How often does breast cancer spread to lymph nodes?
About 30% of breast cancers metastasize to nearby blood vessels and lymph nodes, a process called lymphovascular invasion.
A large-scale study conducted in China analyzed 19 smaller studies involving an overall of 4215 patients with breast cancer. Lymphovascular invasion was noted in 29.56% of patients. This implies that lymphovascular invasion is found in nearly 29 out of every 100 patients with breast cancer.
What does lymphovascular invasion mean in breast cancer?
Your breast has a network of blood vessels (called the vascular system) and lymph vessels (lymphatic system). This network carries the blood and fluid (lymph fluid) back and forth from your breast to the rest of your body. The lymph contains tissue by-products and waste materials, as well as the immune system cells. The vascular and lymphatic systems nourish the breast and remove waste materials out of the breast.
When breast cancer that is localized only to the breast tissue spreads to the vascular and lymphatic systems in the breast, the condition is known as lymphovascular invasion in breast cancer. Another term for lymphovascular invasion is “angiolymphatic invasion.”
How is lymphovascular invasion in breast cancer diagnosed?
Lymphovascular invasion in breast cancer is diagnosed by taking a biopsy of the tissue in the lymphatic or blood vessels in the breast that surround the tumor in the breast. A biopsy is removing a piece of the breast tissue for laboratory examination under the microscope. It can be performed during a surgery that involves removing the tumor from your breast or separately as an exclusive biopsy procedure before deciding the treatment.
Lymphovascular invasion is an important criterion for the treatment of patients with breast cancer. Therefore, most laboratory reports for cancer will mention whether lymphovascular invasion was seen in the tissue sample. They will report either of the following:
- Positive for lymphovascular invasion: Lymphovascular invasion was seen in the tissue examined. This means cancer cells were present in the small blood vessels or lymph vessels.
- Negative for lymphovascular invasion: Lymphovascular invasion was not seen in the tissue examined. This means cancer cells were absent in the small blood vessels or lymph vessels.
Is lymphovascular invasion in breast cancer bad?
Lymphovascular invasion in patients with breast cancer can cause the cancer to spread in other parts of the body. This is because the cancer cells can spread anywhere in the body through the lymph or blood. The process is known as metastasis. Metastasis of breast cancer is difficult to treat, and very few patients survive this stage.
The lymph vessels are connected to the lymph nodes. Cancer from the lymph vessels can spread to the lymph nodes. The lymph nodes are small bean-shaped collections of the immune system cells that are in the following areas:
- Above and below the collar bone
- In the axilla (armpits)
- Near to the chest bone
The lymph nodes transport the immune cells all over the body. Thus, cancer cells can spread through these lymph nodes. Doctors perform a biopsy of the lymph node and send it to the laboratory for examination under the microscope. If the lymph node tissue seen under the microscope contains cancer cells, they report it as node-positive cancer. If the cancer cells are absent in the lymph node tissue, they report it as node-negative cancer.
Several research studies have consistently reported that lymphovascular invasion in breast cancer is bad. It can lead to relapse of breast cancer after treatment and reduce the years of survival in patients with node-negative cancer.
Lymphovascular invasion is used by many oncologists to determine the treatment of patients with breast cancer. Depending on the presence or absence of lymphovascular invasion, oncologists can decide whether to go for other treatments after the surgery. These treatments include radiation therapy and chemotherapy. Radiation therapy involves the use of high-energy waves to destroy the cancerous tissue. Chemotherapy involves the use of medicines that kill the cancer cells all over the body.