconstruction with AFG. This review was performed in accordance with the PRISMA guidelines and we searched the electronic databases of Medline, EMBASE and LILACS, using the MeSH terms for AFG and BC. There was no language restriction. Methodological quality was assessed using the Downs and Black instrument and evidence quality by GRADE. We synthesized data using the inverse variance method on the log-HR scale for time-to-event outcomes using RevMan. We assessed the presence of statistical heterogeneity using the Chi2 statistic and we investigated its extension by the use of I2 statistic. RESULTS We identified 624 references. Of these, 16 studies fulfilled our eligibility criteria and were included. Funnel plot analysis revealed no publication bias. There were 8667 patients included and their mean age was 49 years. The breast surgery indications were invasive breast carcinoma (66.1%), carcinoma in situ (18.4%) and prophylactic reasons (15,5%). Ten out of 16 studies described the technique used to perform the AFG as Coleman’s. In 9 out 16 studies there was no difference in adjuvant treatment between groups, two studies do not mention if there was any difference and in 4 studies there were different adjuvant treatments in control and intervention arms. Quality assessment resulted in 11 studies being considered ‘good’, 4 studies were considered ‘fair’ and 1 study was considered poor. The HR could be extracted from four studies and an increase of OS for lipofilling group was detected with high heterogeneity (HR 0.47, 95% CI 0.32 to 0.7, p=0.0002, 2331 patients, I2= 84%, high certainty evidence). Funnel plot analysis indicated a high risk of publication bias from one study, Krastev et al, which included 587 patients. The analysis excluding this article found no difference in OS between lipofilling group and control and publication bias was not detected (HR 0.9, 95% CI 0.53 to 1.54, p=0.71, 1744 patients, I2= 58%, high certainty evidence). The HR for DFS could be extracted from six studies and no difference was found between lipofilling group and control (HR 1.01, 95% CI 0.73 to 1.38, p=0.96, 2755 patients, I2= 0%, high certainty evidence). The HR for LR could be extracted from ten studies and no difference was found between lipofilling group and control (HR 0.86, 95% CI 0.66 to 1.12, p=0.43,6839 patients, I2= 1%, moderate certainty evidence). Funnel plot analysis indicated a publication bias from one study (Petit et al) that included only DCIS tumors. The analysis excluding this article did not demonstrate difference in results. (HR 0.8, 95% CI 0.61 to 1.05, p=0.94, 6662 patients, I2= 0%, moderate certainty evidence) CONCLUSION Based on published data, AFG is a safe technique of breast reconstruction for patients that undergone BC surgery. According to our findings, AFG did not affect OS, DFS or LR. These data have moderate to high certainty and additional studies probably will not change the current evidence.

Citation Format: Rodrigo Goncalves, Bruna S Mota, Bruno Sobreiro-Lima, Marcos D Ricci, José M Soares, Jr, Edmund C Baracat, José R Filassi. The oncological safety of lipofilling after breast cancer surgery: A meta-analysis [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-22.