Evaluation of fat grafting safety in patients with intraepithelial neoplasia: a matched-cohort study.

BACKGROUND Fat grafting is widely carried out in breast cancer patients to improve quality in breast reconstruction. Recently, in vitro and animal studies have questioned the role of adipose tissues in cancer development. DESIGNS Matched-cohort study. We analysed: (i) 59 intraepithelial neoplasia patients who had undergone lipofilling, with no recurrence between primary surgery and lipofilling. (ii) A control group of 118 matched patients (two controls per lipofilling patient) with the corresponding recurrence-free intervals. Both groups were also matched for main cancer criteria. A local event (LE) was the primary end point, with follow-up starting from the baseline. RESULTS Median follow-up was 63 and 66 months from surgery, and 38 and 42 from baseline, for the lipofilling and control groups, respectively; the 5-year cumulative incidence of LE was 18% and 3% (P = 0.02). Ki-67 was the significant factor in univariate survival analysis. A subgroup analysis showed that lipofilling increased the risk of LE in women <50 years, with high grade neoplasia, Ki-67 ≥ 14 or who had undergone quadrantectomy. CONCLUSION Higher risk of LE was observed in intraepithelial neoplasia patients following lipofilling. Although further studies are required to validate our conclusions, patients belonging to this subgroup should be informed of these results and the potential risks.