Infiltrating or invasive ductal carcinoma (abbreviated IDC) is
the most common type of invasive breast cancer. About 80% of invasive breast cancers are IDCs.
IDC originates in the ducts of the breast. As its name implies, IDC is termed invasive, because the cancer has broken through the wall of the duct and invaded the fatty tissue of the breast. At this point, IDC can metastasize (spread to other parts of the body through the lymphatic system and bloodstream). Treatments for IDC are available.