Invasive Breast Cancer

Invasive breast cancer occurs when abnormal cells from inside the milk ducts or lobules break out into nearby breast tissue.

Cancer cells can travel from the breast to other parts of the body through the bloodstream or the lymphatic system. They may travel early in the process when a tumor is small or later when a tumor is large.

If breast cancer spreads, the lymph nodes in the underarm area (the axillary lymph nodes) are the first place it’s likely to go.

Learn about treatment for invasive breast cancer.

Metastatic breast cancer

Metastatic breast cancer (also called stage IV or advanced breast cancer) is invasive breast cancer that has spread beyond the breast and nearby lymph nodes to other parts of the body (most often the bones, lungs, liver or brain).

Metastatic breast cancer is not a specific type of breast cancer, it’s the most advanced stage of breast cancer.

Learn about treatment for metastatic breast cancer.  

Most common invasive breast cancers

• Invasive ductal carcinoma (also called infiltrating ductal carcinoma) begins in the milk ducts and is the most common invasive breast cancer.
• Invasive lobular carcinoma begins in the lobules and is the second most common invasive breast cancer.

Less common invasive breast cancers

• Inflammatory breast cancer is an aggressive form of locally advanced breast cancer. It’s called inflammatory breast cancer because the main warning signs are swelling (inflammation) and redness in the breast. With inflammatory breast cancer, warning signs tend to arise within weeks or months. With other breast cancers, warning signs may not occur for years.
• Paget disease of the breast (Paget disease of the nipple) is a carcinoma in situ in the skin of the nipple or in the skin closely surrounding the nipple. It’s usually found with an underlying breast cancer.
• Metaplastic breast cancers tend to be larger and have a higher tumor grade than more common breast cancers. Metaplastic breast cancers can be hard to diagnose because the tumor cells can look very different from the tumor cells of more common breast cancers.

Prognosis for invasive breast cancer

The prognosis (chance of survival) after invasive breast cancer depend on each person’s diagnosis and treatment.

For example, people diagnosed with early breast cancers have a better prognosis than those diagnosed with more advanced breast cancers.

Learn more about factors that affect prognosis.

Treatment for early and locally advanced invasive breast cancers

Treatment for early and locally advanced invasive breast cancer includes some combination of surgery, radiation therapy, chemotherapy, hormone therapy, HER2-targeted therapy and/or other drug therapies.

The specific treatments depend on the cancer stage and the characteristics of the tumor, such as hormone receptor status and HER2 status.

Learn more about treatment for early and locally advanced breast cancers.

Learn about treatment for metastatic breast cancer.

Learn more about breast cancer stage.

Learn more about factors that affect breast cancer treatment.

Updated 07/20/22