Abstract Background: There is concern from in-vitro studies that adipose-derived stem cells could promote cancer recurrence through their proliferative properties. The impact of immediate lipofilling (ILF) in the setting of breast conserving surgery on oncological outcomes, complications and patient-reported outcomes are unknown. Methods: A systematic search of Medline, Embase and Cochrane Central was conducted for studies investigating the impact of ILF in patients undergoing BCS. Random-effects meta-analysis were conducted for oncological outcomes (local LR, regional RR, distant DR and overall recurrence). Results: Six studies fulfilled the inclusion criteria including 252 patients. The pooled LR, RR, DR and overall recurrence rates were 2.38%, 1.52%, 3.03% and 5.95%, respectively (median follow-up, 39 months). A meta-analysis of studies comparing ILF (n=170) with no-ILF (n=362) found no difference in LR (OR, 0.77; 95%CI, 0.19-3.17; p=0.714), RR (OR 1.73, 95%CI 0.36-8.21, p=0.686), DR (OR 1.37, 95%CI, 0.51-3.63; p=0.627) or overall recurrence (OR 1.23, 95%CI, 0.60-2.52; p=0.569). Cancer-specific survival in the ILF group was 100% compared to 98.7% with no ILF. Post-operative calcifications (12.9% 21/163 vs. 0%; 0/72, p=0.002) and fat necrosis (7.8% (17/217] vs. 2.8% 8/283, p=0.011) were significantly more common with ILF, but early complications (e.g haematoma and infection) showed no difference (p0.05). Three studies reported superior Breast-Q scores in ILF compared to no-ILF. No randomised controlled trials have been conducted. Conclusion: Immediate lipofilling following BCS is oncologically safe, enhances aesthetic outcomes and causes minimal morbidity. Citation Format: J. Lucocq, H. Baig, J. Dixon. The impact of immediate lipofilling on oncological outcomes, complication rates and patient reported outcomes in breast conserving surgery: a systematic review and meta-analysis abstract. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS3-13-08.
Lucocq et al. (Tue,) studied this question.