Sentinel lymph node biopsy linked to rise in micrometastatic breast cancer

[Hopeful]

http://www.breastcancersource.com/br..._27833___.aspx

The inference I make from this article is that SNLB is associated with much more detailed pathology of the node extracted; use of IHC and "breadloafing" to check for mets rather than just gross examination of the nodes. It also raises the question, I think, about stats from an era that predate the standard use of SLNB - were a substantial number of patients counted as node negative really node positive, thus unfavorably skewing the demographic and the stats based on it? As someone node negative following SLNB, I like to think so!

Hopeful

Your inference makes sense; I wonder if the study itself comes to any conclusions as to why. Or does it just provide the data and let others draw their own conclusions. What, by the way, is "breadloafing?" Thanks.

[Becky]

At surgery, I was deemed node negative but “breadloafing” (which is slicing the node in thin layers and examining each layer) found 2 micromets to the sentinel node. During SNB, 3 nodes were taken but I had to go back into surgery 2 weeks later because of the “new” nodal status because to be sure, protocol says 7 must be taken. Since the nodes are embedded in fat, a surgeon really can’t “count” so the second surgery took another 7. Only that first one had a bit of cancer in it. So, even though I ended up being devastated to have a positive node when told a week later, I am glad it was found because it changed my potential treatment from 4 dense dose AC to adding another 4 dense dose taxol. Then 4 months later, I was able to start the Herceptin after the trial results were released. If I were node negative (but not really node negative), no taxol and I would have probably had a problem getting Herceptin so soon after the 2005 ASCO meeting.

Hopeful – you are right about old stats though. Women who really weren’t node negative would not get all the treatment they required (as in my example) and would tend to recur more readily.

Thanks, Becky, for explanation. I'm pretty sure my pathology report (have to get it out) says that IHC was used on nodes--does IHC always include "breadloafing?" And is seven the protocol when a positive node is discovered? I had three nodes removed, two were sentinel nodes and the third was enlarged. Actually, they were all somewhat enlarged but no cancer was found. A bit late in the day to be asking this I guess, since my surgery was July 13, 2006.

[Hopeful]

Grace,

I followed the link to the abstract at the bottom of the article in my link above, and discovered that the full text of the article is available for free: http://jnci.oxfordjournals.org/cgi/c...ull/99/13/1044.

An interesting quote:

"SLNB, used in preference to ALND, may be the cause of a stage<SUP> </SUP>migratory or "Will Rogers" effect (12,36,38). For example, if<SUP> </SUP>SLNB reveals micrometastatic lymph node foci, stage IIA disease<SUP> </SUP>(T2N0—tumors sized 2–5 cm with no disease in the<SUP> </SUP>lymph nodes [N0]) could become stage IIB (T2N1—tumors<SUP> </SUP>sized 2–5 cm with one positive, micrometastatic lymph<SUP> </SUP>node). Thus, before the advent of SLNB, stage II node-positive<SUP> </SUP>breast cancers may have been considered to be stage I, node-negative<SUP> </SUP>disease. Our findings may reflect the impact of such upstaging<SUP> </SUP>on breast cancer incidence rates."

They go on to say that the method used to identify the micro mets (i.e., E&H with IHC) did not add to the stage migratory effect. However, this is in conjunction with SLNB, where we are still talking about microscopic examination vs. gross examination of the node, so it does not, to me, discount the statement in the paragraph above.

Otherwise, they don't really offer an explanation, that I can see. They conclude, "While the use of SLNB<SUP> </SUP>in community practice continues to increase, it is expected<SUP> </SUP>that cases with lymph node metastases also will continue to<SUP> </SUP>increase," which, I think, is consistent with the basic premise of micro vs. macro examination of the nodes.

Hope this helps,

Hopeful

[Hopeful]

Grace, I was planning to post this link at some point, and this looks like the right opportunity: http://breast-cancer-research.com/content/9/4/R40, based on your last question about node enlargement. Follow the link and then click on the provisional pdf link to see the entire article, with the formidable title, "Accuracy of computed tomography perfusion in assessing metastatic involvement of enlarged axillary lymph nodes in patients with breast cancer." (It is easier reading than it sounds!) One of the things that came up was that not all enlarged nodes were enlarged due to metastasis - some were enlarged due to inflammation.

Hopeful

[Jean]

Hopeful and Becky,
As always thank you for opening a informative discussion.
I remember when in my early days of the blur of dx with bc.
when I met with my breast surgeon, he informed how very
important this procedure was and even with my size tumor
to have it done. I was shopping for surgeons at the time.
He was at that time 3/05 one of the surgeons who had did
SNB as a regular part of all his procedures. No matter what
size tumor. For this I am thankful.

I remember asking him just how the testing was performed.
I was impressed with the details.

Great Article!
Jean

Thanks Hopeful,

I read the article and see that 8 had inflamed nodes, as was the case with mine. My second opinion (ultimately my surgeon) thought my cancer was IDC, about 2 cm, she said, although my initial biopsy said DCIS. I believe she was fooled by my nodes, which she kept going back to during my only examination prior to surgery. My lump was found by me (hardly a lump, more like an increase in previously diagnosed cystic breast tootsie roll) and was not visible on any scan other than MRI.

I still wonder if the three nodes were sliced--is that a requisite for SNB IHC pathology report? I hope so. I didn't have much faith in my pathologist as he never gave the size of DCIS in pathology report; my radiologist and I had to keep after him to get size. I also had to keep asking to get margin sizes, which were very large, one was 5 cm from the cancer.

Any idea why inflamed nodes? Surgeon and pathologist blamed it on initial fine needle biopsy, but that was so distant from nodes and a full month prior to surgery.

Thanks always for education.

[Hopeful]

Grace,

I am basing my comments on "breadloafing" on the discussion I had with the first of three radiation oncologists I interviewed, after my lumpectomy and before my re-excison SLNB. She told me that the standard for examination of the SLN was the thin slicing and staining. She explained how the technique was able to produce highly reliable pathological information. She left me with the impression that the thin slicing was SOP for SLNB; since only one node (or two) was removed, they look it over much more carefully, and are likely to find cancer cells that were overlooked when the nodes were sliced in half and visually inspected to determine positivity.

In the second lymph node article I posted, the authors reference a paper which found that "inflammation of the intestinal wall is characterized by higher perfusion parameters than normal tissue, but lower than neoplastic tissue," i.e., higher perfusion than normal but less than cancer, and try to relate that finding to the results of their own study. They theorize that "increased perfusion and permeability of inflamed tissue may be due to the effect of cytokines, that provokes vasodialation," i.e., that the inflammation causes the blood vessels in the tissue to expand, which causes an apparent increase in volume in the node. The purpose of the study on which the paper was written was to see if positive nodes could be identified by means of computer tomography measuring blood flow. They don't explain how the inflamed nodes got that way; they just described their findings in terms of measuring blood flow. Reading the description, it seems to parallel the "atypical hyperplasia" scenario in bc where the hyperplasia is a precancerous change. Angiogenisis was a topic covered in the lymph node paper; it seems the atypical tissue also develops atypical blood flow which could be a precurser to cancer cells growing. Just my interpretation, here, nothing else.

Hopeful

[Mary Jo]

I, too, at the time of surgery was told my nodes were negative for cancer. I had sentinel node mapping done the day before my surgery and 2 nodes were removed at surgery. After pathology went over the 2 nodes more thoroughly though 1 microscopic cell measuring .085 cm was found in the 1st node. The second node was clear. Because of the size and there being only 1 microscopic cell found I opted out of having more nodes removed even though protocol says you should have more removed. My surgeon and oncologist whole-heartily agreed with my decision. That being said I have always been a little bit thankful that 1 microscopic cell was found (although initially hearing about it made me sad) because if it hadn't been found I would not have had radiation because I had a mastectomy. Because we didn't go back in to remove more nodes my radiation oncologist recommended radiation. So the "pit" was radiated well as was the shoulder in the back - sternum area and breast area. I feel I now had a bit of added insurance I guess.

Thanks for all your information.

Mary Jo