Need help; really confused about margins

Thank you all so much for your support and Beesie and Redsox, especially, for your detailed analysis.  I will see the medical oncologist tomorrow and am already making up a list of questions for him, then the radiation oncologist next week.  In the meantime, I'm just stumped and my lack of understanding is contributing mightily to my anxiety.

The thing about the re-excision.  The BS didn't present it that it wasn't feasible, just that it wasn't necessary.  Thinking back on what he said, I'm wondering if what he meant was that even with a re-excision he would expect more "stray cells."  But if that is the case, maybe I should be thinking about a mastectomy?  The other thing that worries me about my report is that while the DCIS in the primary site (part A) is .7 cm the DCIS in the additional margin tissue is 1 cm.  So that sounds to me as though there is a lot more than just a cell or 2.  

 I just can't figure it out, and keep telling myself maybe there is something I am missing.  I don't believe the BS is incompetent; he came highly recommended to me by 5 different doctors. So I keep thinking there has to be something I'm not understanding.  Hence, a lot of anxiety in preparation to see the oncologist tomorrow.  I will definitely have my questions ready and will report back from the field!

I've been reading abstracts of results from the NSABP trials.  My oncologist gave me a summary of the studies on tamoxifen (NSABP B-24) and I looked to see what was there on margins.  Apparently, all the NSABP research defines a negative margin as not touching; they don't distinguish between "close" and "wide" in their data.  I thought this was kind of interesting:

 The relationship of the status of margins following LE of DCIS to IBTR, particularly the definition of what is free, continues to be controversial. NSABP pathologic practice regards the boundary of a tumor to be free if sections do not reveal its transection by ink. Estimates of being too close, at, or near are considered vague and conjectural.^{[4,5,7-10,17]} Indeed, the extent of a free margin that may be necessary to reduce IBTR following lumpectomy has not been inarguably demonstrated and, if excessive, may preclude satisfactory cosmesis, the fundamental purpose of that type of conservative surgical treatment. Involved margins in the B-17 trial represented an independent risk factor for IBTR at 5⁴ but not 8⁵ years of follow-up, a finding that coincides with those in this report after 10.5 years of observation. Our data reveal that the degree of freedom of margins was almost twice as frequently less than 1.0 mm than it was 1.0 mm or more, an observation that coincides with the senior author's impression in consultative practice. This may reflect an intraoperative difficulty in assessing the freedom of margins for very small, impalpable lesions that cannot be seen or felt despite the presence of a guide wire. It is noteworthy that the frequency of IBTR recorded in trial B-17 and in the trial B-24 placebo group does not exceed that noted in several reviews of retrospective studies.^[18,19] We maintain that margins should be free of disease, although when breast conservation is desired, as in trial B-24, margin status may not be necessary provided tamoxifen is administered as an adjuvant to XRT.

http://www.medscape.com/viewarticle/559971_4 

We had a really good meeting with the radiation oncologist today.  She started by telling us that she had already spoken to BS and oncologist.  She also told me she had brought my case to the Breast Cancer Center Conference at the university (like a tumor board--pathologists, oncologists, breast surgeons, etc.).  The consensus was that I did not need a re-exicision.  The reasoning is that they have confirmed (by specimen radiography) that all the calcifications were removed.  Also I have very favorable pathology (intermediate grade, no necrosis).  Also that the extra DCIS that showed up on the lumpectomy pathology was "away from the clusters of calcifications," and thus most likely not part of the "tumor."  She said that she was as confident as she could be that radiation plus a boost to the tumor area would sterilize or kill all the remaining cancer cells.  She said she will be doing the boost throughout the entire 5 weeks of therapy, not just at the end. She said that with radiation but without a boost my risk of recurrence would be 7% and with a boost would drop to 3%.  That was much lower than I had expected, and was a number I could accept.  She also said for followup, I would have yearly mammograms and MRIs, so that rotating on a six month schedule, so I would be closely watched.

I told her that my concerns had been that so much of the published material says that they want larger margins and I just needed an explanation I could understand why that didn't apply to my case.  She reiterated, what I already knew, that there is a lot of controversy about margin status, and it depends on whose data you are looking at.  (I kind of knew that from what I have read).  She said of course with would have been better if the surgeon had gotten 1 mm margins (one of the pathologists said if he had just cut a tiny bit further he would have), but they did not believe that a re-exicision would change the outcome.  (I think this has to do with the fact that they believve the residual DCIS is not a a part of the "tumor.")

Anyway, in the end, the fact that a tumor board had reviewed my case and that my recurrence risk is about 3% was enough.  I feel much (MUCH) less stressed and anxious.  I will have the simulation (to set up the radiation) tomorrow and will start the therapy itself in 2 weeks.  This means I should be done about May 21.  
 

Just wanted to add this all in case someone else with close margins starts to read and finds my post.  In the last couple of weeks, I have read A LOT about margin status, and I have come to realize that it is a very complicated and controversial subject.  Most of the research is retrospective.  What counts as a "close margin" is defined differently in different studies.  And there is no real consistency in how the pathology is handled.  I decided I could not make the decision myself about whether my margin was wide enough.  However, I could go with the consensus of specialists, including not only my 3 physicians but also a group of specialists who reviewed my case independently.  I just feel really lucky that in my case everyone seemed to agree.

This is mainly my coda to this thread (written again in case anyone who is concerned about margins finds this thread in the future).

 I saw my oncologist today and told him I was doing radiation without further excision.  I said that I had needed an explanation that made sense to me, and that the radiation oncologist had helped me understand why, even though NCCN guidelines say 1 mm is the minimum to be adequate, my .5 mm margins were okay.  I won't go through the explanation again (basically what I wrote above).  But in the course of our discussion, the oncologist said one more thing that really helped.  He said "DCIS is a process not a number." Somehow hearing it this way clicked for me. I get that obncologists understand the processes, and are guided by the totality of the evidence, rather than just going (blindly) by the numbers.

 I also told him I had listened to the NIH Consensus Conference on-line and that I understood from that (and from further reading) that the margin literature and recommendations are "controversial."  He said that is exactly the right word.  He also said that NCCN guidelines assume everyone is the same, and they're not.  I don't think he meant this as a criticism of NCCN, but just that it's in the nature of guidelines to be making general recommendations, not dealing with specific cases. 

Anyway, that is my last margin consult with a physician.  I am moving forward to radiation and not looking back.   As several people have said to me, there comes a time when you have to trust your doctors and not look back.  I am now anxious to get radiation started and finished.