Figure 1.

Existing models of ductal carcinoma in situ (DCIS) progression to invasive ductal carcinoma (IDC). The independent lineage, evolutionary bottleneck, and multiclonal invasion models involve cell-intrinsic mechanisms of DCIS progression to IDC. The microenvironment-mediated invasion model is cell extrinsic and involves cellular factors, such as immune cells, fibroblasts, and endothelial cells, and noncellular factors, such as hormones, growth factors, extracellular matrix, and more. There is varying evidence that supports each model of progression and the simultaneous occurrence of multiple models.