Comparative Analysis of Adipose Tissue Depots in Immediate versus Delayed Breast Reconstruction.

[BACKGROUND] Mastectomy followed by breast reconstruction is the standard treatment for breast cancer. Choosing autologous tissue requires an in-depth understanding of the molecular and structural characteristics of the different adipose tissue depots.

[METHOD] White adipose tissue (WAT) from five different locations (above and below the abdominal Scarpa's fascia, thighs, breast skin envelope, and omentum) was collected from 24 patients undergoing breast reconstruction and grouped based on immediate (IBR) or delayed (DBR) reconstruction. The adipocyte area was analyzed in histologically processed WAT sections. Transcription and protein expression profiles, related to inflammation, fibrosis, browning, and adipose-derived stem cells (ADSCs) content were determined by RT-qPCR and Western blotting.

[RESULTS] Compared to IBR, omental WAT from DBR patients exhibits larger adipocytes, and higher expression of TIMP1, FN1, CD206, and CD45, as well as lower levels of CIDEA. Breast fat also differs between the two groups, with lower levels of IL6 and CIDEA, and overexpression of FN1 in the DBR group. Within the IBR group, breast fat shows higher levels of IL6, TIMP1 and CIDEA, but lower expression of FN1 and COL3A1 than subcutaneous WAT.

[CONCLUSION] Omental fat in the IBR cohort has properties similar to those of subcutaneous WAT, indicating that the omentum is a promising candidate for rapid breast restoration. In the DBR group, the omentum molecular signature suggests a change towards a pro-fibrotic phenotype and a reduced remodeling capacity, suggesting that it should not be the primary choice for breast reconstruction. This study emphasizes the importance of careful WAT selection to minimize adverse outcomes, including cancer recurrence, and underscores the diverse physiology of fat depots.