Metastatic breast cancer very often can start in the breast ducts like ductal carcinoma in situ (DCIS). Once out of the breast, the metastatic cancer often circulates 1st to the axillary lymph nodes. May be one or more of the lymph nodes which are usually cut out in time of a metastatic breast surgery to define are the nodes involved in or not.
In many cases, the metastatic breast cancer can spread to many other parts of the body with no involving the axillary lymph nodes. If the cancerous metastatic tumor is situated in the medial portion of the breast (which is quite close to the nipple), it can circulate to the domestic mammary nodes that are situated among the ribs and exactly under the sternum. In many cases, the metastatic breast cancer can spread via the bloodstream with no being detected in the lymphatic system.