[Jean]

Hi AA, and thank you, I misunderstood the question.

Well, Since DCIS must be removed with clean margins and most dr.
recommend additional treatment such as radiation I would say yes,
that the odds of developing an invasive is there. The surgery itself
should not/or/ would not be the culprit, rather the doctor not achieving clean margins. (leaving behind trace amount) Treating DCIS is to reduce the risk of an invasive cancer.
If the DCIS is not invasive at the time of surgery - that does not
mean it cannot return as an invasive cancer later on. So the best answer to the question is if the DCIS is not invasive it is not considered cancer, but a pre-cancer. All DCIS can and is capable of evoling into breast
cancer. Dr. still do not understand the sub types of DCIS...what
is so concerning to me is that most if not all dr. treat DCIS with HER2
just like DCIS without HER2...and as Becky pointed out it is not so
easy via pathology to define the invasive portion and anything left
behind will have the strong chance of changing to IDC. So the answer is yes.

Jean