Fat grafting for breast cancer patients: From basic science to clinical studies

Adipose-derived stem cells enhance the tumorigenic potential of pre-malignant breast epithelial cells through paracrine activation of PI3K-AKT pathway

BACKGROUND

Adipose-derived stem cells (ADSCs)-assisted fat grafting has emerged as a widely used procedure for breast reconstruction post mastectomy and for aesthetic augmentation. Given the limited cases of breast cancer following grafting, the oncological safety of this procedure remains controversial.

METHODS

The effects of ADSCs on the oncogenic features of premalignant MCF-10AT cells were investigated using co-culture and xenograft models. We further evaluated the malignancy-promoting effect of ADSCs in a 7,12-Dimethylbenz(a)anthracene (DMBA)-induced breast cancer model. RNA-sequencing was performed on ADSCs, MCF-10AT cells, and ADSC-co-cultured MCF-10AT cells. Protein changes in ADSC/MCF-10AT co-culture medium and MCF-10AT cells were determined by proteomic analysis. Pathway inhibitors were used to investigate signaling pathways involved in the ADSC-induced oncogenic changes of MCF-10AT cells.

RESULTS

We found that ADSCs promoted the proliferation and migration of MCF-10AT cells, and co-injection of ADSCs increased the tumor incidence of MCF-10AT cells from 29% to 58% in nude mice. Additionally, grafted ADSCs significantly enhanced tumor incidence, growth, and distant metastasis in the DMBA-induced rats, while it could not induce tumorigenesis in normal breast tissues. Combined RNA-sequencing and proteomic analysis demonstrated that the paracrine factors secreted by ADSCs robustly activated the oncogenic PI3K-AKT signaling in MCF-10AT cells. We also revealed the auto-activated TGF-beta and Wnt pathways in co-cultured MCF-10AT cells, which may be synergistic in tumor formation and progression. As expected, blocking these pathways, especially the PI3K-AKT pathway, strongly diminished the promoting effects of ADSCs, suggesting their potential as therapeutic targets for ADSC grafting-associated breast tumors.

CONCLUSIONS

Our data illustrated the synergistic effect between ADSC paracrine factors and MCF-10AT auto-activated pathways in the carcinogenesis of MCF-10AT cells through activation of the oncogenic PI3K-AKT pathway. Based on these findings, we strongly recommend pre-operative examinations for breast cancer risk factors before ADSC-associated transplantation.

Proliferation Patterns of MCF-7 Breast Cancer Cells in Lipoaspirate Conditioned Media

INTRODUCTION

Autologous fat grafting (AFG) is a common technique used to enhance aesthetic outcomes in postmastectomy breast reconstruction patients. Adipokines are hormones secreted by adipose tissue that play a critical role in regulating metabolic processes and the immune system. However, dysregulated adipokine secretion and signaling can contribute to the development and progression of cancer by promoting angiogenesis, altering the immune response, and inducing the epithelial mesenchymal transition. We aimed to assess how breast cancer cells behave in conditioned media derived from fat grafting lipoaspirates and gain a better understanding of the potential interactions that may occur within the tumor microenvironment.

METHODS

Patients who were undergoing AFG as a part of breast reconstruction at NY-Presbyterian/Weill Cornell Medical Center between March 2021 and July 2023 were consented and enrolled in the study. This study was approved by the Weill Cornell Medicine Institutional Review Board (#20-10022850-14). Conditioned media is created using 20% of patient lipoaspirate secretome and 80% starving media. The growth of MCF-7, a human ER/PR+ breast cancer cell line, in conditioned media is assessed using CyQUANT.

RESULTS

The breast cancer cells incubated in conditioned media displayed similar growth trends as those in complete media, which is enriched for cell growth (P > 0.05). MCF-7 cell behavior in conditioned media differed significantly from their proliferation patterns when serum starved in 100% starving media (P < 0.05).

DISCUSSION

Our results suggest that there may be inherent factors within the lipoaspirate that may promote MCF-7 proliferation. One potential implication is that AFG used for breast reconstruction should be delayed until local-regional disease control has been established. In addition, based on the in vitro proliferation patterns of breast cancer cells in conditioned media, the safety profile of AFG may be enhanced if the procedure is performed after attaining negative margins and the completion breast cancer treatment.

[Lipofilling in the management of breast cancer: An update based on a literature review and national and international guidelines]

BACKGROUND

Lipomodelling (LM) is an increasingly used technique to reconstruct or correct an aesthetic defect linked to a loss of substance. In France, the Haute Autorité de santé (HAS) published recommendations in 2015 and 2020 concerning the conditions of use of LM on the treated and contralateral breast. These appear to be inconsistently followed.

METHODS

Twelve members of the Senology Commission of the Collège national des gynécologues-obstétriciens français (French College of Gynecologists and Obstetricians) reviewed the carcinological safety of LM and the clinical and radiological follow-up of patients after breast cancer surgery, based on French and international recommendations and a review of the literature. The bibliographic search was conducted via Medline from 2015 to 2022, selecting articles in French and English and applying PRISMA guidelines.

RESULTS

A total of 14 studies on the oncological safety of LM, 5 studies on follow-up and 7 guidelines were retained. The 14 studies (6 retrospective, 2 prospective and 6 meta-analyses) had heterogeneous inclusion criteria and variable follow-up, ranging from 38 to 120 months. Most have shown no increased risk of locoregional or distant recurrence after LM. A retrospective case-control study (464 LMs and 3100 controls) showed, in patients who had no recurrence at 80 months, a subsequent reduction in recurrence-free survival after LM in cases of luminal A cancer, highlighting the number of lost to follow-up (more than 2/3 of luminal A cancers). About follow-up after LM, the 5 series showed the high frequency after LM of clinical mass and radiological images (in ¼ of cases), most often corresponding to cytosteatonecrosis. Most of the guidelines highlighted the uncertainties concerning oncological safety of LM, due to the lack of prospective data and long-term follow-up.

DISCUSSION AND PERSPECTIVES

The members of the Senology Commission agree with the conclusions of the HAS working group, in particular by advising against LM "without cautionary periods", excessively, or in cases of high risk of relapse, and recommend clear, detailed information to patients before undergoing LM, and the need for postoperative follow-up. The creation of a national registry could address most questions regarding both the oncological safety of this procedure and the modalities of patient follow-up.

Oncologic Safety in Autologous Fat Grafting After Breast Conservation Therapy: A Systematic Review and Meta-analysis of the Literature

BACKGROUND

Autologous fat grafting (AFG) is often used to reconstruct defects after breast conservation therapy (BCT). However, concerns exist about the possibility of AFG-related recurrence or metastasis. This study aims to evaluate the literature to evaluate oncologic outcomes in patients undergoing AFG at the time of BCT.

METHODS

A systematic review of articles related to AFG based reconstruction at the time of BCT from 1970 to 2021 was performed via PubMed. Patients were grouped based on the presence or lack of AFG usage at the time of BCT, and oncologic outcomes and complications were compared.

RESULTS

Of the 146 articles identified, 15 were included. Nine hundred patients underwent BCT alone and 1063 patients underwent BCT with AFG patients. Similar average follow-up time was observed between the groups, 58.7 months (BCT only) and 55.2 months (BCT with AFG). On pooled analysis, no difference was identified in local recurrence 4.8% (43 patients) of the BCT group and 3% (32 patients) in the AFG group (P = 0.8), metastasis 4.8% (43 patients) of the BCT group and 6.9% (73 patients) in the AFG group (P = 0.3), or fat necrosis (P = 0.44). Meta-analysis additionally did not identify any statistically significant odds ratios between the BCT only group and BCT with AFG group when evaluated for total recurrence, local recurrence, metastasis or fat necrosis.

CONCLUSIONS

The results show no significant difference in cancer recurrence or metastasis in the BCT only group versus BCT and AFG, showing that fat grafting has safe outcomes.

Application of Fat Grafting in Cosmetic Breast Surgery

The role of fat grafting to the breasts has evolved in the recent past, gaining several new applications within both reconstructive and aesthetic surgery. Initially used for reconstructive purposes to fill lumpectomy defects or to correct residual contour deformities after breast reconstruction, it has since made its way into cosmetic breast surgery and has grown to encompass a wide variety of new indications. Fat grafting in aesthetic breast surgery may be performed as a form of primary autologous breast augmentation or as an adjunct to implant-based breast augmentation to disguise implant edges. It may also be used to provide added volume after explant surgery or to provide improvements in breast contour alongside mastopexy techniques. In this article, we will review the current applications of fat grafting in aesthetic breast surgery and provide an up-to-date summary of its reported outcomes, safety, and complications.

Oncological Safety of Lipofilling in Healthy BRCA Carriers After Bilateral Prophylactic Mastectomy: A Case Series

OBJECTIVE

The germline breast cancer gene (BRCA) mutation confers a lifetime high risk for breast cancer (BC) and bilateral prophylactic mastectomy is the procedure which allows the highest risk reduction rate. Among other techniques, lipofilling (LF) can be used for breast reconstruction of these patients. However, there are some oncological safety concerns on the subject. The purpose of this study was to assess the oncological risk of LF in BRCA healthy patients.

MATERIALS AND METHODS

A single institution case series was built including BRCA I/II mutated patients with no previous history of BC, who underwent bilateral prophylactic mastectomy followed by breast reconstruction with exclusive LF or combined with implants or latissimus dorsi flap. Data were collected regarding patient demographics, clinical information, reconstruction techniques used, and fat grafting details.

RESULTS

From September 1999 till November 2017, we identified 18 BRCA carriers with no history of BC who had undergone bilateral prophylactic mastectomy, followed by breast reconstruction with LF. A total of 36 LF procedures were performed following an implant or latissimus dorsi flap, or as an exclusive fat grafting breast reconstruction. The average number of LF sessions was 1.4 with a mean volume of 108.8cc per breast. Median follow-up was 33.0 months after mastectomy and 24.5 months after the last LF intervention; no patients were diagnosed with BC during follow-up.

CONCLUSION

Germline BRCA mutation is a high-risk plight for BC. However, despite the limited follow-up, no BC was detected.

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.

Oncoplastic Breast Consortium consensus conference on nipple-sparing mastectomy

Purpose

Indications for nipple-sparing mastectomy (NSM) have broadened to include the risk reducing setting and locally advanced tumors, which resulted in a dramatic increase in the use of NSM. The Oncoplastic Breast Consortium consensus conference on NSM and immediate reconstruction was held to address a variety of questions in clinical practice and research based on published evidence and expert panel opinion.

Methods

The panel consisted of 44 breast surgeons from 14 countries across four continents with a background in gynecology, general or reconstructive surgery and a practice dedicated to breast cancer, as well as a patient advocate. Panelists presented evidence summaries relating to each topic for debate during the in-person consensus conference. The iterative process in question development, voting, and wording of the recommendations followed the modified Delphi methodology.

Results

Consensus recommendations were reached in 35, majority recommendations in 24, and no recommendations in the remaining 12 questions. The panel acknowledged the need for standardization of various aspects of NSM and immediate reconstruction. It endorsed several oncological contraindications to the preservation of the skin and nipple. Furthermore, it recommended inclusion of patients in prospective registries and routine assessment of patient-reported outcomes. Considerable heterogeneity in breast reconstruction practice became obvious during the conference.

Conclusions

In case of conflicting or missing evidence to guide treatment, the consensus conference revealed substantial disagreement in expert panel opinion, which, among others, supports the need for a randomized trial to evaluate the safest and most efficacious reconstruction techniques.

Electronic supplementary material

The online version of this article (10.1007/s10549-018-4937-1) contains supplementary material, which is available to authorized users.

Meta-analysis of the oncological safety of autologous fat transfer after breast cancer

Lipofilling ok

Surgical Outcome and Cosmetic Results of Autologous Fat Grafting After Breast Conserving Surgery and Radiotherapy for Breast Cancer: A Retrospective Cohort Study of 222 Fat Grafting Sessions in 109 Patients

BACKGROUND

Breast conserving surgery (BCS) and radiotherapy (RT) often lead to breast deformity. Reconstruction of these defects is a surgical challenge. Lately, the popularity of autologous fat grafting in these patients is growing. The purpose of this study was to assess clinical outcomes and aesthetic results of autologous fat grafting after BCS and RT.

MATERIALS AND METHODS

A database of all patients who underwent fat grafting after BCS and RT was prospectively maintained. Patient demographics, clinical and surgical characteristics and intra- and postoperative complications were analysed. Preoperative and 6-month postoperative photographs were evaluated by a four-member expert-panel assessing the aesthetic outcome (Harvard scale, five-point aesthetic scale and an overall score).

RESULTS

Between June 2008 and January 2016, 109 consecutive patients (114 breasts) underwent 222 fat grafting procedures. The mean clinical postoperative follow-up was 26 ± 19 months (range 10-97). The median number of fat grafting sessions sufficient for a satisfactory surgical result was two (range 1-6). Localized infections occurred in four patients, all treated effectively with oral antibiotics. Fat necrosis that required excision under local anaesthesia occurred once. The overall cosmetic appearance was rated 5.1/10 before and 7.2/10 after reconstruction (p < 0.01). A significant improvement was noted in breast symmetry, volume, shape and scarring.

CONCLUSION

Fat grafting after BCS and RT provides significant aesthetic improvement of the breast. It has a positive effect on the postsurgical scar and irradiated tissue and helps to restore the volume deficit, which makes it suitable as a reconstructive approach in this patient group.

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 .

Treatment of Breast Cancer-Related Lymphedema with Adipose-Derived Regenerative Cells and Fat Grafts: A Feasibility and Safety Study

Breast cancer‐related lymphedema (BCRL) is a debilitating late complication with a lack of treatment opportunities. Recent studies have suggested that mesenchymal stromal cells can alleviate lymphedema. Herein, we report the results from the first human pilot study with freshly isolated adipose‐derived regenerative cells (ADRC) for treating lymphedema with 6 months follow‐up. Ten BCRL patients were included. ADRC was injected directly into the axillary region, which was combined with a scar‐releasing fat graft procedure. Primary endpoints were change in arm volume. Secondary endpoints were change in patient reported outcome and safety. The study is registered with ClinicalTrials.gov (NCT02592213). During follow‐up, a small volume reduction was noted but was not significant. Five patients reduced their use of conservative management. Patient‐reported outcomes improved significantly over time. ADRCs were well tolerated and only minor transient adverse events related to liposuction were noted. In this pilot study, a single injection of ADRC improved lymphedema based on patient‐reported outcome measures, and there were no serious adverse events in the 6 months follow‐up period. In addition, half of the patients reduced their use of conservative management. ADRC therapy is a promising interventional therapy for alleviating lymphedema, but results need to be confirmed in randomized clinical trials. Stem Cells Translational Medicine2017;6:1666–1672