There are several ways in which DCIS acts differently than invasive breast cancer. One way is that DCIS tends to spread along the breast ducts. As it spreads along the ducts, it can travel into a large portion of the breast through the duct system. Also, DCIS has a tendency to be multifocal. This means that the tumor can be found in more than one part of the breast--in reality, there may be more than one tumor growth in the breast tissue. The multifocal aspect of DCIS very much influences how these tumors are treated.
In contrast, invasive breast cancers are much less likely to be multifocal ( it can happen, but not that often).
|Feature||DCIS||Invasive Breast Cancer|
|Spread to axilary lymph nodes||No||Often|
|Spread to distant organs||No||Often|