Analysis of oncological safety of autologous fat grafting after immediate breast reconstruction

Background Fat grafting is now a common procedure for breast reconstruction. Many clinical studies have reported its aesthetic efficacy and oncological safety, but some experimental studies raise about the recurrence risk because of its regenerating property. This study aims to investigate the possibility of cancer recurrence associated with fat grafting. Methods In this retrospective cohort study, we analyzed a total of 339 patients who had undergone immediate reconstructive surgery after nipple-sparing mastectomy (NSM) or skin-sparing mastectomy (SSM) in our institution between February 28, 2009 and March 23, 2019. Patients who had undergone breast conserving surgery, radical mastectomy, or delayed reconstruction were excluded. We used univariate and multivariate Cox proportional hazards regression models to evaluate the association between fat grafting and cancer recurrence. Results Among the 339 patients during a median follow-up of 52 months, 27 patients (8.0%) were confirmed to have recurrent cancer. Of 67 patients who had undergone fat grafting, 10 patients were confirmed to have cancer recurrence. In multivariate analyses, fat grafting [hazard ratio (HR), 2.52; 95% CI, 1.005-6.317; P=0.0488] was independently associated with cancer recurrence. Conclusions In population of breast cancer patient who underwent immediate reconstruction in our institution, fat grafting showed significant higher risk of cancer recurrence. Although these results are at odds with many existing studies, it suggests that more careful follow-up may be necessary for patients who had undergone fat grafting after reconstructive surgery.