Is Axillary Disection Necessary if Sentinel Node Positive?

[azdb]

My wife had a lumpectomy and sentinel node biopsy in late May.  The breast tumor was infiltrating ductal carcinoma, less than 1cm, estrgogen neg, her 2 neu +, diploid, grade 2.  The tumor in the sentinel node is less than .1cm and confined by the lymph node capsule.   Two nodes were taken, the 2nd was unremarkable.  Since the sentinel node is positve, she is going to undergo chemo in additon to the radiation.  Is there any compelling reason to take out any more lymph nodes?  Since chemo is already in the game plan, what good can come from an axillary node disection?

[CCF-RN,MSN-rf]

Dear azdb:  Sentinel lymph node biopsy has not yet proven to be as accurate as lymph node dissection due to a phenomenon called "skip metastasis."  skip metastasis is when the first or second lymph node may be negative and a lymph node that is further up the chain may be positive. It is for this reason that lymph node dissections, rather than exclusive sentinel lymph node biopsies are recommended in many institutions.  The purpose of removing the lymph nodes is to plan treatment and provide information to help with staging and prognosis.  In your wife's situation, one could argue that the treatment may be unchanged regardless of whether more lymph nodes are discovered to be positive - and, therefore, there may not be a reason to remove more lymph nodes.  On the other hand, without removing more lymph nodes, you do not know if any more are involved, so staging and prognostic information may not be as accurate.  Is this information worth another surgery?  It merits a discussion of pro's and con's.  There may not be a "compelling enough" reason to further delay therapy by doing another surgery.

[surgeon]

It's an excellent question, and one to which there is not a scientifically good answer at the present time. The question is whether it increases cure to remove any nodes in which there might be residual cancer cells. Until recently, it's been standard practice to remove them if the sentinel node is positive because the good data for survival have all been in people who've had that done in the days before sentinel node biopsy. It's only in the very recent months that people are talking about the necessity of doing it, and organizing studies to test it. Intuitively, what you say about chemo makes sense: if it works, what difference would it make to remove a few extra cells....One issue is this: chemo doesn't always work. Theoretically, there are some women whose only residual cancer cells after surgery are in a couple of lymph nodes, and theoretically some of them would and some of them wouldn't be killed by chemo. So there might be some women who would miss their chance for cure if those few cells were left behind. Theoretically. But the fact is we don't know if that's true, and if so how to identify those in whom the treatments would or wouldn't make a difference. At this time in our understanding (or lack thereof) it's generally considered standard of care to complete the axillary dissection. Based on incomplete evidence.