lymphedema prevented by reverse axillary mapping !!!

[Lani]

from ASCO Breast:

Axillary Reverse Mapping Limits Lymphedema After Breast Cancer Surgery
Oct 06 - In patients undergoing surgery for breast cancer, axillary reverse mapping - identifying and preserving the lymphatics draining the arm - can cut down rates of lymphedema, according to data presented this week at the ASCO 2010 Breast Cancer Symposium in Washington, DC.

In fact, for patients undergoing sentinel lymph node (SNL) biopsy only, the lymphedema rate after axillary reverse mapping was less than 2%. The rate was 24% for patients who underwent axillary lymph node dissection (ALND). Out of 95 cases, only one node identified by axillary reverse mapping was malignant.

Earlier estimates put the rate of lymphedema following breast cancer surgery as high as 50%, depending on the extent of surgery.

Before the work by investigators at the University of Arkansas for Medical Sciences in Little Rock, "we knew that lymphatic drainage from the arm and the breast eventually joined together," lead author Dr. Cristiano Boneti told Reuters Health, "but no one knew at what level, by what pathway, or how they varied from one person to another."

They found that about a third of patients have lymph nodes from the arm in close proximity to, but still separate from, those draining the breast. So long as they mapped both, they could safely sample nodes from breast without harming nodes from the arm.

Their study involved 95 patients who underwent SLN biopsy, including 21 who also had ALND, between 2007 and 2009. Thirty-two patients also had radiation therapy.

After localizing the SLN with radioactive tracer, the surgeons injected a blue dye (lymphazurin) under the skin of the inner arm on the ipsilateral side to evaluate fluid drainage through the arm's lymph node system.

Nodes draining the arm were preserved in all but six cases (94%). As a result, lymphedema was limited to one of 74 patients (1.4%) with SLN alone and five of 21 who had ALND (24%).

Of the six arm nodes resected, three were due to crossover of arm and breast lymphatics and two were due to their proximity to the SLN. Only one had grossly metastatic involvement, which the authors note in their abstract was in a heavily positive axilla with more than 10 positive nodes.

"When there's any overlap (of lymph nodes) or clinically significant disease, even nodes draining the arm need to be removed," Dr. Boneti said. He has found that this accounts for about 20% of breast cancer patients undergoing surgery.

"But if the patient has minimal disease, it's safe to leave the blue node behind."

To determine which patients benefit the most from preserving the lymphatics of the upper extremity, Dr. Boneti and colleagues have started a phase II, prospective trial of axillary reverse mapping.