Each breast contains a number of cells that make up the glandular tissue of the breast, surrounded by fat cells, blood vessels, nerves and connective tissue. Breast cancer develops when cells within the glandular tissue of the breast, leading to the development of a tumor. In the early stages of breast cancer, tumor growth is typically localized within one area of the breast, but grows and becomes more invasive as the cancer develops.
Stage IIIB
Stage IIIB breast cancer occurs when cancer cells begin to migrate away from the initial tumor. Patients with IIIB breast cancer have tumor growth within the breast that may be larger than 2 inches in diameter, and are beginning to develop cancer cell growths within the lymph nodes around the breast. Lymph nodes, small collections of immune system cells, are among the first places to which breast cancer cells migrate during cancer development.
The American Cancer Society indicates that patients with stage IIIB breast cancer may have cancer cells in up to nine lymph nodes in the armpit and surrounding the breast. The breast cancer has also begun to grow into the chest wall or the skin overlying the breast. If left untreated, stage IIIB breast cancer will become more invasive and aggressive.
Stage IIIC
Stage IIIC breast cancer is an aggressive breast cancer characterized by extensive lymph node invasion. The breast tumor in stage IIIC breast cancer may be any size, and cancer cells from the tumor have spread to 10 or more lymph nodes in the armpit or surrounding the breast. During this extensive lymph node invasion, breast cancer cells may spread to lymph nodes above and below the collarbone, and the cancer cells lead to enlarge lymph nodes within the breast. Patients at this stage may notice enlarged lymph nodes under the arm, as the lymph nodes swell with cancer cells, become matted together and begin to stick to the overlying skin. Despite extensive lymph node invasion, stage IIIC breast cancer has not yet spread to other organs within the body.
Stage IV
Stage IV breast cancer is metastatic breast cancer, which occurs when breast tumor cells travel throughout the body and develop new tumors within distant organs. Breast cancer cells can circulate throughout the body by entering the blood vessels and traveling via the bloodstream, or they may travel through the lymphatic system following invasion of lymph nodes. Breast cancer commonly metastasizes to the lungs, bones, liver or brain, reports the American Cancer Society.
Patients with metastatic breast cancer may notice a range of symptoms associated with tumor growth in various organs. Patients with breast cancer that spreads to the lungs may have difficulty breathing, while patients with bone metastases may suffer from bone pain and fractures. Breast cancer metastasis to the liver leads to liver damage and eventual liver failure, while metastasis to the brain can cause persistent headaches and seizure. According to the National Cancer Institute, metastatic breast cancer treatment aims to target cancer cells throughout the whole body, to extend patient lifespan and increase patients' quality of life.
