Sentinel Node Biopsy

The first potential place that breast cancer cells can spread to is the lymph glands under the axilla (armpit). Traditionally most of the lymph glands were removed as part of the first breast cancer operation in order to:

1. Identify lymph glands that are involved which can determine whether other treatments (e.g chemotherapy) are needed
2. Remove any cancerous lymph nodes
3. Prevent cancer spreading to the lymph glands in the future

Sentinel node biopsy is a reliable and safe technique that avoids most of the complications and morbidity associated with traditional axillary surgery (e.g lymphodema). Surgeons performing this technique undertake specific training and accreditation.

How is it performed?

By using a safe radioactive tracer, it is possible to identify the sentinel or “gatekeeper’ lymph node(s) to assess whether the cancer cells have spread to the axilla.

Not all patients are suitable for this technique (for example those with large tumours or those that have enlarged glands on their initial assessment).

What if the sentinel node is positive for cancer?

In the event of the sentinel node being “positive” for cancer, not all patients require further operations. If the deposit of cancer in the lymph node is very small (known as a micrometastasis) then no further surgery is required. If it is bigger than 2mm (known as a macrometastasis) then you may require a second operation to take more lymph nodes. In some patients radiotherapy is used instead of further surgery. All decisions regarding your individual treatment are made by a Multidiscilinary Team where representatives from all the specialities (Surgeons, Oncologists, Pathologists, Radiologists, Nurse Specialists) collectively decide the best treatment plan for you, depending on the specific features of your cancer. 

Are there any risks with the procedure?

In addition like every test in medicine it has a small false negative rate (around 5%). A false negative result is where the lymph node looks normal but there is cancer cells in a lymph node nearby. That is why patients are carefully selected for this technique. Some patients will have a clip placed to mark a postive lymph node to make sure the correct node is removed at surgery. This is important if, for example, you have chemotherapy first where the postive lymph node can become "negative" during treatment.