The month of October, dubbed Pinktober, commemorates Breast Cancer Awareness globally. According to the American Society of Clinical Oncology (ASCO) cancer begins when healthy cells change and grow out of control, forming a mass or sheet of cells called a tumour. A tumour can be cancerous or benign. A cancerous tumor is malignant, it can grow and spread to other parts of the body. A benign tumour can grow but will not spread.
Breast cancer is a disease in which cells in the breast grow out of control and can develop in women and men. However, male breast cancer is rare. Less than one per cent of all breast cancers develop in men. Some types of breast cancer include: ductal carcinoma which starts in the cells lining the milk ducts and make up the majority of breast cancers and lobular carcinoma which starts in the lobules, which are the small, tube-like structures that contain milk glands. When breast cancer is limited to the breast and/or nearby lymph node regions, it is called early stage or locally advanced, ASCO notes. If it spreads to an area farther from where it started to another part of the body, doctors say that the cancer has “metastasized”.
The disease is called metastatic breast cancer or stage IV (4) breast cancer if it has already spread beyond the breast and nearby lymph nodes at the time of diagnosis of the original cancer. Doctors may also call metastatic breast cancer “advanced breast cancer”. However, this term should not be confused with “locally advanced breast cancer” which is breast cancer that has spread to nearby tissues or lymph nodes but not to other parts of the body. Metastatic breast cancer may spread to any part of the body. It most often spreads to the bones, liver, lungs, and brain. Even after cancer spreads, it is still named for the area where it began. This is called the “primary site” or “primary tumor”. For example, if breast cancer spreads to the lungs, doctors call it metastatic breast cancer, not lung cancer. This is because the cancer started in breast cells.
Cancer cells are able to travel in the fluids far from the original tumor. The cells can then settle and grow in a different part of the body and form new tumours. Most commonly, doctors diagnose metastatic breast cancer after a person previously received treatment for an earlier stage (non-metastatic) breast cancer. Doctors sometimes call this a “distant recurrence” or “metastatic recurrence.” This can happen at any time after someone is diagnosed with breast cancer, even a few decades later. “Sometimes, a person’s first diagnosis of breast cancer is when it has already spread to other parts of the body. Doctors call this ‘de novo’ metastatic breast cancer or stage IV breast cancer,” notes ASCO.