"Less than 1mm" is not a clear margin, right?

I can tell you that my final path from my mast showed multifocal areas of less than 1mm margins on the chest wall side and 1mm margin on the anterior side.   I now have to do rads.  so sorry.

I had one margin that was .5 mm and I was sure I was going to have to have a re-excision.  But every one of my doctors (surgeon, oncologist, radiation oncologist) was ADAMANT (not wishy-washy at all) and said I didn't need one.  My case was then presented to the tumor board and they agreed no re-excision needed.  It has something to do with which margin and how the pathology was handled and whether your DCIS is extensive or multifocal, etc.  I never really understood the intricacies of how  the pathology was interpreted.  But I think the major question they ask is whether what is left is residual DCIS that can be handled by radiation or is part of the tumor that must be re-excised. 

  In trying to come to terms with this, I read a lot about margins and decided in the end that I could not understand the details of how the margin was assessed.  I am now just about to finish 5 weeks of radiation with concurrent boost.  My recurrence risk is supposed to be 3%.  I do not know if your case is similar to mine, but just to say I did jump to a conclusion that wasn't warranted about having to do more surgery. 

I have had a mast and less than 1mm margins, and two sets of surgeons and oncologists and radiologists have insisted that I don't need rads--that it's a clear margin.

I had one margin at 1.2. I don't think it's cut and dry . . . 1.2 = clear or not clear. A lot more info was used before the tumour board decided I needed a mastectomy. Since my cancer was multi focal, multi quadrant, Grade 3, necrosis and ER/PR negative, no one felt confident that there wasn't more cancer in my breast. It was a combination of all of it that caused the Board to recommend a mastectomy.  I believe their recommendation would have been different had my DCIS not been as aggressive.

What is considered to be an "acceptable" margin will be different for those who have lumpectomies vs. those who have mastectomies.  In many of the posts above, it's not clear if someone had a lumpectomy or a mastectomy, and that's a big factor.

With a mastectomy, there are only tiny scrappings of breast tissue left so there are a lot fewer places where cancer cells can hide.  For this reason, usually 1mm and certainly 2mm is considered to be an acceptable margin (assuming that it's DCIS that is near the margin).  At the time I was diagnosed, with 1mm margins (or greater), radiation wasn't considered for those who had mastectomies for DCIS.  These days, based on more recent studies, sometimes radiation will be suggested for those who have 1mm margins after a mastectomy.  And if the margin is smaller than 1mm, most often radiation will be recommended. 

It's different for those who have lumpectomies.  After a lumpectomy, there's still lots of breast tissue, and one of the problems with DCIS is that it sometimes "skips" in the duct.  In other words, there might an area of DCIS, then a small space (1mm or even more) and then the DCIS continues.  For this reason, most docs feel that the minimum acceptable margin for those who have a lumpectomy is at least 2mm and often 3mm.  And radiation is sure to be recommended for anyone whose margins are less than "ideal" - and ideal is usually considered to be 10mm.  Of course there are exceptions, based on the pathology of the DCIS.  If you have DCIS that is multifocal and/or if it has a pattern of "skipping", then even wider margins may be required.  If you have a tight single focus of DCIS, then perhaps smaller margins might be acceptable or it might be possible to forgo radiation with margins that are not quite 10mm.  The size of the area of DCIS and the grade also come into play.

So there is no simple answer - it depends on whether you had a lumpectomy or mastectomy, it depends on your pathology, and frankly, it depends on the preference of your surgeon.  Some surgeons are more conservative and insist on wider margins; other surgeons are less conservative and are willing to accept smaller margins.

crunchypoodle- I know a mast is a very scary thing to think about.  Believe me, I struggled with it and still do.  I was pretty shocked when after I was told I still needed rads.  I have also read some threads about recurrence after BMX and it scares me.  For me, I 100% trust my surgeon and dong the rads makes me feel as though i am doing all I can to get rid of this for good.  Hope you are able to make some kind of peace with whatever you decide to do.

We are in the same city....if you ever want to talk via phone or even meet up for coffee I am available.  Sorry you are going through this and it does truly suck.  I always feel like "the good cancer, huh?"  Doens't feel so 'good'.

He's not suggesting rads for you?  I'm glad you got the news you wanted and wishing you nothing but happy baby thoughts!

That I understand and will be thinking happy baby thoughts for you.  (and No cancer!).  My rad onc told me my risk of recurrence without rads was at least 35% and with rads we could bring it down to 4%.  Frankly, I thought my numbers would be much lower than that.  Hope to hear you are pregnant soon!

Hi Crunchy...........

I had a lumpectomy and a re-excision 2 years ago.  My "deep" margin near the chest wall had less than 1mm of a margin.  The surgeon told me that that she went down to the muscle fascia and that there was no more to cut out. She said radiation was recommended.

I hope this helps..

hugs..Kosh

I'm struggling with the <1mm margin debate right now myself.  Had bilat mast and at first no one suggested rads.  Now getting a "lean towards" but that it depends on my risk tolerance.  Most rad oncos have said no.  My Mayo onco was on the fence and asked 4 colleagues:  2 yeses and 2 nos.  It is split out there.  I'm grade 2 and 39 years old.  Trying to make the decision now.  Thanks for all the posts to contribute towards my knowledge base!

crunchypoodle: Sorry to hear they found more.  You'll ask about the fascia (I think we are in two different threads together)??  Have you decided about reconstruction?  I'm regretting my decision to do immediate since rads are on the table.  Wished I'd seen the mastecomty does not equal no rads posting before surgery.  But back then I think I was focused on the bilateral vs. unilateral decision.  It is a journey and we can only absorb so much at any one point. 

Best wishes to you in your surgery!!!  

My BS was totally against me having radiation. Said it wasn't necessary - even with my positive margins because she removed the fascia and she doesn't believe it will spread. I kind of wish that I would have gotten another opinion before having radiation, but with 4 specialists recommending it and several others in the same situation as me having it, I decided to go ahead with it. (I am grade 2 also, with no node involvement.)