DCIS and what's next

[srwest]

I was just diagnosed with DCIS this week. It was originally thought to be a papilloma. My tumor was 1.6cm  with 1mm margins.  In keeping with what appears to be the standard treatment, I am scheduled for additional surgery this Friday to remove some adjacent tissue to the duct and then on to a course of radiation.  My doctor said this was bad news and good news.  The bad, of course, was that it was cancer; the good was that it was in the duct.  My question is: I don't  understand why the additional surgery is necessary if the good news was that the cancer was entirely within the duct with a margin (though small).  Are they looking for additional cancer of another type while they're there or is it still possible for some cells to be outside the duct even with a margin? I'm also curious to know if I had a papilloma that became cancerous, or was it cancer all along?  I'm starting to realize how little I know about my situation and am trying to remedy that.  Everything I've been able to find this week on DCIS has explined what it is, but not why this apparently accepted manner of treatment is necessary.

[Dronne]

How wide a margin is considered to be truly "clear?"

[CCF-RN,MSN-rf]

Dear srwest:  Although a 1mm margin can be considered a minimum for safe margin, it is very small and most would prefer a wider margin, thus the reoperation.  DCIS means that the cells are within the duct and technically do not have the ability to spread - so it isn't really cancer - although the treatment is almost as aggressive as if it were cancer.  In the past radiation was given to higher grades of DCIS and some other types were excluded.  Recent studies show that all women with DCIS may benefit from radiation therapy.  It is impossible to say whether the papilloma had anything to do with the development of cancer.  A single papilloma is not usually a risk.

[surgeon]

How we treat various cancers comes from studying various options tried in thousands of cases, and comparing outcomes. DCIS is a challenge because it's so favorable: the question is how much treatment is enough; when is it too much? We know that in studies of thousands of people, the cure rate is higher if the margin around it is bigger than 1 mm. Likewise, recurrance in the breast is lowered by radiation. The problem is that with our current methods, we have no way of knowing for a single individual whether a given treatment is enough or too much. So we go by results from large numbers. With DCIS, there's some chance that, since it's in the ducts, it could have moved elsewhere within the ducts, or be elsewhere. So we lean toward widely treating the area with re-excision, and treating the whole breast with radiation. There are some studies to try to determine whether women with certain sub-types of DCIS can get along with less treatment. You may have heard the media reports in the last couple of days of one study that concluded that radiation shouldn't be omitted at all, which it has been in some situations. As to the papilloma: it's not really possible to say whether there's more than one thing going on. Women who have extensive papillomatosis (papillomas all over the place) probably have increased risk of developing DCIS -- having one here or there hasn't really been shown to be a significant risk factor. Whether you had a papilloma or not is something your doctors, who know the details, could answer better.