CHAMPion and WiSDen studies: investigating the relationship between a stromal wound healing phenotype and breast density

Abstract

Background: Tumour stroma resembles a �wound that will not heal�, with myo?broblasts phenotypically similar to cancer-associated ?broblasts (CAFs). Fibroblasts produce collagen and are hyperactivated in high breast density tissue. Breast cancer ?broblasts show increasing expression of procoagulant and CAF markers in the normal-DCIS (ductal carcinoma in situ, breast cancer precursor)-invasive cancer transition. High mammographic density is associated with an increased risk of breast cancer, but the mechanism for this is unclear.Purpose: We hypothesise that high density breast tissue has a wound-like, procoagulant stroma, causing increased collagen formation (visible mammographic density) and promoting breast cancer development, including the transition from DCIS to invasion. This may provide novel therapeutic options for breast cancer prevention. Methods: Fresh tumour/DCIS tissue plus distant normal tissue are collected from patients undergoing mastectomies at Wythenshawe Hospital with the support of pathologists and the Manchester Cancer Research Centre Biobank. Primary broblasts are grown from these and characterised with their e?ect on established breast cancer cell lines investigated. In the ?nal phase of the study, mammographic density and residual FFPE tissue will be compared to the experimental results. Results: Primary ?broblast culture is achievable for most tissue samples, with a bank of frozen cell stocks, conditioned media, lysates and FFPE built up for later study phases. Initial functional experiments using the modi?ed prothrombin time assay indicate ?broblasts cells and their secreted factors in conditioned media initiate coagulation. Conclusions: Cultured primary ?broblasts have been shown to be functionally procoagulant, as suggested by earlier work on ?xed tissue. Functional experiments with the cultured ?broblasts and comparisons to mammographic density will be carried out in the next phases of this study.