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

The Learning Curve of Total Breast Reconstruction With Autologous Fat Transfer

INTRODUCTION

Total breast reconstruction with autologous fat transfer (AFT) is a relatively new breast reconstruction method. Although AFT was predominantly used to correct postsurgical defects, the surgical skills of a total breast reconstruction with AFT are different and can be facilitated for novices to accelerate their learning process. This study aims to assess the learning curve of plastic surgeons in total breast reconstruction with AFT in the Netherlands.

METHODS

A mixed-methods study was performed based on the multicenter randomized clinical BREAST trial data. For the qualitative analysis, semistructured interviews were conducted. To test hypotheses derived from the qualitative data, retrospective data analysis was performed using multilevel linear regression analysis of the patients undergoing AFT as a total breast reconstruction method.

RESULTS

The interviews revealed that plastic surgeons need to perform the procedure several times to learn and experience the technical details of total breast reconstruction with AFT. Learning and improving this technique works best by scrubbing in with an expert. Before plastic surgeons learn the optimal volume of fat reinjection over time, they tend to inject too little fat and subsequently too much fat over multiple procedures. With more experience, the rigottomy technique becomes more important. Besides technical details, managing patient expectations before starting treatment is paramount. Multilevel linear regression revealed a significant decrease (P < 0.001) in the number of surgical procedures and the total injected volume (P = 0.002) to complete a total breast reconstruction with AFT.

CONCLUSIONS

This is the first study that explores the learning curve involved in using AFT as a total breast reconstruction method. The feeling of when fat transfer is sufficient, and how to release scars for a good result without causing seromas, is best learned by scrubbing in with experienced colleagues during several procedures, interchanged with starting one's own practice.

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.

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

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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.

Lipofilling in Breast Oncological Surgery: A Safe Opportunity or Risk for Cancer Recurrence?

Lipofilling (LF) is a largely employed technique in reconstructive and esthetic breast surgery. Over the years, it has demonstrated to be extremely useful for treatment of soft tissue defects after demolitive or conservative breast cancer surgery and different procedures have been developed to improve the survival of transplanted fat graft. The regenerative potential of LF is attributed to the multipotent stem cells found in large quantity in adipose tissue. However, a growing body of pre-clinical evidence shows that adipocytes and adipose-derived stromal cells may have pro-tumorigenic potential. Despite no clear indication from clinical studies has demonstrated an increased risk of cancer recurrence upon LF, these observations challenge the oncologic safety of the procedure. This review aims to provide an updated overview of both the clinical and the pre-clinical indications to the suitability and safety of LF in breast oncological surgery. Cellular and molecular players in the crosstalk between adipose tissue and cancer are described, and heterogeneous contradictory results are discussed, highlighting that important issues still remain to be solved to get a clear understanding of LF safety in breast cancer patients.