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

Oncologic safety of autologous fat grafting in primary breast reconstruction after mastectomy for cancer

INTRODUCTION

Autologous fat transfer (AFT) is widely used to improve results of breast reconstructive surgery, but its safety is controversial. Our objective was 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

We performed a retrospective cohort study by identifying all patients who underwent immediate breast reconstruction after mastectomy for breast cancer from 2007 to 2015 in our center. A patient group with AFT performed in the 24 months after mastectomy was compared to a control group.

RESULTS

Five hundred fifty cases were included, of whom 136 (24.7%) underwent at least one fat graft transfer. Median age was 51 years. Reconstruction was performed in 465 (84.5%) with an implant reconstruction. The median time from mastectomy to AFT was 13.8 months. The median follow up was 55.2 months. A total of 53 events were observed, including 10 (7.4%) in the AFT group and 43 (10.4%) in the control group. There was no difference in 5-year recurrence-free survival (RFS) between the groups. In the subgroup analysis, only lymph node involvement in patients who underwent AFT in the first 24 months after oncologic surgery appeared as a risk factor of recurrence. Among the 104 patients with lymph node involvement, 5-year RFS was 69.2% in patients with lipofilling vs 92.5% in patients without it (p = 0 0.0351).

CONCLUSION

Performing early lipofilling in primary breast reconstruction after mastectomy for cancer seems to be oncologically safe. Lymph node involvement increases the risk of recurrence in this population.

The oncological safety and long-term cosmetic effect of free dermal fat graft with epidermis removal for breast defect repair in breast conserving surgery

BACKGROUND

Free dermal fat grafts (FDFG) are used for immediate breast defect repair in breast-conserving surgery (BCS), and have achieved satisfactory immediate postoperative cosmetic effects (Sawai et al., 2004) [1]. However, the oncologic safety and long-term cosmetic outcomes of these surgical procedures remain unknown. Therefore, t，in this study, we aim to investigate the oncological safety and long-term cosmetic outcomes of FDFG in patients with breast cancer.

METHODS

This matched retrospective case-control study included patients with non-special types of breast cancer who underwent FDFG for breast defect repair after BCS or BCS alone at two breast cancer research centers in Guangxi Province, China, from January 2016 to December 2019. The patients were divided into either the FDFG or BCS group. Control cases were screened using propensity score matching, and survival analysis and cosmetic evaluations were performed.

RESULTS

A total of 442 patients with breast cancer were included in the study. After 1:4 propensity score matching, 53 and 212 patients were included in the FDFG and BCS groups, respectively. The median follow-up time was 49.9 (9.0-76.0) months. The rate of local recurrence in the FDFG group (9.4 %) was significantly higher than that in the BCS group (1.9 %; p < 0.05). The total cosmetic evaluation score was significantly higher in the BCS group 18 months after surgery than in the FDFG group (p < 0.05).

CONCLUSIONS

In this retrospective study, FDFG was significantly associated with an increased risk of local recurrence. Further prospective studies are required to confirm these results. No significant difference in long-term cosmetic effects were observed for FDFG than for BCS alone for immediate breast defect repair.

Oncological Safety of Autologous Fat Grafting for Breast Reconstruction

BACKGROUND

Autologous fat grafting has become a vital component of breast reconstruction. However, concerns remain regarding the safety of fat grafting after oncological resection and breast reconstruction. The purpose of the study was to evaluate the association of fat grafting after breast reconstruction with metastasis and death in breast cancer patients.

METHODS

A retrospective, population-based cohort study was conducted using deidentified claims data from 2001 to 2018 and included privately insured patients with breast cancer who underwent breast reconstruction after surgical resection. Breast reconstruction patients who underwent fat grafting were compared with those not undergoing fat grafting, evaluating metastasis and death up to 15 years after reconstruction. One-to-one propensity score matching was used to account for selection bias on patient risk factors comparing those with and without fat grafting.

RESULTS

A total of 4709 patients were identified who underwent breast reconstruction after lumpectomy or mastectomy, of which 368 subsequently underwent fat grafting. In the propensity score-matched patients, fat grafting was not associated with an increased risk of lymph node metastasis (9.7% fat-grafted vs 11.4% in non-fat-grafted, P = 0.47) or distant metastasis (9.1% fat-grafted vs 10.5% in non-fat-grafted, P = 0.53). There was no increased risk of all-cause mortality after fat grafting for breast reconstruction (3.9% fat-grafted vs 6.6% non-fat-grafted, P = 0.10).

CONCLUSIONS

Among breast cancer patients who subsequently underwent fat grafting, compared with no fat grafting, no significant increase was observed in distant metastasis or all-cause mortality. These findings suggest that autologous fat grafting after oncologic resection and reconstruction was not associated with an increased risk of future metastasis or death.

Optimizing Prepectoral Implant Placement and Concomitant Fat Grafting After Tissue Expansion

BACKGROUND

Prepectoral implant-based breast reconstruction is often supplemented by autologous fat grafting to optimize aesthetic outcomes. This usually entails several rounds of modest fat transfer to minimize risk of necrosis; however, the limits of fat grafting at expander exchange are not known.

METHODS

A single-institution retrospective review from July 2016 to February 2022 was performed of all patients who underwent (1) mastectomy, (2) prepectoral tissue expander placement, (3) expander exchange for implant, and (4) at least one round of autologous fat transfer. Student t test and χ2 test were used.

RESULTS

A total of 82 breasts underwent a single round of fat grafting during implant placement (group 1); 75 breasts underwent fat grafting that occurred in multiple rounds and/or in delay to implant placement (group 2). Group 1 received more fat at the time of implant placement (100 mL; interquartile range, 55-140 mL; P < 0.001) and underwent fewer planned operative procedures compared with group 2 (1.0 vs 2.2, P < 0.001). Total fat volume in group 2 did not significantly exceed that of group 1 until after 3 rounds of fat transfer (128.5 mL; interquartile range, 90-130 mL; P < 0.01). There was no difference in the rate of fat necrosis between groups after the first round (15.9% vs 9.3%, P = 0.2) and final round (15.9% vs 12.0%, P = 0.5) of fat grafting. Complication rates were similar between groups (3.7% vs 8.0%, P = 0.2).

CONCLUSIONS

A 2-stage approach of prepectoral tissue expander placement with single round of larger volume fat transfer at expander exchange reduces overall number of operative procedures without increased risks.

Free Flap Fat Volume is Not Associated With Recurrence or Wound Complications in Oral Cancer

Objective

Adipose stem cells (ASCs) have been shown in many preclinical studies to be potent suppressors of the immune system. Prior studies suggest that ASCs may promote cancer progression and wound healing. However, clinical studies investigating the effects of native, or fat-grafted adipose tissue on cancer recurrence have generated mixed results. We investigated whether adipose content in reconstructive free flaps for oral squamous cell carcinoma (OSCC) is associated with disease recurrence and/or reduction in wound complications.

Study Design

Retrospective chart review.

Setting

Academic medical center.

Methods

We performed a review of 55 patients undergoing free flap reconstruction for OSCC over a 14-month period. Using texture analysis software, we measured the relative free flap fat volume (FFFV) in postoperative computed tomography scans and compared fat volume with patient survival, recurrence, and wound healing complications.

Results

We report no difference in mean FFFV between patients with or without recurrence: 13.47 cm³ in cancer-free survivors and 17.99 cm³ in cases that recurred (p = .56). Two-year recurrence-free survival in patients with high and low FFFV was 61.0% and 59.1%, respectively (p = .917). Although only 9 patients had wound healing complications, we found no trend in the incidence of wound healing complications between patients with high versus low FFFV.

Conclusion

FFFV is not associated with recurrence or wound healing in patients undergoing free flap reconstruction for OSCC, suggesting adipose content should not be of concern to the reconstructive surgeon.

The effect of radiotherapy on fat engraftment for complete breast reconstruction using lipofilling only

PURPOSE

Lipofilling has been established as a standard technique for contour enhancement following breast reconstruction. However, there is a paucity in current literature regarding the use of this technique for complete reconstruction of the female breast as an alternative to conventional techniques, such as expander or flap-based procedures. In particular, the influence of pre-operative irradiation for successful reconstruction has rarely been examined in published studies. Here, the authors describe their experience with successful fat injection in pre-radiated breasts in comparison with non-pre-radiated patients.

METHODS

In this retrospective study, we examined a total of 95 lipofilling treatments on 26 patients (28 breasts). All of them experienced mastectomy following breast cancer; local breast defects after partial resection of the gland were not included in this study. In total, 47 lipofilling procedures in 12 non-irradiated patients (14 breasts) and 48 procedures in 14 irradiated women (also 14 breasts) were performed. Per session, approximately 297 ± 112 cc of adipose tissue was grafted in group A (no radiotherapy) and approximately 259 ± 93 cc was grafted in group B (radiotherapy).

RESULTS

Among the group of women without pre-operative radiation, 71% of breast reconstructions limited to lipofilling only showed constant engraftment of fat tissue with a successful reconstructive result, whereas only 21% of the patients with pre-radiated breasts showed complete reconstruction of the breast with a permanent fat in-growth.

CONCLUSION

Preoperative radiotherapy significantly impedes successful completion of breast reconstructions planned only by autologous fat transfer. Patients should be selected individually and carefully for complete breast reconstruction using lipofilling only.

Meta-Analysis of the Oncological Safety of Autologous Fat Grafting After Breast Cancer on Basic Science and Clinical Studies

BACKGROUND

The purpose of the present study was to comprehensively evaluate the oncological safety of autologous fat grafting after breast cancer by combining experimental and clinical studies.

METHODS

All studies published before August 2021 were collected by searching PubMed, Cochrane, Embase, Web of Science, SINOMED, and China National Knowledge Infrastructure. After screening the research and extracting the data, RevMan was used to perform the meta-analysis.

RESULTS

Five basic science studies and 26 clinical studies, involving a total of 10,125 patients, were eventually included. In the basic science studies, adipose-derived stem cells promoted breast cancer growth, but fat grafting and adipose-derived stem cells plus fat grafting were not associated with breast cancer growth. An overall analysis of clinical studies showed that autologous fat grafting does not increase the risk of breast cancer recurrence. Subgroup analyses indicated that autologous fat grafting did not increase the risk of breast cancer recurrence in Asian or Caucasian patients, in patients undergoing breast-conserving surgery or modified radical mastectomy, in patients with in situ carcinomas or invasive carcinomas, or in patients undergoing postoperative radiotherapy.

CONCLUSION

This study combined experimental and clinical studies to conclude that autologous fat grafting does not increase the risk of breast cancer recurrence. However, the experimental results suggest that adipose-derived stem cells should be used with caution after breast cancer surgery.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Breast Autologous Fat Transfer Entirely Under Tumescent Anesthesia: Safety and Efficacy

BACKGROUND/OBJECTIVES

The prior use of external expansion has been described in the literature as a tool to allow reliable grafting of more than 200 mLs of autologous fat under general anesthesia. The purpose of this study was to determine whether breast autologous fat transfer entirely under tumescent anesthesia (BAFTEUTA) is a safe and effective technique.

METHODS

After institutional board approval, 22 consecutive patients were enrolled in this single-cohort, prospective study. All patients underwent preoperative expansion using manually evacuated domes. All procedures were performed under tumescent anesthesia with oral sedation.

RESULTS

There was a median successful graft of 200 mLs. Complications were minimal and limited to occlusive folliculitis.

CONCLUSION

Although the author has not reported as large graft volumes as some other authors, BAFTEUTA is a safe procedure and can have good outcomes with high levels of patient satisfaction.

Review of Autologous Fat Grafting in Postmastectomy Reconstruction Patients: Nonroutine Diagnostics and Oncologic Safety

Autologous fat grafting (FG) is increasingly used as an adjunctive reconstruction technique to augment volume, achieve symmetry, and improve contour deformities. This study aims to characterize the oncologic and surgical safety of FG in women undergoing autologous breast reconstruction (ABR) or implant-based reconstruction (IBR).

METHODS

A retrospective chart review was performed for all patients undergoing FG at a multi-site single health system between 2015 to 2018. A total of 228 eligible breasts from 155 patients were identified using Current Procedural Terminology codes. Patients were divided by reconstructive technique. Bivariate analyses compared baseline characteristics and post-FG outcomes.

RESULTS

Mean age for patients undergoing ABR (129 breasts) was 52.8 years compared to 48.6 years for those undergoing IBR (99 breasts; P = 0.002). A heavier volume of fat was grafted per ABR breast (143.8mL) than per IBR breast (102.2mL; P = 0.002). Forty-seven (20.6%) breasts required FG revision, more frequently in ABR breasts (31.0%) than IBR breasts (7.1%; P < 0.001). Following FG, 17.5% of patients experienced a palpable mass, and 18.9% of breasts underwent nonroutine diagnostics or procedures, with no difference between ABR and IBR groups. Most biopsies noted benign findings such as fat necrosis (2.2%) or a benign mass (0.9%), with recurrence only noted in two patients (0.9%). Mean follow-up was 20.4 months.

CONCLUSION

FG is a safe, surgically simple procedure more commonly performed in ABR breasts. FG use in ABR and IBR breasts is oncologically safe, with no impairment in breast surveillance and low rates of locoregional recurrence, but possibly increased incidence of nonroutine imaging and biopsies.

The relationship between immediate postmastectomy reconstruction modalities and survival benefits in patients with triple negative breast cancer

INTRODUCTION

Immediate postmastectomy reconstruction for breast cancer has been widely used due to its unique esthetic and psychological effects. However, no other population-based study has investigated the effects of different reconstruction types on the survival in patients with triple negative breast cancer (TNBC).

METHODS

We selected patients who met the eligibility criteria from the Surveillance, Epidemiology, and End Results cancer registry (N = 9760). We then assessed the effect of different reconstructive surgical approaches (implant, autologous, implant and autologous combined reconstruction) on the overall survival (OS) and breast cancer-specific survival (BCSS) by using the Kaplan-Meier survival curve and Cox proportional hazard regression analyses. The nomograms were used to predict OS and BCSS. And the competitive risk model was used to assess breast cancer-specific death (BCSD) and non-breast cancer-specific death (NBCSD).

RESULTS

Statistical analysis suggested that the three reconstruction methods had better OS and BCSS with lower hazard than mastectomy alone (log-rank test, p < 0.05). Multivariate stratified analysis showed that patients aged 40-60 years had the greatest improvement in OS (Adjusted hazard ratio [AHR], 0.646; 95% Confidence Interval [CI], 0.439-0.950; p = 0.026) with combined reconstruction. BCSS could be improved only by implant reconstruction (AHR, 0.672; 95% CI, 0.514-0.878; p = 0.004). In addition, autologous reconstruction (AHR, 0.570; 95% CI, 0.350-0.929; p = 0.024) and implant reconstruction (AHR, 0.538; 95% CI, 0.339-0.853; p = 0.008) improved OS in patients >60 years of age. The survival prediction model quantified the survival benefits of TNBC patients undergoing different surgeries. Moreover, the C-indexes showed the good predictive ability of the nomograms.

CONCLUSIONS

Our results suggest that for TNBC patients, there is a survival benefit of immediate postmastectomy reconstruction compared with mastectomy alone. Among them, implant reconstruction has the most obvious advantage.

SINGLE-CENTER ONCOLOGIC OUTCOME OF FAT TRANSFER FOR BREAST RECONSTRUCTION FOLLOWING MASTECTOMY IN 1000 CANCER CASES - A MATCHED CASE-CONTROL STUDY

BACKGROUND

Autologous fat transfer (AFT) has an important role in breast reconstructive surgery. Nevertheless, Some concerns remain with regards to its oncological safety. We present a single center case-matching study analysing the impact of AFT in cumulative incidence of local recurrences (LR).

MATERIALS AND METHODS

From a prospectively maintained database, we identified 902 patients who underwent 1025 breast reconstructions from 2005 to 2017. Data regarding demographics, tumor characteristics, surgery details and follow-up were collected. Exclusion criteria were patients with distant metastases at diagnosis, recurrent tumor or incomplete data regarding primary tumor, patients who underwent prophylactic mastectomies and breast-conserving surgeries. Statistical analysis was done to evaluate the impact of the variables on the incidence of LR. A p-value < 0.05 was considered statistically significant.

RESULTS

After 1:n case-matching, we selected 919 breasts, out of which 425 (46.2%) patients received at least one AFT session vs 494 (53.8%) control cases. LR had an overall rate of 6.8% and we found LR in 14 (3.0%) AFT cases and 54 (9.6%) controls. Statistical analysis showed that AFT did not increase risk of LR: HR 0.337 (CI 0.173-0.658), p=0.00007. Multivariate analysis identified IDC subtype and lymph node metastases to have an increased risk of local recurrences (HR > 1). Conversely, positive hormonal receptor status was associated with a reduced risk of events (HR < 1).

CONCLUSIONS

AFT was not associated with a higher probability of locoregional recurrence in patients undergoing breast reconstruction therefore it can be safely used for total breast reconstruction or aesthetic refinements.LEVEL OF EVIDENCE: 3.

An In Vitro Approach for Investigating the Safety of Lipotransfer after Breast-Conserving Therapy

The application of lipotransfer after breast-conserving therapy (BCT) and irradiation in breast cancer patients is an already widespread procedure for reconstructing volume deficits of the diseased breast. Nevertheless, the safety of lipotransfer has still not been clarified yet due to contradictory data. The goal of this in vitro study was to further elucidate the potential effects of lipotransfer on the irradiated remaining breast tissue. The mammary epithelial cell line MCF-10A was co-cultured with the fibroblast cell line MRC-5 and irradiated with 2 and 5 Gy. Afterwards, cells were treated with conditioned medium (CM) from adipose-derived stem cells (ADSC), and the effects on the cellular functions of MCF-10A cells and on gene expression at the mRNA level in MCF-10A and MRC-5 cells were analyzed. Treatment with ADSC CM stimulated transmigration and invasion and decreased the surviving fraction of MCF-10A cells. Further, the expression of cytokines, extracellular, and mesenchymal markers was enhanced in mammary epithelial cells. Only an effect of ADSC CM on irradiated fibroblasts could be observed. The present data suggest epithelial–mesenchymal transition-like changes in the epithelial mammary breast cell line. Thus, the benefits of lipotransfer after BCT should be critically weighed against its possible risks for the affected patients.

Systematic review: Oncological safety of reconstruction with fat grafting in breast cancer outcomes

BACKGROUND

Autologous fat grafting (AFG) has become a commonly used procedure for breast reconstruction (BR) after cancer removal. Nevertheless, oncological considerations remain for AFG after breast cancer surgery.

OBJECTIVES

This article aims to evaluate the oncological safety of AFG in BR and its effect on disease-free survival (DFS) and local-regional recurrences (LRR).

METHODS

A systematic review regarding the use of AFG in BR to identify a difference in incidence rates of LRR and DFS between patients who had AFG and controls was performed using PubMed, MEDLINE, Embase, PreMEDLINE, Ebase, CINAHL, PsycINFO, Clinicaltrials.gov, Scopus, and Cochrane databases. The protocol was developed following the Preferred Reporting for Items for Systematic Reviews-Protocols (PRISMA-P) guidelines. The included studies had to match predetermined criteria according to the PICOS approach.

RESULTS

A total of 11 studies were included. Seven studies reported LRR, and 5 studies reported DFS in 5,886 patients. Our systematic review showed that AFG was not associated with increased LRR and DFS. Pooled hazard ratios (HRs) (95% confidence intervals [CIs]) for LRR and DFS were 1.26 (0.90-1.76) and 1.27 (0.96-1.69), respectively.

CONCLUSIONS

AFG can, therefore, be performed safely in BR after breast cancer. Further, randomized controlled trials and related systematic reviews, as well as evidence-based medicine (EBM) studies of level 1, are required to consolidate the results of the studies identified in this systematic review.

Reverse Expansion Following Nipple Sparing Mastectomy: A Natural, Safe and Effective Autologous Technique for Breast Reconstruction

The majority of surgeons choose an implant-based breast reconstruction after mastectomy. Nevertheless, lipofilling is a constantly growing technique allowing a complete breast reconstruction without prosthesis. We introduce our experience using reverse expansion for breast reconstruction following a nipple-sparing mastectomy (NSM) with a subpectoral skin expander. In the period January 2010-August 2021, 106 breast reconstruction procedures were performed on 50 patients after a NSM. We harvested an amount of fat tissue using a 2.5 mm liposuction cannula, we centrifuged it 3 min at 4000 rpm and injected in the recipient site using 3 ml syringes and Coleman cannulas. At the beginning of every session, the breast expander was deflated of a saline volume similar to the one of the fat to be injected. We harvested an average of 679.2 ccs of fat per session and injected an average of 319.3 ccs per breast. The mean number of sessions has been 2.4 per breast. The average number of sessions in a radiotreated patients' subgroup has been slightly higher than a control group. The mean follow-up time was 63.5 months and we observed no complications in 105 over 106 procedures. Lipofilling has proven to be a safe and effective technique for complete breast reconstruction. Our procedure considers the use of a breast expander as a device to prepare the recipient site. Reverse expansion after a NSM allows a like-with-like reconstruction and it might be the first reconstructive choice in a selected group of patients.Level of Evidence IV This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Oncological safety of reconstruction with autologous fat grafting in breast cancer patients: a systematic review and meta-analysis

To evaluate the oncological safety of autologous fat grafting and its effect on disease-free survival and local recurrence in breast cancer patients with autologous fat grafting (AFG) reconstruction. A literature search was performed using the Pubmed, Medline, Web of Science, and Cochrane libraries from January 2011 to March 2020, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, to identify all relevant studies involving the application of autologous fat grafting in breast cancer reconstruction procedures. The primary outcome of the meta-analysis was a difference in incidence rates of locoregional recurrence and disease-free survival (DFS) between patients who had autologous fat grafting and controls. A total of 11 studies were included. Eight studies reported local-regional recurrences (LRR) and five studies reported disease-free survival (DFS) in 5,886 patients. Our meta-analysis of all included studies about survival outcomes showed AFG was not associated with increased LRR and DFS. Pooled hazard ratios (HRs) (95% CIs) for LRR and DFS were 1.26 (0.90-1.76) and 1.27 (0.96-1.69), respectively. According to the published literature, autologous fat grafting did not result in an increased rate of LRR and DFS in patients with breast cancer. Autologous fat grafting can, therefore, be performed safely in breast reconstruction after breast cancer.

Oncological Safety of Autologous Fat Grafting in Breast Reconstruction: A Meta-analysis Based on Matched Cohort Studies

BACKGROUND

Autologous fat grafting has become a commonly used procedure for breast reconstruction after breast cancer surgical treatment. Nevertheless, oncological considerations remain concerning autologous fat grafting after breast cancer surgery.

OBJECTIVE

This meta-analysis aimed to summarize the current matched cohort studies and provide high-quality evidence-based conclusions on the oncological safety of fat grafting in breast reconstruction.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines were followed. A literature search was performed on August 1, 2021, using PubMed. All relevant matched cohort studies of patients undergoing autologous fat grafting after breast cancer surgery were included. After independently screening the studies and extracting the data, pooled estimates for local and regional recurrence as well as distant metastases were conducted using Review Manager software (RevMan, version 5.3). Outcomes were expressed as odds ratios and 95% confidence intervals.

RESULTS

Seventeen studies involving 7494 patients were included. The observed outcomes indicated that no significant differences existed in the risks of local and regional recurrence or distant metastases between autologous fat grafting and control groups. Also, there was no significant heterogeneity among the studies.

CONCLUSION

This study provided evidence-based conclusions that support the use of autologous fat grafting in breast reconstruction.

LEVEL OF EVIDENCE III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The oncological safety of autologous fat grafting: a systematic review and meta-analysis

Objective

To present a systematic review of the literature and a meta-analysis evaluating the oncological safety of autologous fat grafting (AFG).

Summary background data: AFG for breast reconstruction presents difficulties during follow-up radiological exams, and the oncological potential of grafted fat is uncertain. Previous studies confirmed that the fatty tissue could be transferred under a good condition suitable would not interfere with mammographic follow-up, although the issue of oncological safety remains.

Methods

We reviewed the literature published until 01/18/2021. The outcomes were overall survival (OS), disease-free survival (DFS), and local recurrence (LR). We included studies that evaluated women with breast cancer who undergone surgery followed by reconstruction with AFG. We synthesized data using the inverse variance method on the log-HR (log of the hazard ratio) scale for time-to-event outcomes using RevMan. We assessed heterogeneity using the Chi² and I² statistics.

Results

Fifteen studies evaluating 8541 participants were included. The hazard ratios (HR) could be extracted from four studies, and there was no difference in OS between the AFG group and control (HR 0.9, 95% CI 0.53 to 1.54, p = 0.71, I² = 58%, moderate certainty evidence), and publication bias was not detected. The HR for DFS could be extracted from six studies, and there was no difference between the AFG group and control (HR 1.01, 95% CI 0.73 to 1.38, p = 0.96, I² = 0%, moderate certainty evidence). The HR for LR could be extracted from ten studies, and there was no difference between the AFG group and control (HR 0.86, 95% CI 0.66 to 1.12, p = 0.43, I² = 1%, moderate certainty evidence).

Conclusion

According to the current evidence, AFG is a safe technique of breast reconstruction for patients that have undergone BC surgery and did not affect OS, DFS, or LR.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09485-5.

Effects of Breast-Conserving Surgery Combined with Immediate Autologous Fat Grafting on Oncologic Safety, Satisfaction and Psychology in Patients with Breast Cancer: A Retrospective Cohort Study

Purpose

Autologous fat grafting (AFG) is a technique that can improve the appearance of breasts in surgical patients. There are currently few studies on breast-conserving surgery (BCS) combined with immediate AFG, although we believe that it could achieve satisfactory effects. Therefore, the purpose of this study is to observe the effects of BCS combined with immediate AFG on oncologic safety, satisfaction and psychology of breast cancer patients.

Patients and Methods

We retrospectively collected the data of 85 breast cancer patients from February 2018 to October 2018. After screening, 40 patients in AFG group (AG, BCS combined with immediate AFG) and 40 patients in control group (CG, BCS alone) were finally included in the study. The primary outcomes were the survival, tumor recurrence and metastasis, and BREAST-Q score of patients. The secondary outcomes were short and long-term complications, degree of depression and anxiety of patients.

Results

A total of 80 patients were included in the analysis. There was no significant difference in the clinicopathological data between the two groups (P>0.05). The average follow-up time of the two groups was 40.58±2.630 and 40.28±2.679 months. In the analysis of oncologic safety, no patients died in AG and 1 patient died in CG. In addition, there was no significant difference between the two groups in terms of the overall recurrence rate and the distribution of recurrence types (P>0.05). As for satisfaction, the BREAST-Q score of AG was significantly higher than that of CG (57.85±4.833 vs 51.93±5.045, P<0.001). In the secondary outcomes, there was no short-term complication specified in the study; in the long-term complications, the incidence of calcification in AG was not significantly higher than that in CG (P=0.065). In the analysis of depression and anxiety, there was no significant difference between the two groups (P>0.05).

Conclusion

BCS combined with immediate AFG can significantly improve patients’ satisfaction without increasing the risk of death and tumor recurrence. However, it does not seem to play a role in improving the conditions of depression and anxiety.

Improved Vascularization and Survival of White Compared to Brown Adipose Tissue Grafts in the Dorsal Skinfold Chamber

Fat grafting is a frequently applied procedure in plastic surgery for volume reconstruction. Moreover, the transplantation of white adipose tissue (WAT) and brown adipose tissue (BAT) increasingly gains interest in preclinical research for the treatment of obesity-related metabolic defects. Therefore, we herein directly compared the vascularization capacity and survival of WAT and BAT grafts. For this purpose, size-matched grafts isolated from the inguinal WAT pad and the interscapular BAT depot of C57BL/6N donor mice were syngeneically transplanted into the dorsal skinfold chamber of recipient animals. The vascularization and survival of the grafts were analyzed by means of intravital fluorescence microscopy, histology, and immunohistochemistry over an observation period of 14 days. WAT grafts showed an identical microvascular architecture and functional microvessel density as native WAT. In contrast, BAT grafts developed an erratic microvasculature with a significantly lower functional microvessel density when compared to native BAT. Accordingly, they also contained a markedly lower number of CD31-positive microvessels, which was associated with a massive loss of perilipin-positive adipocytes. These findings indicate that in contrast to WAT grafts, BAT grafts exhibit an impaired vascularization capacity and survival, which may be due to their higher metabolic demand. Hence, future studies should focus on the establishment of strategies to improve the engraftment of transplanted BAT.

Oncologic safety of breast reconstruction with autologous fat grafting: A systematic review and meta-analysis

BACKGROUND

Autologous fat grating has become increasingly popular as a breast reconstructive procedure. Nevertheless, preclinical studies show that fat transfer to a previous breast cancer site could activate latent cancer cells, creating a favourable environment for disease recurrence. A systematic review and meta-analysis was performed to investigate whether fat grafting increases the risk of locoregional recurrence in patients formerly treated for breast cancer.

METHODS

Based on PRISMA guidelines, a systematic review searching for randomised clinical trials and matched cohorts on the topic was performed in the electronic databases Pubmed, Embase, Web of Science, and Cochrane. The date of the last search was July 20, 2021. The meta-analysis assessed the comparison of locoregional recurrence between groups.

RESULTS

From a total of 558 publications, data from nine matched cohorts (1.6%) reporting on 4247 subjects (1590 and 2657 subjects, respectively, in lipofilling and control groups) were suitable for inclusion in the meta-analysis. Neither of the outcomes had a statistically significant difference for disease recurrence. For the primary outcome, comparing locoregional recurrence rates between groups, the incidence rate ratio was 0.92 (95% CI: 0.68-1.26; P = 0.620).

CONCLUSION

The present meta-analysis, which comprises the outcomes of the individual studies with the best current evidence on the topic so far, strengthens the evidence favouring the oncologic safety of lipofilling for breast reconstruction.

A Role for Adipocytes and Adipose Stem Cells in the Breast Tumor Microenvironment and Regenerative Medicine

Obesity rates are climbing, representing a confounding and contributing factor to many disease states, including cancer. With respect to breast cancer, obesity plays a prominent role in the etiology of this disease, with certain subtypes such as triple-negative breast cancer having a strong correlation between obesity and poor outcomes. Therefore, it is critical to examine the obesity-related alterations to the normal stroma and the tumor microenvironment (TME). Adipocytes and adipose stem cells (ASCs) are major components of breast tissue stroma that have essential functions in both physiological and pathological states, including energy storage and metabolic homeostasis, physical support of breast epithelial cells, and directing inflammatory and wound healing responses through secreted factors. However, these processes can become dysregulated in both metabolic disorders, such as obesity and also in the context of breast cancer. Given the well-established obesity-neoplasia axis, it is critical to understand how interactions between different cell types in the tumor microenvironment, including adipocytes and ASCs, govern carcinogenesis, tumorigenesis, and ultimately metastasis. ASCs and adipocytes have multifactorial roles in cancer progression; however, due to the plastic nature of these cells, they also have a role in regenerative medicine, making them promising tools for tissue engineering. At the physiological level, the interactions between obesity and breast cancer have been examined; here, we will delineate the mechanisms that regulate ASCs and adipocytes in these different contexts through interactions between cancer cells, immune cells, and other cell types present in the tumor microenvironment. We will define the current state of understanding of how adipocytes and ASCs contribute to tumor progression through their role in the tumor microenvironment and how this is altered in the context of obesity. We will also introduce recent developments in utilizing adipocytes and ASCs in novel approaches to breast reconstruction and regenerative medicine.

Autologous fat grafting for breast reconstruction after breast cancer: a 12-year experience

Purpose

The aim of our study was to examine the surgical outcome and complications (efficiency) as well as the incidence of locoregional recurrence and distant metastases (oncological safety) in patients who underwent autologous fat grafting (AFG) of the breast following breast cancer surgery.

Methods

In our monocentric cohort study, retrospective and prospective data were collected from all consecutive patients who underwent AFG after breast cancer between 2008 and 2020; a total of 93 patients met the inclusion criteria.

Results

Our long-term results showed no increase in tumor recurrence and distant metastases in the studied collective when compared to the available literature. We observed 1 local recurrence (1.1%), 2 distant metastases (2.2%), and 1 tumor-related death (1.1%). There was a high degree of patient satisfaction; 67.12% of patients reported adequate satisfaction with autologous fat grafting.

Conclusion

Currently, to our knowledge, this is the study with the longest follow-up time (mean 6.7 years after AFG and 11.5 years after tumor resection). The results of our clinical study will contribute to improve evidence in the broad field of AFG, adipose stem cell and tumor research. Consistent with our study, the literature review shows a clear tendency of clinical trial results with a low incidence rate of tumor recurrence and metastasis following the use of AFG. AFG seems to be a safe procedure also after breast cancer treatment.

Autologous Fat Grafting for Oncologic Patients: A Literature Review

Autologous fat grafting (AFG) serves as an effective method to address volume defects, contour irregularities, and asymmetry in both aesthetic and reconstructive procedures. In recent years, there has been growing concern about the potential of cancer recurrence and interference with cancer surveillance in oncologic patients receiving AFG. The adipose tissue contains adipose-derived stem cells (ASCs), a specific type of mesenchymal stem cells, that facilitate secretion of numerous growth factors which in turn stimulate tissue regeneration and angiogenesis. As such, it has been theorized that ASCs may also have the potential to stimulate cancer cell proliferation and growth when used in oncologic patients. Multiple research studies have demonstrated the ability of ACSs to facilitate tumor proliferation in animal models. However, clinical research in oncologic patients has yielded contradictory findings. Although the literature pertaining to oncologic safety in head and neck, as well as sarcoma, cancer patients remains limited, studies demonstrate no increased risk of tumor recurrence in these patient populations receiving AFG. Similarly, both the efficacy and safety of AFG have been well established in breast cancer patients through numerous clinical studies. More recently, preclinical research in animal models has shown that AFG has the potential to facilitate tissue regeneration and improve joint contracture following irradiation. Ultimately, further research is needed to elucidate the safety of AFG in a variety of oncologic patients, as well as explore its use in tissue regeneration, particularly in the setting of radiotherapy. Level of Evidence: 4.

Oncologic Safety of Autologous Fat Grafting after Breast Cancer Surgical Treatment: A Matched Cohort Study

BACKGROUND

Autologous fat grafting has been an increasingly popular procedure for remodeling the breast of patients undergoing breast cancer surgery. This study's objective was to investigate whether autologous fat grafting is associated with a higher risk of disease recurrence in the context of late breast reconstruction for patients diagnosed with breast cancer who have undergone either breast-conserving surgery or mastectomy.

METHODS

A retrospective matched cohort study was performed in a single tertiary health care center. Data were collected from 42 patients formerly treated for breast cancer who underwent the first session of autologous fat grafting between August of 2007 and June of 2016. A total of 126 patients with similar features, who did not undergo autologous fat grafting, were individually matched at a 1:3 ratio with the autologous fat grafting group. The primary endpoint was locoregional recurrence. Secondary outcomes were rates of local and distant recurrences, disease-free survival, and overall survival.

RESULTS

At a mean follow-up of 65 months after fat grafting, no significant differences were found between the lipofilling and control groups for locoregional recurrence (7.1 percent versus 6.3 percent; p = 0.856), local recurrence (7.1 percent versus 5.6 percent; p = 0.705), distant recurrence (14.3 percent versus 7.9 percent; p = 0.238), disease-free survival (21.4 percent versus 19.0 percent; p = 0.837), and overall survival (14.3 percent versus 7.1 percent; p = 0.181).

CONCLUSIONS

No evidence of increased risk in any of the survival outcomes was identified. Lipofilling seems to be a safe procedure for breast reconstruction after surgical treatment of breast cancer.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Autologous Fat Grafting Does Not Increase Risk of Oncologic Recurrence in the Reconstructed Breast

INTRODUCTION

Autologous fat grafting (AFG) is a popular and effective method of breast reconstruction after mastectomy; however, the oncological safety of AFG remains in question. The aim of this study was to determine whether AFG increases the risk of cancer recurrence in the reconstructed breast.

METHODS

A matched, case-control study was conducted from 2000 to 2017 at the senior author's institution. Inclusion was limited to female patients who underwent mastectomy and breast reconstruction with or without AFG. Data were further subdivided at the breast level. χ analyses were used to test the association between AFG status and oncologic recurrence. A Cox proportional-hazards model was constructed to assess for possible differences in time to oncologic recurrence. The probability of recurrence was determined by Kaplan-Meier analyses and confirmed with log-rank testing.

RESULTS

Overall, 428 breasts met study criteria. Of those, 116 breasts (27.1%) received AFG, whereas 312 (72.9%) did not. No differences in the rates of oncologic recurrence were found between the groups (8.2% vs 9.0%, P < 1.000). Unadjusted (hazard ratio = 1.03, confidence interval = 0.41-2.60, P < 0.957) and adjusted hazard models showed no statistically significant increase in time to oncologic recurrence when comparing AFG to non-AFG. In addition, no statistical differences in disease-free survival were found (P = 0.96 by log rank test).

CONCLUSION

Autologous fat grafting for breast reconstruction is oncologically safe and does not increase the likelihood of oncologic recurrence. Larger studies (eg, meta analyses) with longer follow-up are needed to further elucidate the long-term safety of AFG as a reconstructive adjunct.

Oncological outcomes of lipofilling in breast reconstruction: a matched cohort study with 250 patients

Background

Fat grafting is a procedure commonly used in breast reconstruction nowadays. Nevertheless, its oncological safety remains controversial. The potential risk that progenitor cells included in fat graft tissue may contribute to disease progression in patients with breast cancer is still debatable. We have designed a matching-cohort study with 250 patients with history of breast cancer trying to elucidate an answer for this question.

Methods

We selected 250 patients with a history of breast cancer in our hospital, between 2011 and 2019. A total of 125 patients (cases) had a history of breast cancer reconstructed with fat grafting. The additional 125 patients are matched controls. We analyzed the distribution of eight different variables within the cases and their matched controls: date of first oncological surgery, age, type of oncological surgery, histological subtype, Her-2 status, pN, smoking habit and diabetes mellitus. The objective of this study was to analyze the influence of fat grafting over breast cancer recurrence.

Results

There are not statistically significant differences in breast cancer locoregional recurrences (P=0.183), distant metastases (P=0.200) or total recurrences (P=0.065) amongst the two groups (cancer cases and matched controls).

Conclusions

Our study adds more information over the oncological safety of fat grafting. These findings should encourage long-term prospective trials to provide surgeons with accurate information regarding the role of lipofilling on breast neoplasms.

Oncologic Safety of Autologous Fat Grafting in Breast Reconstruction

Autologous fat grafting is a useful adjunct to breast reconstruction to address contour changes, volume loss, and deformity. More recent benefits observed include mitigation of pain and inflammation. Although there is no clinical evidence to suggest an increased risk in recurrence or new cancer development in fat grafting for breast reconstruction, the oncologic safety of grafting has come into question. Adipose tissue grafts contain progenitor cells and immunomodulatory cytokines, which may induce vasculogenesis or tumor progression or recurrence at the site. Although these are all theoretical concerns, there is a discrepancy between basic science research and clinical outcomes studies. In this review, the authors summarize available literature regarding three important controversies in fat grafting for oncologic breast reconstruction: the interaction of graft component cells, such as adipose-derived stem cells, with cancer cells; the concern of fat grafting interference with breast cancer screening and detection; and clinical evidence regarding the oncologic safety of fat grafting following breast cancer treatment.

Adipose tissue-derived stem cells in breast reconstruction: a brief review on biology and translation

Recent developments in adipose-derived stromal/stem cell (ADSC) biology provide new hopes for tissue engineering and regeneration medicine. Due to their pluripotent activity, paracrine activity, and immunomodulatory function, ADSCs have been widely administrated and exhibited significant therapeutic effects in the treatment for autoimmune disorders, neurodegenerative diseases, and ischemic conditions both in animals and human clinical trials. Cell-assisted lipotransfer (CAL) based on ADSCs has emerged as a promising cell therapy technology and significantly improved the fat graft retention. Initially applied for cosmetic breast and facial enhancement, CAL has found a potential use for breast reconstruction in breast cancer patients. However, more challenges emerge related to CAL including lack of a standardized surgical procedure, the controversy in the effectiveness of CAL, and the potential oncogenic risk of ADSCs in cancer patients. In this review, we summarized the latest research and intended to give an outline involving the biological characteristics of ADSCs as well as the preclinical and clinical application of ADSCs.

Is Autologous Fat Grafting an Oncologically Safe Procedure following Breast Conserving Surgery for Breast Cancer? A Comprehensive Review

BACKGROUND

Autologous fat grafting (AFG) is a recognized surgical procedure to correct deformities following breast conservation surgery (BCS) for breast cancer. However, there are concerns about the oncological safety of this technique. In this study we have reviewed the current literature to assess whether AFG adversely influences the oncological outcome after BCS for breast cancer.

METHODS

We have searched the medical literature using the Embase and PubMed search engines from conception until May 2019 to identify all relevant studies of patients who underwent AFG after BCS. Meta-analysis and meta-regression methodologies were used to calculate the overall relative risk (RR) of loco-regional recurrence (LRR) rates for case-control and case series studies (with historical controls) respectively.

RESULTS

We have identified 26 eligible studies with a total of 1640 patients who had undergone fat transfer after lumpectomy for breast cancer. The meta-analysis of 11 studies revealed an overall RR for LRR of 0.82 [95% confidence interval (CI):0.14-1.66]. The meta-regression of case series revealed an overall incidence of LRR of 1.85% compared with 2.53% for historical controls.

CONCLUSIONS

Our study lends further support to the notion that fat transfer after lumpectomy for breast cancer does not seem to increase the risk of LRR. However further prospective research is required in order to confirm this.

Effects of Prophylactic Lipofilling After Radiotherapy Compared to Non-Fat Injected Breasts: A Randomized, Objective Study

BACKGROUND

Patients who are suffering from invasive breast cancer may require post-mastectomy radiation therapy (PMRT). PMRT improves outcomes in breast cancer patients in terms of locoregional recurrence. Preliminary studies indicate that fat injections reduce post-radiation damage of soft tissue and implants.

OBJECTIVES

The aim of this study was to demonstrate the safety and effectiveness of prophylactic fat injections on radiated implanted breasts.

METHODS

The authors randomly assigned 60 female patients to either Group A or B. Group A patients received 3 breast fat injections, according to Coleman's technique, after radiotherapy and before expander removal with definitive implant insertion. Group B patients underwent surgery without lipofilling. At each surgical operation, skin biopsies were performed in a specific breast area to evaluate adipose tissue thickness, and a statistical analysis of the thickness variations was performed with the Wilcoxon's sum test. Disability was assessed according to the Late Effects of Normal Tissues-Subjective Objective Management Analytic scale.

RESULTS

The study demonstrates a qualitative and quantitative improvement about tissues after fat injection. This is highlighted by the significant increase in thickness after lipofilling.

CONCLUSIONS

The study, which is based on both clinical and histological findings and is supported by the comparison of a control group with a 1-year follow-up, demonstrates that fat injections reduce tissue radio damage, improving reconstructive surgery outcomes and quality of life.

LEVEL OF EVIDENCE: 2

Oncologic Safety and Surveillance of Autologous Fat Grafting following Breast Conservation Therapy

BACKGROUND

Autologous fat grafting is a useful adjunct following breast reconstruction. The impact of autologous fat grafting on oncologic safety and surveillance remains questionable, particularly following breast conservation therapy.

METHODS

The authors performed a retrospective review of patients who underwent delayed fat grafting following breast conservation therapy between 2006 and 2016. A control group of conservatively managed patients without grafting was matched for cancer stage, age, body mass index, and follow-up. Outcomes included locoregional recurrence and oncologic surveillance.

RESULTS

Seventy-two patients were identified per cohort. There were no differences in median age (50 years versus 51 years; p = 0.87), body mass index (28.2 kg/m versus 27.2 kg/m; p = 0.38), or length of follow-up (61.9 months versus 66.8 months; p = 0.144) between controls and grafted patients, respectively. Overall, four patients in each cohort experienced recurrence (5.6 percent; p = 1.00) with similar cumulative incidence estimates observed (log-rank test, p = 0.534). There were no significant differences in palpable mass (9.7 percent versus 19.4 percent; p = 0.1), fat necrosis (34.7 percent versus 33.3 percent; p = 0.86), calcifications (37.5 percent versus 34.7 percent; p = 0.73), or indication for breast biopsy (15.3 percent versus 22.2 percent; p = 0.23) between breast conservation and breast conservation therapy plus autologous fat grafting cohorts, respectively.

CONCLUSIONS

Overall, the authors found no difference in recurrence rates after breast conservation with or without delayed fat grafting. Furthermore, there were no differences in the rates of fat necrosis, palpable mass, and abnormal radiographic findings. This study represents the longest follow-up to date in in a large matched study of autologous fat grafting with breast conservation therapy demonstrating oncologic safety and no interference with follow-up surveillance.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Extensive Characterization of Mesenchymal Stem Cell Marker Expression on Freshly Isolated and In Vitro Expanded Human Adipose-Derived Stem Cells from Breast Cancer Patients

Variation in numbers and functions of cells in fat tissues may affect therapeutic outcomes and adverse events after autologous fat tissue grafting in postmastectomy breast cancer patients; however, the relevant information regarding cellular components is still incomplete. Phenotypic characterization of heterogeneous cell subsets in stromal vascular fraction (SVF) isolated from fat tissues by flow cytometry was also limited to a combination of few molecules. This study, therefore, developed a polychromatic staining panel for an in-depth characterization of freshly isolated SVF and expanded adipose-derived stem cells (ADSC) from the patients. ADSC were found predominant in SVF (~65% of CD45⁻ cells) with a homogenous phenotype of CD13⁺CD31⁻CD34⁺CD45⁻CD73⁺CD90⁺CD105⁻CD146⁻ (~94% of total ADSC). Endothelial progenitor cells (EPC) and pericytes were minor (~18% and ~11% of CD45⁻ cells, respectively) with large heterogeneity. Downregulation of CD34 and upregulation of CD105 in ADSC were profound at passage 3, showing a phenotype similar to the classical mesenchymal stem cells from the bone marrow. Results from this study demonstrated that fat tissue collected from patients contains ADSC with a highly homogenous phenotype. The in vitro culture of these cells maintained their homogeneity with modified CD34 and CD105 expression, suggesting the expansion from a single population of ADSC.

Long-term Follow-up of Autologous Fat Transfer vs Conventional Breast Reconstruction and Association With Cancer Relapse in Patients With Breast Cancer

Importance

Autologous fat transfer (AFT or fat grafting) has become an invaluable tool for the correction of disfiguring deformities after breast cancer surgery. However, clinical and animal studies have shown conflicting results regarding its oncologic safety.

Objective

To determine whether exposure to AFT vs conventional breast reconstruction is associated with increased rates of cancer relapse in patients with breast cancer.

Design, Setting, and Participants

This matched cohort study involved retrospective medical record review to identify all patients in a local patient database receiving AFT between 2006 and 2014. Each AFT case was matched with a nonexposed control patient with similar baseline characteristics. The mean (SD) follow-up of patients receiving AFT was 9.3 (4.9) years including 5.0 (1.7) years following AFT. Control patients were followed up for a mean (SD) of 8.6 (1.8) years from the primary surgery. Patients were identified through the local patient database of the Tergooi Hospital in Hilversum, the Netherlands. A total of 287 patients with breast cancer (300 affected breasts) who received AFT for breast reconstruction after cancer were included in the intervention group. Each AFT case was matched with a respective control patient based on age, type of oncologic surgery, tumor invasiveness, and disease stage. In addition, individual AFT-control pairs were selected to have the same locoregional recurrence-free interval at baseline. Data were analyzed between 2016 and 2017.

Exposures

Reconstruction with AFT vs conventional breast reconstruction or none.

Main Outcomes and Measures

Primary end points were the cumulative incidences of oncologic events in AFT and control patients and their respective hazard ratios.

Results

Of the 587 total patients, all were women and the mean age was 48.1 years for the patients undergoing AFT and 49.4 years for the control patients. Eight locoregional recurrences were observed in the treatment group (287 patients) and 11 among the control group (300 patients), leading to an unadjusted hazard ratio of 0.63 (95% CI, 0.25-1.60; P = .33). No increased locoregional recurrence rates were seen in relevant subgroups based on the type of oncological surgery, tumor invasiveness, or pathological stage. In addition, no increased risks with AFT were detected with respect to distant recurrences or breast cancer-specific mortality.

Conclusions and Relevance

No significant differences in the locoregional recurrence rates between the AFT and control groups were observed after 5 years of follow-up. These findings confirm the results of previous studies; therefore, clinical evidence suggesting that AFT is associated with increased risk for cancer relapse is still lacking.

The use of autologous fat grafts in breast surgery: A literature review

Autologous fat injection was first described roughly a century ago and has been used in surgery ever since. In addition to its use in many surgical fields, it is also frequently used for both aesthetic and reconstructive purposes in breast surgery. Since the application of fat grafting in breast surgery has steadily increased, studies investigating its reliability have simultaneously become increasingly common. Previous studies have reported that the use of fat grafting in breast surgery is reliable, but some pending questions remain about its routine use. In order to use fat grafts successfully in breast surgery, it is necessary to be familiar with the structure and content of adipose tissue, the efficacy of adipose stem cell-enriched fat grafts, the oncological safety of fat grafts, and the problems that may occur in the radiological follow-up of patients who undergo fat grafting procedures. In this literature review, we aim to discuss the use of fat grafts in breast surgery by investigating these common problems.

Epinephrine Infiltration of Adipose Tissue Impacts MCF7 Breast Cancer Cells and Total Lipid Content

BACKGROUND

Considering the positive or negative potential effects of adipocytes, depending on their lipid composition, on breast tumor progression, it is important to evaluate whether adipose tissue (AT) harvesting procedures, including epinephrine infiltration, may influence breast cancer progression.

METHODS

Culture medium conditioned with epinephrine-infiltrated adipose tissue was tested on human Michigan Cancer Foundation-7 (MCF7) breast cancer cells, cultured in monolayer or in oncospheres. Lipid composition was evaluated depending on epinephrine-infiltration for five patients. Epinephrine-infiltrated adipose tissue (EI-AT) or corresponding conditioned medium (EI-CM) were injected into orthotopic breast carcinoma induced in athymic mouse.

RESULTS

EI-CM significantly increased the proliferation rate of MCF7 cells Moreover EI-CM induced an output of the quiescent state of MCF7 cells, but it could be either an activator or inhibitor of the epithelial mesenchymal transition as indicated by gene expression changes. EI-CM presented a significantly higher lipid total weight compared with the conditioned medium obtained from non-infiltrated-AT of paired-patients. In vivo, neither the EI-CM or EI-AT injection significantly promoted MCF7-induced tumor growth.

CONCLUSIONS

Even though conditioned media are widely used to mimic the secretome of cells or tissues, they may produce different effects on tumor progression, which may explain some of the discrepancy observed between in vitro, preclinical and clinical data using AT samples.

Does Choice of Reconstruction Type Affect Survival in Patients With Metastatic Breast Cancer?

BACKGROUND

To compare the breast cancer-specific survival (BCSS) and overall survival (OS) between patients who underwent implant or tissue reconstruction after mastectomy with distant metastatic breast cancer (MBC).

MATERIALS AND METHODS

Using the Surveillance, Epidemiology, and End Results database, we enrolled 371 female MBC cases diagnosed during the years 2004-2014. Patients were subdivided into implant (176) and tissue groups (195) for survival comparison between the two groups. The end points were BCSS and OS. Comparisons of the distribution of clinicopathologic characteristics were evaluated by chi-square test and Fisher exact test. Survival outcomes were compared by Kaplan-Meier model and multivariate Cox regression model for known clinicopathologic variables in both the entire population and in the reconstruction cohorts.

RESULTS

In the entire cohort, patients with implant exhibited distinctly better BCSS (log rank, P = 0.002) and OS (log rank, P = 0.001) than patients with tissue reconstruction. Multivariate Cox regression model revealed that patients, who received prosthetic implants, were married, and progesterone receptor-positive group showed better survival rates in BCSS and OS. In addition, after stratification of the implant group and tissue groups according to clinicopathologic variables, the survival rate of patients in the implant group was higher than that in the tissue reconstruction group under the influence of factors, such as married, estrogen receptor-negative, nonradiotherapy, and chemotherapy.

CONCLUSIONS

Our study provides further survival evidence supporting the practice of mastectomy with prosthetic implant reconstruction in patients with MBC under certain conditions.

International Expert Panel Consensus on Fat Grafting of the Breast

Background

Autologous fat grafting has broad applications in reconstructive and aesthetic breast surgery as a natural filler and for its regenerative purposes. Despite the widespread use of fat grafting, there remains no shared consensus on what constitutes the optimal fat grafting technique and its oncological safety. For this reason, the authors of this study have organized a Survey and an International Consensus Conference that was held at the Aesthetic Breast Meeting in Milan (December 15, 2018).

Methods

All studies on fat grafting, both for breast aesthetic and reconstructive purposes, were electronically screened. The literature review led to 17 "key questions" that were used for the Survey. The authors prepared a set of 10 "key statements" that have been discussed in a dedicated face-to-face session during the meeting.

Results

The 10 key statements addressed all the most debated topics on fat grafting of the breast. Levels of evidence for the key statements ranged from III to IV with 2 statements (20%) supported by a level of evidence III and 6 statements (60%) by level of evidence IV. Overall consensus was reached for 2 statements (20%) with >75% agreement reached for 7 statements.

Conclusions

The survey demonstrated a diversity of opinion and attitude among the panelists with regard to technique. Clear recommendations for evidence-based clinical practice for fat grafting use both in aesthetic and reconstructive breast surgery could not be defined due to the scarcity of level 1 or 2 studies.

Autogenous Fat Grafting to the Breast and Gluteal Regions: Safety Profile Including Risks and Complications

Given the widespread utility and therapeutic potential of autogenous fat grafting, plastic surgeons should be familiar with its safety profile and associated adverse events. This article provides a critical review of the literature and delineates risk factors associated with various complications when grafting to the breast and gluteal regions. The majority of adverse events are related to fat necrosis and require minimal diagnostic or therapeutic intervention. Larger graft volumes, as in cosmetic augmentation, are associated with higher incidences of fatty necrosis. The oncologic safety of fat grafting is supported by multiple clinical studies with thousands of breast cancer patients, albeit predominantly retrospective in nature. Although less frequent, serious complications include fat emboli during gluteal augmentation. Identification of associated risk factors and implementation of proper surgical techniques may minimize the occurrence of life-threatening complications.

Autologous fat transfer after breast cancer surgery: An exact-matching study on the long-term oncological safety

INTRODUCTION

Autologous fat transfer (AFT) is widely adopted for breast reconstruction, but its long-term oncologic safety is still not clearly established. The aim of the present study was to compare the 10-year loco-regional recurrence (LRR)-free and distant metastases (DM)-free survival probabilities in AFT vs. control patients, also evaluating the impact of AFT in different intrinsic molecular subtypes of breast cancer.

MATERIALS AND METHODS

464 AFT patients were exactly matched with a cohort of 3100 control patients treated between 2007 and 2017. A multivariate survival analysis was performed accounting for all variables related to LRR and DM, including adjuvant/neoadjuvant treatments. End-points were analyzed both overall and in each molecular subtype.

RESULTS

LRR occurred in 6.4% of AFT and in 5.0% of control patients (p = 0.42), while DM were observed respectively in 7.7% and 5.4% of cases (p = 0.20). AFT showed no effect on the 10-year LRR-free survival probability (adjusted HR 0.87, 95%CI 0.43-1.76, p = 0.69) or the 10-year DM-free survival probability (adjusted HR 0.82, 95%CI 0.43-1.57, p = 0.55). Luminal A patients treated by AFT showed a decreased LRR-free survival probability (HR 2.38, 95%CI 0.91-6.17, Log-Rank p = 0.07), which was significantly lower than controls after 80 months (Log-Rank p = 0.02). No differences in the 10-year event-free survival probability were found in Luminal B, HER2-positive or triple-negative patients.

CONCLUSION

AFT does not increase breast cancer recurrence, with the possible exception of late LRRs for Luminal A patients, but further clinical and preclinical data are required to better clarify this data. The use of AFT should not be discouraged.

Lipofilling after breast conserving surgery: a comprehensive literature review investigating its oncologic safety

Lipofilling has regenerative properties used to improve deformities after breast conserving surgery. Our hypothesis is that there is inadequate data to ensure that lipofilling does not increase locoregional cancer recurrence after breast conserving surgery. A PRISMA comprehensive literature review was conducted of articles published prior to October 2019 investigating recurrence in patients who underwent lipofilling after breast conserving surgery. All forms of breast conserving surgery, fat grafting, and injection intervals were included. Patients undergoing mastectomy were excluded. Requirements to define lipofilling as "safe" included (I) a defined interval between resection and lipofilling; (II) a minimum follow-up period of 6 years from tumor resection; (III) a minimum follow-up period of 3 years from lipofilling; (IV) presence of a control group; (V) controls matched for ER/PR/Her-2; (VI) a sub-group analysis focusing on ER/PR/Her-2; (VII) adequate powering. Nineteen studies met inclusion criteria. The range in time from breast conserving surgery to fat injection was 0-76 months. The average time to follow-up after lipofilling was 23 days-60 months. Two studies had a sufficient follow-up time from both primary resection and from lipofilling. Seventeen of the nineteen studies specified the interval between resection and lipofilling, but there is currently no consensus regarding how soon lipofilling can be performed following BCS. Eight studies performed a subgroup analysis in cases of recurrence and found recurrence after lipofilling was associated with number of positive axillary nodes, intraepithelial neoplasia, high grade histology, Luminal A subtype, age <50, Ki-67 expression, and lipofilling within 3 months of primary resection. Of the eleven studies that included a comparison group, one matched patient for Her-2 and there was a statistically significant difference in Her-2 positive cancers in the study arms of two articles. Several studies deemed lipofilling "safe," two showed association of lipofilling and local recurrence, and most studies concluded that further research was needed. Insufficient and contradictory data exists to demonstrate the safety of lipofilling after breast conserving surgery. A multicentered, well designed study is needed to verify the safety of this practice.

An Animal Model of Local Breast Cancer Recurrence in the Setting of Autologous Fat Grafting for Breast Reconstruction

Autologous fat grafting after breast cancer surgery is commonly performed, but concerns about oncologic risk remain. To model the interaction between fat grafting and breast cancer cells, two approaches were employed. In the first approach, graded numbers of viable MDA‐MB‐231 or BT‐474 cells were admixed directly into human fat grafts and injected subcutaneously into immune‐deficient mice to determine if the healing graft is a supportive environment for the tumor. In the second approach, graded doses of MDA‐MB‐231 cells were suspended in Matrigel and injected into the mammary fat pads of mice. Two weeks after the tumor cells engrafted, 100 μL of human adipose tissue was grafted into the same site. Histologically, MDA‐MB‐231 cells seeded within fat grafts were observed and stained positive for human‐specific pan‐cytokeratin and Ki67. The BT‐474 cells failed to survive when seeded within fat grafts at any dose. In the second approach, MDA‐MB‐231 cells had a strong trend toward lower Ki67 staining at all doses. Regression analysis on all groups with fat grafts and MDA‐MB‐231 revealed fat tissue was associated with lower cancer cell Ki67 staining. Healing fat grafts do not support the epithelial BT‐474 cell growth, and support the mesenchymal MDA‐MB‐231 cell growth only at doses ten times greater than in Matrigel controls. Moreover, fat grafts in association with MDA‐MB‐231 cancer cells already present in the wound resulted in decreased tumor proliferation and increased fibrosis. These findings suggest that clinical fat grafting does not induce breast cancer cell growth, and may even have a suppressive effect. stemcellstranslationalmedicine2018;7:125–134

Oncological Risk in Autologous Stem Cell Donation for Novel Tissue-Engineering Approaches to Postmastectomy Breast Regeneration

Adipose tissue engineering using adipose-derived stem cells (ADSCs) has emerged as an opportunity to develop novel approaches to postmastectomy breast reconstruction with the potential for an autologous tissue source with a natural appearance and texture. As of yet, the role of ADSCs in breast cancer development and metastasis is not completely understood; therefore, we must consider the oncological safety of employing an autologous source of ADSCs for use in breast regeneration. This study investigated the regenerative properties of ADSCs isolated from breast cancer patients, including those who had received neoadjuvant chemotherapy, and noncancer controls. The ADSCs were characterised for several parameters central to tissue regeneration, including cell viability, proliferation, differentiation potential, and cytokine secretion. A stem cell population was isolated and confirmed by flow cytometry and multilineage differentiation. There was no difference in cell phenotype or surface antigen expression between ADSCs from different sources. Adipose-derived stem cells isolated from the breast of cancer patients exhibited reduced adipogenic differentiation potential compared with ADSCs from other sources. The greatest degree of adipogenic differentiation was observed in ADSCs isolated from the subcutaneous abdominal fat of noncancer controls. The proliferation rate of ADSCs isolated from the breast of cancer patients was increased compared with other sources; however, it was decreased in ADSCs isolated from breast cancer patients who had recently been treated with neoadjuvant chemotherapy. A number of cytokines were detected in the cell conditioned media of ADSCs from different sources, including matrix metalloproteinase-2 (MMP-2), which was detected at higher levels in the secretome of ADSCs from breast cancer patients compared with noncancer controls. This study provides important information relating to the suitability of ADSCs as an autologous cell source for adipose tissue engineering in postcancer reconstruction. Results indicate that while the surface phenotype does not differ, the differentiation capacity, proliferative rate, and secreted cytokine profile are affected by the presence or treatment of breast cancer. These findings support further investigation into the regenerative potential of these ADSCs, if they are to be considered in clinical reconstructive strategies.

Does lipofilling after oncologic breast surgery increase the amount of suspicious imaging and required biopsies?-A systematic meta-analysis

OBJECTIVE

The aim of our systematic meta-analysis was to find out if lipofilling to the breast alters follow-up imaging procedures and leads to an increased number of biopsies because of suspicious findings.

METHODS

We conducted a systematic meta-analysis of the literature including all prospective and retrospective studies focusing on imaging outcomes in patients with a history of breast cancer who have received one or more lipofilling procedures after oncologic surgery to the breast.

RESULTS

Twelve studies met the inclusion criteria, comprising 1711 patients and at least 2261 lipofilling procedures. 564 patients (33%) were followed up only with ultrasound, 735 patients (43%) only received mammography, 273 (16%) had a combination of ultrasound, mammography and MRI, and 37 patients (2.1%) were followed up via ultrasound and mammography. A collective of 102 patients making up a matched-cohort study received ultrasound, mammography, MRI, and PET/CT, while only 51 of them made up the investigation group who had autologous fat grafting (3%). Biopsy rates were 1%-24% with a medium of 6.5% over all groups. Medium follow-up was 18.8 months (range 6-50 months). The rate of local oncologic events among the patients with lipofilling procedures detected during the study periods was 0.7%.

CONCLUSION

Lipofilling to the breast after oncologic operations appears to be a safe procedure with overall low biopsy and local recurrence rate. Suspicious imaging occurs in most cases out of physiologic remodeling and inflammation processes at the operation site and needs to be distinguished from malignant focusses. The amount of required biopsies stands in relation to the used imaging method and the time to follow-up.

Autologous Lipotransfer - Daily Therapeutic Practice in Breast Cancer: An Intergroup Analysis Encompassing NOGGO, WSG, GBG, AWO Gyn and DGPRÄC

Background

Autologous fat transfer in breast reconstruction has become increasingly important in breast reconstructive surgery. Although the indication to obtain fat, the various operative procedures, and the risks for the patient have been addressed in a large number of studies, detailed information on the everyday use of autologous lipotransfer in breast units in Germany is still lacking.

Methods

The objective of the study was to obtain primary data on the use of autologous lipotransfer to treat breast cancer patients in Germany and to determine measures for quality assurance in the daily practice. An online questionnaire concerning breast cancer and lipofilling was sent to specialists in gynecology and plastic surgery.

Results

Two-thirds of the specialists who responded to the questionnaire use autologous lipotransfer for breast reconstruction and did not report an increase of local recurrence following lipotransfer. There were only small differences between gynecologists and plastic surgeons regarding the procedure and indication for lipotransfer. The method is highly accepted by patients and physicians, and both gynecologists and plastic surgeons rated the improvement achieved through lipofilling as 'high'.

Conclusions

The lack of randomized controlled data, especially in high-risk patients, demonstrates the necessity for a registry study on this topic. Our survey describes, in detail, the indications for lipofilling as well as its appropriate application in breast cancer patients in Germany and may thereby reduce the present therapeutic uncertainties.

Adipose-Derived Stem Cells in Cancer Progression: New Perspectives and Opportunities

Growing importance has been attributed to interactions between tumors, the stromal microenvironment and adult mesenchymal stem cells. Adipose-derived stem cells (ASCs) are routinely employed in regenerative medicine and in autologous fat transfer procedures. To date, clinical trials have failed to demonstrate the potential pro-oncogenic role of ASC enrichment. Nevertheless, some pre-clinical studies from in vitro and in vivo models have suggested that ASCs act as a potential tumor promoter for different cancer cell types, and support tumor progression and invasiveness through the activation of several intracellular signals. Interaction with the tumor microenvironment and extracellular matrix remodeling, the exosomal release of pro-oncogenic factors as well as the induction of epithelial-mesenchymal transitions are the most investigated mechanisms. Moreover, ASCs have also demonstrated an elective tumor homing capacity and this tumor-targeting capacity makes them a suitable carrier for anti-cancer drug delivery. New genetic and applied nanotechnologies may help to design promising anti-cancer cell-based approaches through the release of loaded intracellular nanoparticles. These new anti-cancer therapies can more effectively target tumor cells, reaching higher local concentrations even in pharmacological sanctuaries, and thus minimizing systemic adverse drug effects. The potential interplay between ASCs and tumors and potential ASCs-based therapeutic approaches are discussed.