Seninel node vs Axillary Dissection

[Sweetpea2000]

I reside in Canada where axillary dissection is still the norm. I have a 1.1cm X .8cm infiltrating duct carcinoma at 3o'clock on my left breast.  It was discovered on an ultrasound (negative on mammogram) and follow-up core biopsy. I have had a MRI which clarified that this is the only lump.

I will be having a lumpectamy on Tuesday.  My doctor asked me to participate in the B32, randomized Phase 3 clinical trial.  I am concerned about the after-effects of the more intrusive, Axillary dissection and since the study only gives me a 50% chance of having a Sentinel node dissection, I have opted out of the study and requested a Sentinel node dissection.  My surgeon has agreed to this, but is somewhat reluctant, as this method of treating cancer is still not the standard in Canada.  

I weighed my decision based on the following:  I was asked to be in the study, therefore, I must be at a lower risk; there is a 3 - 5% chance of a false negative (my greatest concern, although I don't really comprehend the implication of this); I have a fear of the intrusiveness of axillary dissection and the possibility of lymphademia.  How do I know whether I have made the right decision?  What risks should I weigh?  Have I considered the right decision making criteria in my decision?  What else should I consider?  Sentinal node dissection appears to be more common in the US.  What has led to the trust in this approach?

Many thanks!

[CCF-RN,MSN-rf]

Dear Sweetpea2000:  The sentinel node biopsy is fairly widely accepted in the U.S., in part because of the pressure of women who prefer this approach to axillary node dissection and in part due to clinical trial results.  In general, it is done in people who have, what are perceived to be, low risk tumors.  There is still concern among physicians about the incidence of "skip" metastasis, where the sentinel node is negative and the second or third node is positive.  The incidence is low, but in some cases, it could affect women getting appropriate therapy.  For example, if a tumor is very small (less than 1cm) chemotherapy may not be recommended if the sentinel node is negative.  If, there is a false negative result, that person should get chemotherapy but would not based on the SNB.

I have read Surgeon's comment and it states well the issues surrounding this decision, including the fact that axillary lymph node dissections are not what they used to be and the corresponding incidence of lymphadema is actually quite low with current techniques.  

Good luck in your decision.

[surgeon]

I'll chime in; please also note you'll get an official answer. SNB has become well-accepted in the US. In fact, the surgeon (Dr. Guiliano) who pioneered it for breast cancer and I trained together (many years ago!).The trust in the procedure derives from many studies at many medical centers across the country, involving tens of thousands of patients. There remain some issues; false negative being the main one. And it's somewhat experience-dependent. Most hospitals in which it's done require a period of study during which the surgeon first does SNB, and then proceeds at the same time with axillary dissection; this allows comparison of the accuracy of each surgeon's technique. In very experienced hands, the accuracy is said to be around 95%; which means "only" one in twenty women will get the wrong result. The significance of a wrong result would be if the woman were in the category, based on tumor criteria, wherein she'd not be getting chemo unless the nodes were involved, and she therefore failed to get needed treatment beacause the SNB missed the involved nodes. There also remains some controversy as to whether if the SNB is positive, completion axillary dissection should be bone: in other words, is there therapeutic value to removing nodes, or only diagnostic value. The answer is not absolutely clear. Lymphedema is unpleasant if it occurs. However, in the "old" days, we typically did a very thorought axillary cleanout, which left little alternative routes for lymph flow. Nowadays, most surgeons would do a limited dissection, leaving tissue at the top of the axilla for lymph flow; this especially would be done for a small tumor without grossly abnormal nodes at the time of dissection. When such a modified dissection is done, the chance of lymphedema is much reduced. How does one know if one is making the "right" decision? Really, one doesn't. If something bad is supposed to happen only 5% of the time, if one plays the odds clearly it's "right" to choose it. But if one turns out to be in the 5% instead of the 95%, does that make it "wrong?" We make such choices, in medicine, based on studies of large numbers of people. We'll be "right" in the majority of instances. In any procedure for any group of people, there will be people whose outcomes defy the odds, both better and worse than predicted. I think the way to decide derives from many factors: number one is hearing what your doctors recommend, asking probing questions about exactly why, and deciding to what extent the answers make sense to you. Ultimately it's a balance of your gut feelings about your doctors and yourself.

[czern]

I know of someone in a Charleston, WV trial who found a positive node even though the sentinel node was negative. It to me was not worth the chance. I am thankful that my surgeon took them all. Just really pray about it.

[heidiho]

SNB is also the standard at the medical center here in the Bronx, NY where I had lumpectomy (3.0), SNB & axillary dissection after showing one positive sentinel node (0.3 mm). Yet, I'm glad I had the whole AD...for peace of mind that the rest were clear.