Update on management of the axilla

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Published: 14 Dec 2015
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Dr Terry Mamounas - UF Health Cancer Center, Orlando, USA

Dr Mamounas talks to ecancertv at SABCS 2015 about the optimal surgical management of the axilla and how sentinel lymph node biopsy (SLNB) has increasingly become the standard of care over complete axillary lymph node dissection (ALND), even in some node-positive patients.

There has been significant evolution during the past 20 years, he notes in the interview. This started with the recognition of the importance of the sentinel lymph node (SLN) concept and it becoming an established method used for cancer staging. This challenged a century-old concept of complete removal of the axillary lymph nodes and meant that complete dissection was not always necessary. This had the advantage of reducing the side effects seen with complete dissection such as lymphedema, numbness and tingling.

Dr Mamounas explains that if the SLNB is negative then ALND is not performed. The use of the biopsy has been extended to include patients who present with clinically (or biopsy proven) involvement of the axillary nodes. If the SLNB is clinically node-negative after neoadjuvant chemotherapy then complete axillary dissection is not performed.

Provided that certain procedures are followed (removal of three or more SLNs, dual-agent lymphatic mapping, localization and removal of previously biopsied positive nodes and even the use of immunohistochemistry in the SLN evaluation), the false-negative rate of SLNB drops to below 10%.

Adoption of this approach has the potential to further decrease the use of ALND in patients who present with documented axillary lymph node involvement, Dr Mamounas says.

ecancer's filming at SABCS 2015 has been kindly supported by Novartis through the ECMS Foundation. ecancer is editorially independent and there is no influence over content.

You’ve been talking about sentinel node biopsy and management of the axilla, where do we stand? Why is this a crucial issue right now?

Over the last almost twenty years there has been a significant evolution in how we assess the axilla. We went from axillary dissection, which has significant comorbidity in terms of lymphedema and arm numbness and tingling, to a much less invasive procedure which is called sentinel lymph node biopsy. The idea behind the sentinel lymph node biopsy is to identify a few nodes or node that drain primarily the breast and remove that node to get the same information that we get with an axillary dissection.

And what’s your assessment of how well this is going?

It is going very well over the last twenty years, it has become the standard of care for patients with negative sentinel nodes. So if we remove the sentinel node and it’s negative we don’t dissect the axilla anymore. From then on we actually have expanded the use of this now to even use it for patients with a limited number of positive sentinel nodes where we don’t dissect the rest of the axilla. Also we have made significant progress in assessing this in patients together with neoadjuvant chemotherapy so we can downstage the disease in the nodes and then perform the sentinel node after neoadjuvant chemotherapy.

Of course you lose some information by going for sentinel node therapy, don’t you?

You may lose some information, particularly if the nodes are positive but if the nodes are negative you really don’t because you expect that the remaining nodes are negative as well.

So what’s your analysis of what the pluses are and what doctors need to be doing now?

The pluses are significant reduction in morbidity and we see much less rates of lymphedema, less arm numbness, arm dysfunction and we get essentially the same information. So this has been uniformly adopted now throughout the world as the standard of care for node negative patients and, again, in selected node positive patients as well.

What, then, are the controversial issues in this?

The controversial issue is that the procedure has as small false negative rate. In other words when you take the sentinel node out there is a small possibility that you will declare the sentinel node to be negative but other nodes left behind may be positive. Those rates are about 5-10%, depending on the circumstance, but because patients present with less and less risk of involvement of the axilla when you multiply these two numbers, you’re left with a very small number where you leave disease behind. The clinical data suggests that even if that happens it doesn’t affect disease free or overall survival. In other words, it is as safe a procedure as the extensive axillary dissection that was done before because the rates of local recurrence in the axilla are very, very low with sentinel lymph node biopsy.

So what messages do you think doctors need to absorb from what we now know about the use of sentinel node?

The main message is that it has been now a standard of care that we’ve demonstrated through many randomised clinical trials for node negative patients but now it has a place in node positive patients. By using the sentinel lymph node biopsy and selectively radiotherapy for some patients with positive sentinel nodes we can actually avoid complete axillary dissection in the majority of the patients because what we have found also through clinical trials is that if you do a sentinel lymph node biopsy, even if the nodes are positive and you don’t dissect the axilla and give radiotherapy to the axilla versus if you dissect the axilla, the morbidity from radiotherapy is less than the morbidity from an axillary dissection. So the take home message is that axillary dissection is going to go by the wayside in the not too distant future by finding all these different ways of approaching the sentinel node and thus not necessitating an axillary dissection.

And many people won’t be sad to see it go.

No, absolutely not because it’s a procedure that’s associated with significant comorbidity.