In our previous papers, we reported a significant association between the presence of final invasion following surgery in DCIS, diagnosed with a stereotactic vacuum-assisted biopsy as a pure in situ lesion, and a preoperative expression of molecules that trigger the early steps of EMT: Transcription factor Snail1, a direct E-cadherin repressor, and the multifunctional de-adhesive protein SPARC (secreted protein acidic and rich in cysteine), a key modulator of the tumor microenvironment. Here, SPARC is linked to ductal breast carcinoma in situ.