Invasive breast cancer is cancer that has spread beyond the lobes or ducts of the breast and into the surrounding tissue. The cancer may also have moved to the lymph nodes in and around the breast, or to other parts of the body. Invasive cancers have broken through normal tissue and are spreading through the bloodstream and lymphatic system.

A breast cancer that has spread to another organ or to other tissue, and is the same cancer as the original, or primary, is termed a metastasis (metastases for more than one) or metastatic breast cancer. Breast cancer can metastasize to many areas of the body, but most often spreads to the bones, lungs, or brain.

Most invasive breast cancers are invasive ductal carcinomas, meaning that the cancer began in the milk ducts of the breast. A smaller percentage is invasive lobular carcinoma, which begins in the lobules of the breast.

Staging of the cancer is determined by the size and location of the tumors.

Care: There are many treatments for invasive breast cancer. Some treatments are aimed at attempting to remove or eradicate the cancer, others to slow the progression and or provide symptom relief and improve quality of life.

Treatment for invasive breast cancer will include some combination of surgery , radiation therapy , and chemotherapy.