- Why It's Performed
- Finding the Sentinel Node
- Recovery Time
What is a sentinel lymph node biopsy?
Lymph nodes are small, bean-shaped structures that contain cells from the immune system. They filter substances that travel through the lymphatic fluid and are connected to lymph vessels. Lymph nodes can also contain cancer cells that have spread from the site of the cancer into the lymphatic fluid. The sentinel lymph nodes are the first few lymph nodes ("lymph gland") to receive lymphatic drainage from a tumor, meaning that sentinel lymph nodes are the first lymph nodes to which cancer cells would spread. It stands sentinel over the tumor, so to speak. The biopsy is performed to determine if there are cancer cells in the node. If the sentinel lymph node does not contain cancer cells (a negative sentinel lymph node biopsy), then the cancer has not likely spread to lymph nodes or other organs via the lymphatic system.
Sentinel node biopsy is a common technique to assess the extent of spread of breast cancer and can spare the patient more extensive axillary lymph node surgery (see below). It is also frequently used in evaluating patients with melanoma.
What is the lymphatic drainage?
Lymphatic system refers to a collection of vessels that, like the system of blood vessels, circulates fluid through the tissues in all parts of the body. The lymphatic drainage refers to the manner in which tissue fluid, or lymph, is drained from the body and returns to a central location -- in this case, a lymph node. The lymphatic fluid has a milky appearance.
Why do a sentinel node biopsy?
Sentinel node ("gland") biopsy is performed to examine the tissue of the node to learn whether that node does or does not have tumor cells within it. The biopsy is performed to verify if there are cancer cells present in the lymph node. This procedure helps the surgeon accurately stage the tumor. Staging a tumor refers to determining the extent to which it has spread in the body. A negative biopsy can avoid the removal of a large number of lymph nodes which can lead to lymphedema. Although lymphedema can be a complication of sentinel lymph node biopsies, it is much more common when multiple lymph nodes need to be removed.
How does a tumor spread?
Tumors have only four ways of spreading:
- by local invasion of adjacent tissue,
- by direct growth or extension into nearby tissues,
- through the blood stream, and
- through the lymphatic system.
Some tumors spread preferentially by the lymphatic system, meaning that the cancer cells tend to spread by this method.
How is it determined which is the sentinel node?
Which lymph nodes are the sentinel nodes for a given tumor is determined by injecting around the tumor a tracer substance that will travel through the lymphatic system to the first draining (sentinel) nodes and identify them. The tracer substance may be blue dye that can be visually tracked or a radioactive substance that can be detected as with a hand-held Geiger counter or both.
What types of specialists perform a sentinel lymph node biopsy?
Sentinel lymph node biopsy is performed by surgeons. This procedure is most commonly performed to evaluate breast cancers and melanomas, so breast surgeons often perform this procedure.
What happens during a sentinel lymph node biopsy?
After the tracer substance is injected, the surgeon identifies the sentinel lymph node and surgically removes it through a small incision. This may be done in an outpatient surgery center or a hospital operating room. Sentinel lymph node biopsy is often done at the same time as the removal of a primary tumor.
What does the sentinel lymph node biopsy show?
Biopsy of the sentinel lymph node can reveal whether there are or are not lymphatic metastases, which are cancer cells that have spread from the original primary tumor into the lymphatic drainage system. The sentinel node can be rapidly evaluated while the patient is still in surgery utilizing the technique of frozen section analysis. The final report on the sentinel node awaits the final analysis by the pathologist on what is called formalin fixed tissue.
If the sentinel node contains tumor cells, removal of more nodes in the area may be warranted. This may be done during the same procedure if the first sample is evaluated while the patient is still in the operating room. If the sentinel node is normal, it is unnecessary to remove many additional lymph nodes, such as the axillary lymph nodes (called an axillary lymph node dissection or ALND) in a patient with breast cancer.
What are the benefits of a sentinel lymph node biopsy?
The sentinel node biopsy allows the examination of one lymph node to first determine if a tumor has spread to the lymph nodes at all. If the sentinel node is negative for tumor cells, it is not necessary to surgically remove additional lymph nodes. The procedure helps certain patients avoid more extensive surgical procedures involving the removal of multiple lymph nodes, such as axillary lymph node dissection in patients with breast cancer. It means that the patient will not have to experience the side effects of a more extensive lymph node removal procedure, such as lymphedema (swelling) of the arm in patients who have had axillary node dissection. It can be performed in patients undergoing a mastectomy or lumpectomy for breast cancer.
What are the side effects and complications of a sentinel lymph node biopsy?
The most common side effects are short-term bruising, pain, or swelling at the biopsy site. As with any surgery, bleeding and infection are possible complications. Another possible risk is a false-negative result, which means that tumor cells are present but not detected by the procedure. Studies with breast cancer patients have shown false-negative rates of around 10%.
Is the use of the sentinel lymph node biopsy common?
Yes. Sentinel lymph node biopsy has, for example, become a standard technique for determining the nodal stage of the disease in some patients with malignant melanoma and with breast cancer. The use of sentinel node biopsy is still being investigated with other types of cancer such as colon cancer, stomach cancers, and others.
What is the recovery time after a sentinel lymph node biopsy?
The recovery time varies, depending on whether or not the sentinel node biopsy is associated with removal of the primary tumor and the extent of surgery required. In any case, sentinel lymph node biopsy offers a quicker recovery time than a more extensive lymph node dissection.
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What you should know about breast cancer
- Breast cancer is the most common cancer among American women.
- One in every eight women in the United States develops breast cancer.
- There are many types of breast cancer that differ in their capability of spreading (metastasize) to other body tissues.
- The causes of breast cancer are unknown, although medical professionals have identified a number of risk factors.
- There are 11 common types of breast cancer and 4 uncommon types of breast cancer.
- Breast cancer early signs and symptoms include
- a lump in the breast or armpit,
- bloody nipple discharge,
- inverted nipple,
- orange-peel texture or dimpling of the breast's skin (peau d'orange),
- breast pain or sore nipple,
- swollen lymph nodes in the neck or armpit, and
- a change in the size or shape of the breast or nipple.
- Breast cancer can also be symptom free, which makes following national screening recommendations an important practice.
- Breast cancer is diagnosed during a physical exam, by a self-exam of the breasts, mammography, ultrasound testing, and biopsy.
- Treatment of breast cancer depends on the type of cancer and its stage (0-IV) and may involve surgery, radiation, or chemotherapy.
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The symptoms and signs of serious health problems can be caused by strokes, heart attacks, cancers, reproductive problems in females (for example, cancers, fibroids, endometriosis, ovarian cysts, and sexually transmitted diseases or STDs), breast problems (for example, breast cancer and non-cancer related diseases), lung diseases (for example, chronic obstructive pulmonary disease or COPD, lung cancer, emphysema, and asthma), stomach or digestive diseases (for example, cancers, gallbladder, liver, and pancreatic diseases, ulcerative colitis, or Crohn's disease), bladder problems (for example, urinary incontinence, and kidney infections), skin cancer, muscle and joint problems, emotional problems or mental illness (for example, postpartum depression, major depression, post-traumatic stress disorder (PTSD), mania, and schizophrenia), and headache disorders (for example, migraines, or "the worst headache of your life), and eating disorders and weight problems (for example, anorexia or bulimia).
Breast Cancer Treatment by Stage
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- hormone therapy,
- radiation therapy,
- HER2-targeted therapy,
- neoadjuvant therapy, and
- adjuvant therapy.
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What Is the Sentinel Lymph Node in Breast Cancer?The first nodes in the axilla affected by breast cancer are known as sentinel or guardian lymph nodes. A positive sentinel lymph node biopsy or SLNB indicates that the cancer is no longer in situ.