Axillary lymph node dissection, or ALND, has often been the surgery chosen by practioners to curb growth of breast cancer in patients. However, a recent study based on surgical trials, and published Online First in The Lancet Oncology publication, notes that SLN (sentinel node surgery) has equal success and is also a safe and effective treatment. This procedure has comparative success rates in breast cancer patients with clinically negative lymph nodes. Alternative SLN surgery involves the removal of the first set of lymph nodes under the arm that cancer spreads to. The technique was designed to preserve tissue and minimise side-effects, but still achieve the same cancer control.

What is the ALND procedure exactly? It basically removes all the lymph nodes in the underarm region of a patient. Via this process, the cancer can be regionally controlled potentially and detect spreading. However as with any surgery there is a risk of bleeding, infection, and poor wound healing. Fluid or blood could accumulate around the breast or underarm area and require drainage. Numbness and tingling in the underarm and arm can occur due to nerves being cut during surgery. Most women get a significant amount of sensation back, but it may not be 100%. Muscle tightness of the underarm can occur, but this usually improves with time in most cases. Lymphedema, or swelling of the arm can occur weeks, months or years after surgery.

So how do SLN operations work? On the day of surgery (lumpectomy or mastectomy), patients are sent to the nuclear medicine department. A radiologist injects the patient with a small amount of radioactive substance around the area of the breast tumor. This usually is done several hours before surgery. The substance dye flows through your lymph ducts to your lymph nodes. Before surgery, a special blue dye is injected around the tumor. A small incision is made in the armpit. Then to identify the sentinel node, the path of the blue dye is tracked using a device that detects the radioactivity in the lymph nodes. The node or nodes which exhibit these features are removed in the operating room and sent to pathology for immediate evaluation.

The National Surgical Adjuvant Breast and Bowel Project (NSABP) B-32 trial was established to determine whether SLN surgery can achieve the same survival and regional control as ALND with fewer side effects.

Eighty centers and 5611 women with SLN-negative breast cancer in the USA and Canada were randomly assigned and placed into two groups. One group undergoing SLN surgery plus ALND and a SLN surgery alone group. Overall survival, disease-free survival, and regional control were reviewed at six month intervals over an eight year time period.

In conclusion, there were no significant differences in overall survival, disease-free survival, or regional control between the two groups.

Importantly, deficits in arm functionality, sensory problems and lymphoedema were all decreased in the SLN group. In SLN, as mentioned above, a blue die is used to detect radioactivity in the lymph nodes. Limited allergic reactions to the die occurred in 46 patients but were not severe.

The authors say:

The results from B-32 show that in the SLN-negative population, any survival advantage of full ALND is fully mitigated by simply removing the SLNs. SLN surgery alone with no further ALND is an appropriate, safe, and effective therapy for breast cancer patients with clinically negative lymph nodes..SLN surgery represents the next major step in reducing the extent of surgical procedures to treat breast cancer.

In support, John Benson from the Cambridge University Teaching Hospitals Trust, Cambridge, England states regarding this published report that it:

Vindicates contemporary practice of SLN biopsy and provides support for a reduction in extent of axillary surgery for most patients with breast cancer.

“Sentinel-lymph-node resection compared with conventional axillary-lymph-node dissection in clinically node-negative patients with breast cancer: overall survival findings from the NSABP B-32 randomised phase 3 trial”
Prof David N Krag MD, Prof Stewart J Anderson PhD, Thomas B Julian MD, Ann M Brown ScD, Seth P Harlow MD, Prof Joseph P Costantino DrPH, Prof Takamaru Ashikaga PhD, Prof Donald L Weaver MD, Prof Eleftherios P Mamounas MD, Lynne M Jalovec MD, Prof Thomas G Frazier MD, Prof R Dirk Noyes MD, Prof André Robidoux FRCSC, Hugh MC Scarth FRCSC, Prof Norman Wolmark MD
The Lancet Oncology, Early Online Publication, 21 September 2010
doi:10.1016/S1470-2045(10)70207-2

Written by: Sy Kraft, B.A. – Journalism – California State University, Northridge (CSUN)