As you know, breast cancer develops and can spread rapidly through the body. In order for doctors to make a diagnosis and come up with a treatment plan, they must know which stage of breast cancer you are in. This process is called staging, of which the doctor can determine how large the tumor is and how far it has spread. Once the doctor has performed a biopsy of the tumor or lymph node, they can start making the determination. Let’s review how breast cancer spreads through the body and its five stages.
How Cancer Spreads Throughout the Body
The process of cancer spreading throughout the body is called Metastasis. When cancer reaches another part of your body and form a tumor, that new tumor is called a metastatic tumor.
A metastatic tumor is not a new type of cancer in your body. If you have breast cancer and the cancer cells spread to your lungs, it’s not lung cancer, it’s still breast cancer. You just have breast cancer cells in your lungs. When you put the cells under a microscope, they will look like the cells in your breast. The same holds true if it travels to your liver, stomach, ovaries, prostate, or any other area of your body.
Once cancer cells break away from the tumor, the cancer spreads through the body in three ways: via the tissue, the lymphatic system, or the blood.
1. Tissue – When the cancer cells spread in the local area, it travels via tissue.
2. Lymphatic system – Cancer can spread from its place or origin and get into your lymphatic system. This system is responsible for fighting infections in your body. So, this system carries your cells everywhere.
3. Blood – Your blood circulates throughout your entire body. Cancer cells can get into the blood and travel via your blood vessels.
The 5 Stages of Breast Cancer
The American Joint Committee on Cancer (AJCC) recognizes breast cancer as having five main stages, stages one through five. However, they are generally written in Roman numerals, 0 through IV. Once your cancer spreads or gets worse, it is progressing. Staging consists of the three combinations of the following classifications:
1. The tumor’s size (T)
2. The number of lymph nodes found (N)
3. How far the cancer cells have spread to other parts of the body (M)
Stages 0 through IV are considered the early forms or stages of the disease. Stages III and IV are considered advanced stages of breast cancer.
Stage 0 breast cancer is considered noninvasive. There is no threat that the cells will grow or spread.
Stage I is invasive breast cancer. The tumor is smaller than 2 cm (about the width of your finger). There are two subcategories for Stage I breast cancer: 1A and 1B.
• 1A – The cancer cells have not spread outside the breast
• 1B – The cancer cells have traveled outside the breast into the lymph nodes. There may or may not be a tumor present in the breast.
Stage II is invasive breast cancer. This stage also has two subcategories.
• 2A – The tumor is smaller than 2 cm, or there is no tumor found in the breast. However, cancer cells may be present in the lymph nodes. Breast cancer may also be considered stage 2A if the tumor is between 2 cm-5 cm and the cancer cells have not spread to the lymph nodes.
• 2B – The tumor is between 2 cm-5 cm, and the cancer cells have spread to the lymph nodes. Breast cancer may also be considered stage 2B if the tumor is larger than 5 cm, but the cells have not spread to the lymph nodes.
In stage III, the cancer is now locally advanced. This means the cancer has spread to other tissues in the breast or the lymph nodes; however, it has not made its way throughout the body to other sites. Stage III breast cancer has three subcategories.
• 3A – The tumor is larger than 5 cm and has spread to one, two, or three lymph nodes. The tumor could also be of any size, but has spread through multiple lymph nodes.
• 3B – The tumor is of any size and has spread through breast tissues, the chest and skin muscles, and there may be signs in the lymph nodes in the breast or underarm.
• 3C – The tumor is of any size and has spread to more than 10 underarm lymph nodes. Alternatively, the cancer may be found in the lymph nodes around the collarbone, in the breast, and/or under the arm.
Stage IV is considered metastatic breast cancer or advanced breast cancer. The cancer has spread beyond its origin point. It’s not localized anymore. This is when the lungs, brain, liver, and other sites are affected. At this point, treatment can extend a patient’s life; however, the cancer is incurable.
Once your breast cancer stage has been identified, you and your doctor will discuss treatment options. As you can see, knowing the early signs of breast cancer may prevent you from reaching stage IV breast cancer.