Breast Cancer and Axillary Lymph Node Dissection
If you’ve been diagnosed with breast cancer that has spread to multiple lymph nodes, your surgeon may need to remove additional lymph nodes from your underarm area. This surgery is called an axillary lymph node dissection.
Unlike a sentinel lymph node biopsy, during which three or fewer lymph nodes are removed, an axillary lymph node dissection involves the removal of more than 10 lymph nodes.
An axillary lymph node dissection can be done when a lumpectomy or mastectomy takes place, or as a separate surgery (called a lymphadenectomy).
What are axillary lymph nodes?
Lymph nodes help the immune system by filtering out viruses, bacteria, and other waste from the body. Lymph fluid from the breast and other nearby tissues drains into lymph nodes located in the underarm, also called the axilla area.
There are three levels of axillary lymph nodes:
level I or low axilla, in the lower part of the armpit
level II or mid-axilla, in the middle part of the armpit
level III or upper axilla, in the upper part of the armpit
If cancer cells break free from a tumor in the breast, they often travel first to level I lymph nodes, then to level II lymph nodes, and sometimes to level III lymph nodes. Typically only level I and II axillary lymph nodes are removed during axillary lymph node dissection.
Why axillary lymph node dissection is done
The removal of lymph nodes from your underarm or armpit area can help your doctors determine the chance that breast cancer has spread (metastasized) to other areas of the body. If these lymph nodes contain cancer, removing them may also reduce the risk of the breast cancer coming back (called recurrence).
Once axillary lymph nodes are removed and checked for cancer, surgeons can determine:
whether you need additional imaging tests
what your best treatment options are
Is axillary lymph node removal right for me?
Axillary lymph node removal surgery may not be necessary for some people with breast cancer. Surgeons usually recommend axillary lymph node dissection if:
the cancer is larger than 5 centimeters
imaging or needle biopsy results show cancer cells in multiple lymph nodes
sentinel lymph node biopsy results show cancer cells in three or more lymph nodes
sentinel lymph node biopsy results still show cancer cells in the lymph nodes after chemotherapy but before breast surgery
there are cancer cells in more than two lymph nodes and after mastectomy, the treatment plan does not include radiation therapy
Axillary lymph node dissection is not recommended if:
you’ve been diagnosed with early-stage breast cancer, there are cancer cells in only one or two sentinel lymph nodes, and you’re having lumpectomy with radiation
your cancer care team recommends radiation therapy instead of axillary lymph node dissection to treat any cancer remaining in the lymph nodes
What to expect during axillary lymph node dissection
During an axillary lymph node dissection, you’ll be under general anesthesia. The surgeon will make a two- to three-inch incision under your arm and take out level I and level II lymph nodes. Surgeons do not typically remove level III lymph nodes unless there is evidence that cancer has already spread to them. Still, some surgeons may take out one or two level III nodes as an extra precaution. They will send the removed nodes to a pathologist to check for cancer cells.
If you’re having the procedure at the same time as breast cancer surgery, your surgeon may be able to remove the lymph nodes and the cancer through the same incision, depending on how close the breast cancer is to the armpit.
Before closing the incision, the surgeon will place a small tube (called a drain) in the area where they removed the lymph nodes and attach a drainage bag to the end of the tube to collect fluid. The bag remains in place for a few weeks or until no more fluid is draining.
Because axillary lymph node dissection involves the removal of 10 or more lymph nodes, there are greater chances of complications than with sentinel lymph node biopsy. These complications can include lymphedema, infection, and more.
What happens if an axillary node dissection is positive?
The greater the number of axillary nodes that are positive for cancer cells, the greater the chance that breast cancer has spread to other areas of the body. The number of lymph nodes that have cancer cells present also helps doctors to stage breast cancer. Knowing the number of positive axillary nodes you have will help determine the next steps in your treatment. This information can be found in your pathology report.
If multiple nodes are positive, the next steps for treatment may include additional imaging, tests, and radiation treatment to the lymph nodes, as well as hormonal therapy, targeted therapy, chemotherapy, or a combination of all of these treatments after breast cancer surgery.
Questions to ask your surgeon
Some people may find it helpful to ask the following questions:
How frequently do you perform this type of surgery?
Is axillary lymph node dissection my only option? Why do you recommend axillary node dissection instead of radiation therapy to the lymph node area?
Is it possible to try chemotherapy before surgery to see if I might have a sentinel lymph node biopsy instead?
Do you plan to remove level I, level II, and level III lymph nodes? Why?
Is there anything I can do to help prevent the side effects of axillary lymph node dissection? Is there a breast cancer rehabilitation specialist you can refer me to?
— Last updated on July 30, 2025 at 3:24 PM