What is a sentinel lymph node?
The sentinel nodes are the first lymph nodes to which cancer cells are most likely to spread from a primary tumor. Breast cancer usually spreads first to the lymph nodes in the axilla (armpit). These sentinel lymph nodes are the first to drain the lymphatic fluid from the breast and to spread cancer if it is contained within the fluid.
What is Sentinel Lymph Node Biopsy (SLNB)?
A sentinel lymph node biopsy (SLNB) is a procedure in which the sentinel lymph nodes are identified, removed, and sent for pathological examination to detect the presence of cancer cells. It is thought that if breast cancer cells were to escape into the lymphatic system, they would travel to the sentinel nodes before moving on to other nodes. Sentinel lymph node (SLN) technique is based upon the study that tumor cells migrating from a primary tumor invade one or a few lymph nodes before involving other lymph nodes.
SLNB is a minimally invasive technique and is proven to be a reliable and accurate alternative treatment modality for breast cancer patients. During a sentinel lymph node biopsy, the surgeon removes only a few (1-5) sentinel lymph nodes.
Dissection of the sentinel nodes reduces the possibility of complications and in most cases provides the necessary information about the cancer. If the sentinel nodes are free of cancer, it is assumed that the remaining nodes are also clear and no further lymph nodes are then removed.
What are Lymph Glands/Nodes?
The lymphatic system is a structure of lymph vessels and lymph glands throughout the body which play an important role in the body’s mechanism of fighting infections and tumors. Tiny channels carry fluid and debris to the lymph nodes/glands which act as filters. Groups of lymph nodes are located in the neck, underarms, chest, abdomen, and groin. The lymph nodes that filter waste fluid and cells from the breast are mainly located in the armpit (also called the axilla.) These lymph nodes are usually the first ones affected if cancer spreads beyond the breast. The number of lymph nodes in the axilla varies from person to person but usually ranges from around 20 to 40.
Why is it important to know whether tumor cells are present in the glands under the arm?
The status of the axillary lymph nodes is one of the most important predictive factors in women with early stage breast cancer. The axilla must be explored surgically and some lymph nodes removed and sent for pathological examination. Pathological examination of lymph nodes is the most accurate method for assessing spread of disease to these nodes. The treatment plan of breast cancer is based on whether the lymph glands contain tumor cells.
Surgery (lumpectomy or mastectomy) in conjunction with axillary dissection/clearance is the best treatment option to remove the breast tumor. A significant number of lymph nodes are removed during the surgery. Lymphedema (localized fluid retention and tissue swelling) is a possible complication associated with the procedure.
How are the sentinel lymph node identified?
The following guides the surgeon to identify the sentinel lymph nodes:
Does Sentinel Node Biopsy indicate whether I should undergo a Lumpectomy or a Mastectomy?
Sentinel node biopsy will not affect whether your tumor is suitable for lumpectomy (wide local excision) or mastectomy.
When is sentinel node biopsy performed?
Sentinel node biopsy is usually performed along with breast surgeries. Rarely, it is done as a separate procedure before mastectomy when immediate reconstruction is preferred. A final pathological report of the sentinel nodes allows for a complete axillary clearance at the time of breast surgery/reconstruction. Based on the status of the sentinel nodes, one can decide about the post-surgery radiation which in turn influences reconstruction decision.
What is a false-negative result?
In some patients, the cancer cells are not seen in the sentinel lymph nodes although they are present and may have already spread to other regional lymph nodes or other parts of the body. A false-negative biopsy result gives the patient and the doctor a false sense of security about the extent of cancer in the patient’s body.
False-negative SNB results may harm the treatment outcome for various reasons: missed nodes might lead to axillary recurrence that can be difficult to treat, diseased axillary nodes may be a possible source of distant metastases, and under staging affects decisions about systemic and specific radiation therapy to the breast, chest wall and nodal basins.
Sometimes, cancer cells may block the lymphatic vessels running to the lymph nodes that contain cancer cells and result in a false-negative report. In this case, the radioactive substance flows and stains the normal lymph nodes. A false-negative result can be avoided by removing the abnormal palpable nodes (not stained) during the surgery.
Multiple sentinel nodes are present in most breast cancer patients, and it is now accepted that cancer cells often drain directly to a group of nodes rather than to a single node.
Removal of sentinel lymph nodes is based on cherry-picking phenomenon leaving the axillary lymphatics in areas away from the sentinel nodes.
Mastectomy is a surgery to remove the breast, usually performed to treat or prevent breast cancer. There are 4 main types of mastectomy depending on the stage of cancer, size of the breast tumor and lymph node involvement:
Mastectomy is recommended when your breast is affected with cancer or you have a high risk of developing breast cancer. Total mastectomy is usually indicated for patients with noninvasive breast cancer, Paget’s disease of the breast, or recurrent breast cancer.
Modified radical mastectomy is usually indicated for patients with early-stage breast cancer, locally advanced breast cancer (to shrink the tumor after chemotherapy), inflammatory breast cancer (mostly after chemotherapy), or Paget’s disease of the breast.
Prior to your surgery, your nurse or surgeon will mark the area where the cut will be made. The procedure is performed under general anesthesia. The surgeon will make an oval shaped incision around the nipple, across the breadth of the breast. Depending on the type of mastectomy, the breast tissue underlying the skin will be removed, along with lymph nodes and the inner layer of muscle tissue. The surgeon will then insert surgical drains, (tubes to collect excess fluid) and close the incision.
If you choose to rebuild your breasts after mastectomy, your plastic surgeon will perform a surgery called breast reconstruction. During reconstruction, your surgeon creates a breast mound using an implant or tissue flap taken from your stomach, thighs, back, or buttocks. The reconstructive surgery can be done during or after mastectomy.
This surgery will require you to stay in the hospital for about 3 days or a little longer if you have opted for immediate reconstruction. After discharge, you will be given instructions on how to care for the surgical drain, bandage and stitches. In order to avoid stiffness and scar formation, you will have to follow some simple hand exercise regimes. Your surgeon will also recommend the appropriate time for you to start wearing a bra or prosthesis.
If you do not develop any complications from the surgery, you can resume physical activities within 6 to 8 weeks.
You may experience sensation or pain in the breast that has been removed (phantom pain) over a period of months after surgery. Pain medications can be used to treat this type of pain.
Risks and complications
Mastectomy procedures are usually safe, but may involve the risk of infection, bleeding, pain, swelling in your arm, hard scar tissue formation at the site of surgery, shoulder pain and stiffness, numbness (especially under your arm), and accumulation of blood in the surgical site.