The axillary lymph nodes are in the armpits, near the breasts. This means they are often the first location where breast cancer spreads if it moves beyond the breast tissue.
Lymph nodes are small structures inside the body that connect to a network of lymph vessels. Lymph nodes are responsible for filtering lymph fluid. They also detect chemical changes that signal an infection is present.
The lymph nodes in the armpits are called axillary lymph nodes.
The number of axillary lymph nodes can vary from person to person. Typically, a person has
After a breast cancer diagnosis, a surgeon may remove lymph nodes, or a radiologist may perform a biopsy on a lymph node to determine whether the cancer cells have spread to the axillary lymph nodes. This can help confirm the diagnosis and stage of the cancer.
This article looks into the link between breast cancer and the axillary lymph nodes as well as treatments and outlook.
Breast cancer can metastasize, or spread, to other parts of the body. It spreads when cancer cells from the breast get into the lymphatic channels or the bloodstream.
Cancer cells may travel in the bloodstream or through the lymphatic system. Cancer that travels via the lymphatic system may end up growing inside the lymph nodes.
Axillary lymph nodes are in the armpits, which are close to the breasts. Because the axillary lymph nodes are so close, breast cancer
If cancer has spread to the axillary lymph nodes, a doctor may recommend removing some or all of the lymph nodes during a mastectomy or lumpectomy. A mastectomy is a surgical procedure that removes a breast.
Lymph nodes are responsible for draining lymph fluid. As a result, removing them
According to Breast Cancer Now, symptoms of breast cancer that has spread to the axillary lymph nodes can include:
- a lump or swelling under the arm, breastbone, or collarbone area
- swelling of the arm or hand
- pain
If a person notices any of these symptoms, they should speak with their doctor as soon as possible.
When checking whether breast cancer has spread to the axillary lymph nodes, a doctor may perform a physical examination. During the exam, a doctor may check a person’s armpits for swelling.
A doctor may also order an imaging scan, such as:
These scans may be able to detect changes in the lymph nodes,
- thickening inside the lymph node
- an increase in blood vessels
- the loss of hilum, the structure where lymph vessels exit the node
- the loss of an oval-shaped appearance
A doctor can use several diagnostic methods to determine whether cancer has spread to the axillary lymph nodes:
Sentinel node biopsy
A sentinel lymph node biopsy involves the removal of the sentinel lymph nodes, which are the first nodes that drain the breast tissue.
To find the sentinel lymph nodes, a surgeon injects two substances into a person: a radioactive isotope and a blue dye. These substances travel to the sentinel lymph nodes, allowing the surgeon to locate and examine them.
A surgeon typically uses a Geiger counter, which is an instrument to detect and measure radiation, to identify the radioactive sentinel lymph nodes. Meanwhile, the blue dye stains the sentinel lymph nodes, which makes them visible to the naked eye.
A surgeon removes the sentinel nodes and sends the sample to a pathologist. Sentinel nodes are the ones that are blue, “hot” (indicating high radiation levels), or palpable (able to be felt).
If the pathologist finds cancer in the sentinel nodes, a person may need to have more lymph nodes removed.
Axillary dissection
Axillary dissection is a procedure that involves removing all lymph nodes in the axilla (the armpit). The purpose of this is to help stage the cancer and, at times, decrease the chance of cancer redeveloping in this area.
The surgeon removes an area of fat that contains many or all of the lymph nodes. At least 10 lymph nodes are removed during an axillary dissection, with an average of up to 25 nodes typically being extracted.
Once the surgeon removes the nodes, a pathologist can determine whether cancer has spread beyond the sentinel lymph nodes.
Staging
Cancer stages indicate the
Doctors use the tumor, nodes, and metastasis (TNM) system to work out the stage of breast cancer:
- T: The tumor staging defines the size of the original tumor.
- N: The node staging tells whether breast cancer has reached the lymph nodes and how many nodes show signs of cancer cells.
- M: The metastasis staging gives information on whether cancer has spread to other parts of the body from its site of origin.
The node staging has several subcategories to provide more specific detail about the stage of the disease:
- NX: There is no information about the nearby lymph nodes, or assessment of the axillary lymph nodes is not possible. For example, a person may have already undergone surgery to remove them.
- N0: Cancer has not spread to the lymph nodes. However, a doctor may request further testing to see whether microscopic amounts of cancer cells are present in the lymph nodes. These cells are known as micrometastases.
- N1: Micrometastases or cancerous cells are present in 1 to 3 axillary lymph nodes or the nodes inside the breast.
- N2: In this stage, 4 to 9 axillary lymph nodes have cancerous cells. A doctor also uses this stage to indicate that the nodes inside the breast have developed cancer. These nodes are known as internal mammary nodes.
- N3: This stage can indicate a range of outcomes, such as:
- Testing found cancer in 10 or more axillary lymph nodes.
- Cancer is in the lymph nodes under the collarbone.
- Cancer is in the internal mammary nodes and one or more axillary lymph nodes.
- Four or more axillary lymph nodes are cancerous, and internal mammary nodes have micrometastases.
- Testing found cancerous nodes above the collarbone.
The staging of axillary lymph nodes becomes higher when cancer has spread to more nodes. Cancer staging also increases as the cancer affects different types of nodes.
Breast cancer treatment often involves various options. Mastectomy is one of them. This is the removal of a breast. An alternative is a lumpectomy, which is the removal of the tumor and surrounding tissue. This is known as a breast-conserving surgery.
Radiation therapy is commonly used after breast-conserving surgery to kill any remaining cancer cells and reduce the risk of the cancer coming back. Most people who have breast-conserving surgery will receive radiation therapy as part of their treatment plan.
Most people with stage 1, 2, or 3 breast cancer will receive drug therapy to prevent the cancer from spreading. Drug therapies for breast cancer include:
- chemotherapy
- hormone therapy
- targeted drugs
- immunotherapy
- a combination of these therapies
The amount of treatment a person needs will depend on how far their cancer has spread, their personal preferences, and other factors.
When cancer spreads from its starting point, it can
Other factors that can affect a person’s outlook include:
- the cancer’s response to treatment
- the extent and location of a tumor
- a person’s overall health and medical history
- the specific subtype of breast cancer (some types of cancer can be more aggressive than others)
A 5-year relative survival rate estimates a person’s likelihood of survival 5 years after diagnosis compared with people who do not have that diagnosis.
According to the
Meanwhile, if a person’s breast cancer spreads to distant parts of their body, this is classified as incurable metastatic breast cancer, and the 5-year survival rate decreases to 31%.
What causes axillary lymph nodes to swell?
A person
However, swollen axillary lymph nodes can also point to noncancerous conditions, such as infectious or autoimmune systemic diseases.
What size of an axillary lymph node is concerning?
If the outer layer of an axillary lymph node is thicker than 2.5 to 3.0 millimeters, it may indicate cancer.
Cancer cells can travel from the breast via the lymphatic system. This may result in a person developing cancer in their axillary lymph nodes. When this happens, a person may notice a lump or swelling in their armpit, breastbone, or collarbone.
A doctor can use various diagnostic tests to determine whether a person’s breast cancer has spread to their lymph nodes. If the cancer has spread, a surgeon may remove a person’s lymph nodes. Doctors also prescribe radiation therapy and drugs to treat breast cancer.
If a person notices any symptoms of breast cancer spreading to their axillary lymph nodes, they should speak with a doctor as soon as possible. Early diagnosis can make cancer easier to treat.