Sentinel Lymph Nodes

[delby]

I was dx w/invasive lobular, 2 cm, with 4 sentinel nodes positive and no vascular invasion.  Is there a difference w/ these nodes being positive vs. the axilliary nodes being positive? In other words, if you have positive nodes...are these nodes the better ones as they are considered "the first line of defense"?  I would appreciate some clarification as I'm getting different opinions on this.  

Thanks,

Delby

[CCF-RN,MSN-rf]

Dear delby: Part of the surgical staging of invasive breast cancer includes an evaluation of the lymph nodes under the arm called axillary lymph nodes.  An axillary dissection involves removal of a number of lymph nodes under the arm and these lymph nodes are then evaluated by a pathologist for any evidence of cancer involvement.  With a sentinel lymph node biopsy, usually a blue dye and a radioactive tracer are injected into the breast and are expected to travel through the lymphatic channels into the specific lymph nodes draining the breast.  The lymph nodes that take up blue dye or the radioactive tracer (as well as any suspicious appearing lymph nodes) are felt to be the most likely to contain cancer if there is any cancer in the lymph nodes.  Sentinel lymph nodes are usually evaluated more closely by the pathologist with special stains and may pick up tumor cells which could have been missed with routine staining.  If the sentinel lymph nodes are negative for tumor, there is a high likelihood that the remaining lymph nodes that were not removed are also free of cancer.  When the sentinel lymph nodes are involved, a full axillary dissection is frequently performed.  The total number of lymph nodes involved is a more important prognostic factor than whether the lymph nodes were found with a sentinel lymph node procedure or with a full axillary dissection.  One exception may be when a sentinel lymph node has only a few cancerous cells identified only with the special stains but not picked up with routine staining.  This type of micrometastasis may have a better prognosis than other lymph node metastases.

[surgeon]

the concept of sentinal nodes is not so much about "first line of defense" as about those to which spread is most likely to occur, if it occurs. So the taking of sentinal nodes is to be able to avoid complete axillary dissection for the situation where no nodes are involved. If they are involved, the significance is that spread has occcured and chemo is necessary. There are some relative differences regarding number of nodes involved; the more nodes, the more dangerous -- although that's a relatively less significant concept than the fact of involvement per se. Some people still feel that if the sentinal nodes are involved, the axillary dissection should be completed to see how many more are involved, if any, and to remove other deposits of tumor. That has become more controversial of late.

[delby]

Thanks for your response, however, I'm not sure you understood my question or that I made myself clear.  Is there a difference between the 2 types of nodes (sentinel and auxilliary)?? The cancer, as I understand it, travels from the tumor site to the sentinel nodes and if positive,  then to the auxilliary nodes. Are positive sentinel nodes, of which I had 4, with no auxilliary involvement, a better case scenario (if there is such a thing) than having 1 positive sentinel and 3 positive auxilliary nodes. I keep thinking in my mind that the sentinel nodes are the first line and the auxilliary nodes as being the next line of defense.  I would appreciate your views on this.  Thanks again.

[surgeon]

the term is axillary, not auxillary. It's the term for the nodes in the underarm. The sentinal nodes are among the axillary nodes. It's the term for those nodes that light up when dye is injected near the tumor, meaning they are the ones most likely to have tumor in them if the tumor has spread. There is no significance other than that. I guess my original answer was too obscure. No, there is no difference. Sentinal nodes are, in the case of breast cancer, axillary nodes. The significance has to do with whether or not the cancer has spread to axillary nodes, not which of the nodes to which it's spread. And, as I said, there may be some significance to how many nodes are involved, which can't be fully determined by sentinal node sampling alone.