Effects of Stromal Vascular Fraction on Breast Cancer Growth and Fat Engraftment in NOD/SCID Mice

Primary injection laryngoplasty after chordectomy for small glottic carcinomas

OBJECTIVES

The purpose of this study was to analyze the short- and middle-term effects of primary injection laryngoplasty in patients having tumor resection within the same surgery concerning the vocal outcome. Injection laryngoplasty was performed after harvesting autologous adipose tissue via lipoaspiration.

METHODS

A prospective study was performed with 16 patients (2 female; 14 male) who received tumor resection and an injection laryngoplasty using autologous adipose tissue during a single stage procedure. Multidimensional voice evaluation including videostroboscopy, patient self-assessment, voice perception, aerodynamics, and acoustic parameters was performed preoperatively, as well as 1.5, 3 and 6 months postoperatively.

RESULTS

Results show an improvement in the roughness-breathiness-hoarseness (RBH) scale, voice dynamics and subjective voice perception 6 months postoperatively. Maintenance of Voice Handycap Index, jitter and shimmer could be observed 6 months postoperatively. There was no deterioration in RBH and subjective voice perception 2 and 6 weeks postoperatively. No complications occurred in the fat harvesting site.

CONCLUSIONS

Using the lipoaspiration and centrifugation approach, primary fat injection laryngoplasty shows short-term maintenance und middle-term improvement in voice quality in patients with vocal fold defect immediately after chordectomy 6 months postoperatively. Cancer recurrence rate is comparable to the reported cancer recurrence rate for laryngeal carcinoma and thus not elevated through primary augmentation.

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 .

OUP accepted manuscript

Adipose-derived stem or stromal cells (ASCs) possess promising potential in the fields of tissue engineering and regenerative medicine due to their secretory activity, their multilineage differentiation potential, their easy harvest, and their rich yield compared to other stem cell sources. After the first identification of ASCs in humans in 2001, the knowledge of their cell biology and cell characteristics have advanced, and respective therapeutic options were determined. Nowadays, ASC-based therapies are on the verge of translation into clinical practice. However, conflicting evidence emerged in recent years about the safety profile of ASC applications as they may induce tumor progression and invasion. Numerous in-vitro and in-vivo studies demonstrate a potential pro-oncogenic effect of ASCs on various cancer entities. This raises questions about the safety profile of ASCs and their broad handling and administration. However, these findings spark controversy as in clinical studies ASC application did not elevate tumor incidence rates, and other experimental studies reported an inhibitory effect of ASCs on different cancer cell types. This comprehensive review aims at providing up-to-date information about ASCs and cancer cell interactions, and their potential carcinogenesis and tumor tropism. The extracellular signaling activity of ASCs, the interaction of ASCs with the tumor microenvironment, and 3 major organ systems (the breast, the skin, and genitourinary system) will be presented with regard to cancer formation and progression.

Human Adipose-Derived Stromal/Stem Cell Culture and Analysis Methods for Adipose Tissue Modeling In Vitro: A Systematic Review

Human adipose-derived stromal/stem cells (hASC) are widely used for in vitro modeling of physiologically relevant human adipose tissue. These models are useful for the development of tissue constructs for soft tissue regeneration and 3-dimensional (3D) microphysiological systems (MPS) for drug discovery. In this systematic review, we report on the current state of hASC culture and assessment methods for adipose tissue engineering using 3D MPS. Our search efforts resulted in the identification of 184 independent records, of which 27 were determined to be most relevant to the goals of the present review. Our results demonstrate a lack of consensus on methods for hASC culture and assessment for the production of physiologically relevant in vitro models of human adipose tissue. Few studies have assessed the impact of different 3D culture conditions on hASC adipogenesis. Additionally, there has been a limited use of assays for characterizing the functionality of adipose tissue in vitro. Results from this study suggest the need for more standardized culture methods and further analysis on in vitro tissue functionality. These will be necessary to validate the utility of 3D MPS as an in vitro model to reduce, refine, and replace in vivo experiments in the drug discovery regulatory process.

A Prospective Study of the Efficacy of Cell-Assisted Lipotransfer with Stromal Vascular Fraction to Correct Contour Deformities of the Autologous Reconstructed Breast

BACKGROUND

Autologous lipotransfer has increasingly become popular for breast reconstruction. Moreover, owing to the emergence of information regarding the efficacy of stromal vascular fraction (SVF) in terms of oncological safety and survival rate, procedures based on cell-assisted lipotransfer (CAL) have been widely employed recently. However, quantitative data of CAL with SVF are lacking. We evaluated the efficacy of CAL using SVF on survival rate in breast reconstruction.

METHODS

A 12-month prospective study was conducted for 20 patients (20 breasts) requiring breast asymmetry correction due to volume deficit following autologous breast reconstruction using a transverse rectus abdominis myocutaneous flap or latissimus dorsi flap after total mastectomy. After the patients were equally divided into two groups-fat graft with SVF (Group 1, n = 10) and without SVF (Group 2, n = 10)-, the variance of breast volume was measured using three-dimensional scanning to analyze fat graft retention rate. Moreover, patient satisfaction and complications were investigated.

RESULTS

Fat graft retention rate was higher in Group 1 than in Group 2 at both postoperative 6 months (73.8% vs. 62.2%; p = 0.03) and 12 months (65.4% vs. 48.4%; p = 0.03). Group 1 showed higher patient satisfaction. Regarding complications, fat necrosis occurred in 1 patient each in both groups. However, locoregional recurrence was not observed in any patient during follow-up.

CONCLUSIONS

CAL with SVF is effective in increasing survival rates of autologous fat grafts for correction of volume deficit after breast reconstruction. Moreover, it is associated with improved patient satisfaction in terms of the esthetic aspect.

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.

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.

The Impact of Human Lipoaspirate and Adipose Tissue-Derived Stem Cells Contact Culture on Breast Cancer Cells: Implications in Breast Reconstruction

BACKGROUND

Autologous fat transfer in the form of lipoaspirates for the reconstruction of the breast after breast cancer surgery is a commonly used procedure in plastic surgery. However, concerns regarding the oncologic risk of nutrient-rich fat tissue are widely debated. Previous studies have primarily focused on studying the interaction between adipose-derived stem cells (ASCs) and breast cancer cells.

METHODS

In this study, we performed a comprehensive analysis of the paracrine- and contact-based interactions between lipoaspirates, ASCs and breast cancer cell lines. An inverted flask culture method was used to study the contact-based interaction between lipoaspirates and breast cancer cells, while GFP-expressing breast cancer cell lines were generated to study the cell-cell contact interaction with ASCs. Three different human breast cancer cell lines, MCF-7, MDA-MB-231 and BT-474, were studied. We analyzed the impact of these interactions on the proliferation, cell cycle and epithelial-to-mesenchymal (EMT) transition of the breast cancer cells.

RESULTS

Our results revealed that both lipoaspirates and ASCs do not increase the proliferation rate of the breast cancer cells either through paracrine- or contact-dependent interactions. We observed that lipoaspirates selectively inhibit the proliferation of MCF-7 cells in contact co-culture, driven by the retinoblastoma (Rb) protein activity mediating cell cycle arrest. Additionally, ASCs inhibited MDA-MB-231 breast cancer cell proliferation in cell-cell contact-dependent interactions. Quantitative real-time PCR revealed no significant increase in the EMT-related genes in breast cancer cells upon co-culture with ASCs.

CONCLUSION

In conclusion, this study provides evidence of the non-oncogenic character of lipoaspirates and supports the safety of clinical fat grafting in breast reconstruction after oncological surgical procedures. In vivo studies in appropriate animal models and long-term post-operative clinical data from patients are essential to reach the final safety recommendations.