Table 1 The morphology and functon comparison of nBAs, TSAs, and CAAs

Definition

Normal breast adipocytes far away from BC tissue

Adipocytes located at the stroma of tumor

Abnormal adipocytes located at the front of the tumor invasion

Morphology

Normal size, round shape, riched in lipid droplets that occupy 90% of the cell volume

Smaller size, spindle or ellipsoidal, reduced lipid contends

Dedifferentiated state, smaller size, fibroblast-like phenotype, smaller and reduced lipid contends

Function

Maintain the normal shape of the breast, normally secretion of diverse factors, possess energy storage functions and sustain energy balance

Important components of BC stroma, interact with BC cells and other stromal cells by releasing multiple adipokines, lipid metabolites and exosomes

Involve in malignant progression of BC by aberrantly secreted various cytokines, adipokines, lipid metabolites and exosomes

Impact on BC

The tumor-promoting effect is weaker than that of TSA and CAAs, and is the soil for BC cell seeds

Affect BC oncogenesis, proliferation and therapeutic outcomes in paracrine form by interacting within the complex network to support BC progression

Release molecules in promoting BC proliferation, migration, invasion, metastasis ability of BC cells by interacting with tumor cells, altered metabolic and immune status.