Ductal carcinoma in situ (DCIS) refers to neoplastic epithelial cells proliferating within the mammary ducts of the breast, which have not breached the basement membrane nor invaded surrounding tissues. Traditional thinking holds that DCIS represents an early step in a linear progression towards invasive ductal carcinoma (IDC). However, as only approximately half of DCIS cases progress to IDC, important questions around the key determinants of malignant progression need to be answered. Recent studies have revealed that molecular differences between DCIS and IDC cells are not found at the genomic level; instead, altered patterns of gene expression and post-translational regulation lead to distinct transcriptomic and proteomic profiles. Therefore, understanding malignant progression will require a different approach that takes into account the diverse tumour cell extrinsic factors driving changes in tumour cell gene expression necessary for the invasive phenotype. Here, we review the roles of the tumour stroma (including mesenchymal cells, immune cells and the extracellular matrix) and myoepithelial cells in malignant progression and make a case for a more integrated approach to the study and assessment of DCIS and its progression, or lack thereof, to invasive disease.
- BREAST PATHOLOGY
- TUMOUR MARKERS
- TUMOUR IMMUNITY
- BREAST CANCER
Statistics from Altmetric.com
Handling editor Cheok Soon Lee
Contributors All authors have substantial contributions to the conception, design and drafting the work.
Funding This article was funded by the A*STAR Biomedical Research Council, National Medical Research Council Stratified Medicine Programme Office (SMPO201302) awarded to PHT. JI is a recipient of the Transition Award from the Singapore National Medical Research Council (NMRC/TA/0041/2015).
Competing interests None.
Provenance and peer review Not commissioned; internally peer reviewed.