Prophylactic Mastectomy... SNB necessary?

Shabby--in answer to your question: without biopsies (or mastectomies) we don't know. But as my surgeon said, we can't biopsy what we can't see. So I have to trust that if nothing suspicious shows up on my mammo, US, or MRI, then there's nothing more serious (DCIS or invasive ) going on. Some people might call that denial; I think that at some point you have to trust in your medical team and their knowledge/expertise. Some can't live worrying about it all the time so they chose PBMs. I'm not ready to go that route; but if I were to have something more serious show up (going for my MRI this Friday) I would seriously reconsider my options, including bilat masts.

anne 

Thank you for your clear explanation, Bessie.  You've taught me something new I didn't know about DCIS.  I guess I would have a question to Bessie: since they think that almost all ducts intertwine but don't intersect, does that mean that when you find widespread DCIS (for example requiring a mastectomy)  that they think the DCIS is occuring in multiple ducts?

The only thing I would change in the emphasis in Bessie's statement about LCIS, is that in a small (nobody wants to specify how small because there is not enough data) number of cases, they do think that LCIS actually does morph into invasive. 

For example, in this 2008 article, it says:

Out of a consecutive series of 88 LCIS,nine patients developed IBC (5 ILC and 4 invasive ductal carcinomas) between 2 and 10 years after initial biopsy. For each case, mitochondrial DNA heteroplasmy was analyzed in normal mammary gland epithelia, LCIS and IBC by PCR, direct DNA sequencing and phylogenetic tree clustering. Two cases of LCIS and ILC showed identical patterns of heteroplasmy. In one further case, additional mtDNA mutations were present in the ILC following LCIS. The remaining two cases of ILC and all 4 IDC were clonally unrelated to the previously diagnosed LCIS. While the overall risk for the development of invasive breast cancer following LCIS is relatively low and the majority of cases are clonally unrelated, our data clearly show that some LCIS eventually do progress to ILC. Thus, LCIS represents both an indicator lesion for an increased risk of subsequent invasive breast cancer and in some cases a precursor of ILC. http://www.ncbi.nlm.nih.gov/pubmed/17380381  (emphasis mine)  So that means ,if I'm reading this right, up to 3 out of 9 cases, the invasive breast cancer did have some degree of genetic damage in common with the previously diagnosed LCIS. 

Still, the LCIS patients who go on to get ILC are much higher than in the general population.  In the general population, about 10-15% of breast cancers are ILC. In the LCIS population, of the LCIS women who go on to get invasive, roughly 40% go on to get ILC.  So, from what I understand, we have little idea how LCIS confers its increased breast cancer risk.

The number of cases in this study is waaay too low to estimate risk in the general population. 

In the case of PLCIS, there is even less data.  PLCIS was first described fairly recently (~ in the 1990s) vs classic LCIS (in the 1940s) vs DCIS (somewhere around 1900 give or take a decade.)  PLCIS is less frequent than LCIS, and probably some/many cases of PLCIS were diagnosed as DCIS, particularly before immunological tests (i.e. ER, PR, E-cadherin)  became available. 

This 2009 paper opines:

These data support the current notion that CLCIS <classic LCIS> alone is more of a risk factor than immediate precursor for invasive carcinoma as these lesions harbor fewer genetic changes and thus will require longer time for progression to invasion. However, apocrine PLCIS appears to be a genetically more advanced lesion, similar to CLCIS that has evolved to invasive carcinoma. These data also clearly show that although PLCIS demonstrates some features similar to high-grade DCIS, these lesions have less genomic alteration than high-grade DCIS. Overall, the aCGH profiling changes in PLCIS qualitatively resemble lobular carcinoma more closely than high-grade DCIS.   http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2783988/?tool=pubmed

Here is a link to a THEORETICAL pathway.  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2783988/figure/F6/  That does NOT mean they think most classic LCIS morphs into invasive  - they don't. There isn't much data out there. 

Thank you again Bessie.  I wish I had the gift of  clear communication that you have.

leaf-----I don't understand all the #s, p's and q's in that article, but the solid line indicating the "predominant" progression of LCIS to ILC is kind of distressing. (although intellectually it does make sense that would be the case).

anne 

leaf, your question, "since they think that almost all ducts intertwine but don't intersect, does that mean that when you find widespread DCIS (for example requiring a mastectomy) that they think the DCIS is occuring in multiple ducts?" is really interesting. I've tried to dig into this before but I couldn't find anything.  Best I could do was find articles that said something like "DCIS can affect only one duct or can affect multiple ducts".  Okay, but how? 

Searching over the past couple of days, I got a little further, but only a little. This time, I found this one article which raises the question:

"Duct anatomy is also relevant to the development of mammary intraepithelial neoplasia, including ductal and lobular carcinoma in situ (DCIS and LCIS) and their putative precursors. By definition, clonal expansion of such lesions must be confined to the branches of a single duct system. Extensive DCIS within a mastectomy is not uncommon in the practice of surgical pathology. Are these lesions present within a single duct system, or more than one? Details of duct anatomy bear directly on this question, which is important for the better understanding of mammary carcinogenesis" 

The article doesn't really answer the question but does say that in their one example, there was no overlap of the ductal territories (i.e. each ductal system within the breast was distinct with no intersection).  They caution however that their findings "should not be over-interpreted. We have only studied one breast in detail, and it would be imprudent to assume that duct growth occurs identically in all breasts. While ductal and lobular carcinoma in situ may occupy circumscribed volumes of breast tissue, reminiscent of the discrete catchment volumes we describe, this pattern is not always observed, and different patterns of breast duct development may occur in different women."

I found the information about the ductal system presented in this article to be really interesting. From the visuals (fascinating!) it appears that some duct territories are narrow and short while others fill the length of the breast and are quite wide.  And there is everything in between.

Three dimensional anatomy of complete duct systems in human breast: pathological and developmental implications 

This doesn't answer if a "breast full of DCIS" means that there was DCIS in more than one duct or if the DCIS happened to be in a duct that covered much of the area of the breast. In my case, my mammogram showed two distinct areas of calcifications, so I'm guessing that I had DCIS in two ducts. But who knows!

For what it's worth...the SNB is my one regret. The upside, waking up in recovery with the relief of getting the "all clear" on the nodes that were removed was huge.

The downsides, swelling in my upper arm on the left side and underarm that hurts. Going for lymphatic massage and looking at my arms every day to see how much more swollen and soggy one side looks versus the other. Constant worry that this condition could become worse over time if not properly managed and PRAYING that this edema is still my body healing. Hoping that I don't need to wear a sleeve. Worring about how much worse flying will make it. Not being able to walk in the 3-Day that I had signed myself up for to celebrate my recovery because the heat and the distance may be too much for my arm.

I had both breasts removed to eliminate the long term worry of cancer, and I am so thankful to have had that choice. But, now I live with the worry of LE...and I am not really a worrier. I am having a short surgery for something else next month and the drama around not getting an IV in either arm has been frustrating. I don't have any swelling on my right side, so why not use that? Well...why would I risk triggering something on that side too?

I'm still hopefull that this is part of my body healing. I am managing the swelling and pain quite well and doing most of what I did before. But, it IS painful and it IS real.

So...if I had it all to do over again I would have seriously talked with my docs more about if the SNB was really needed and what would have happened if I requested not to have them removed.

After 6 months of testing, I had my BMX last December.  Because of a suspicion of invasive cancer in my right breast, I agreed to a SNB on that side.  

My BS told me after surgery that he removed 4 SNs and all were clear.  

Imagine my surprise when I got my path report back and found that I had a total of 19 nodes removed from my right side, and 9 from my left!

I'm still questioning wth happened, but it appears that my nodes were entwined with my breast tissue, especially in the tail of the breast.  

I'm still numb under my arms and hate that I have to fear developing lymphedema for the rest of my life.  

Cats