Expression of cancer-associated fibroblast-related proteins in adipose stroma of breast cancer

Cancer-associated fibroblasts (CAFs) play key roles in tumor microenvironment; they are thought to originate from adipocytes. This study aimed to evaluate CAF-related protein expression and its implications in breast cancer. Of the 939 enrolled breast cancer patients, 642 had fibrous and 297 had adipose stroma. The status of estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2 (HER-2), Ki-67, podoplanin, prolyl 4-hydroxylase, fibroblast activation protein α (FAPα), S100A4, platelet-derived growth factor receptor α (PDGFRα), PDGFRβ, and chondroitin sulfate proteoglycan (NG2) was evaluated via tissue microarrays. Tumors were divided into luminal A, luminal B, HER-2, or triple-negative breast cancer subtypes according to their molecular status. Luminal A subtype was more prevalent in breast cancer of adipose stroma type, whereas other molecular subtypes were more common in fibrous stroma type ( p