Less invasive surgical technique 'safe and effective' for breast cancer patients
Surgery to remove the first group of lymph nodes under the arm (also known as the sentinel lymph nodes) is a safe, effective and less invasive alternative to removing all of the lymph nodes in most breast cancer patients, US scientists have found.
Axillary-lymph-node dissection (ALND) is a surgical technique used to determine whether cancer has spread beyond the breast and to improve the chances of survival.
The procedure involves the removal of all or most of the lymph nodes in the underarm region, but some patients experience nerve damage and reduced function in the arm and shoulder.
In contrast, sentinel-lymph-node surgery (SLN) only removes the sentinel nodes, which are the ones located closest to the breast.
SLN therefore does not remove as much tissue and tends to cause fewer unwanted side-effects.
A new study, published in the journal Lancet Oncology, has now shown that despite removing less tissue, this less-invasive technique is just as effective as more invasive ALND in most patients.
The US National Surgical Adjuvant Breast and Bowel Project (NSABP) recruited 5,611 women whose breast cancer did not appear to have already spread to their lymph nodes on physical examination.
Half of the women underwent ALND surgery to remove all of the lymph nodes in the underarm area, while the other half had SLN surgery to remove the sentinel lymph nodes alone.
Patients were then assessed every four to six months over the next eight years, on average, to see whether there were any differences in survival, disease-free survival or disease spread.
The researchers found no significant differences in these measures between the two groups.
Patients who underwent the less invasive SLN procedure were less likely to experience functional arm deficits, sensory problems or lymphoedema (chronic swelling of the arm).
The study authors concluded that, in patients with no sign of cancer in their sentinel lymph nodes, removal of these nodes alone provides the same survival advantage as removal of all of the nodes in the underarm area.
"SLN surgery alone with no further ALND is an appropriate, safe, and effective therapy for breast cancer patients with clinically negative lymph nodes," they wrote, adding that SLN surgery "represents the next major step in reducing the extent of surgical procedures to treat breast cancer".
Writing in an accompanying comment, John Benson from the Cambridge University Teaching Hospitals Trust said that the paper "vindicates contemporary practice of SLN biopsy and provides support for a reduction in extent of axillary surgery for most patients with breast cancer".
Liz Woolf, head of Cancer Research UK's patient information website CancerHelp UK, commented: "These results are good news for women needing treatment for early breast cancer. Although women should have their lymph nodes assessed for breast cancer spread, surgery to the armpit to determine this can result in long-term side-effects.
"This new technique will help doctors treat breast cancers according to whether the disease has spread, with fewer long-term side-effects for the patient."
- Krag DN et al,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 (2010) Lancet Onclogy DOI: 10.1016/S1470-2045(10)70207-2