Assay Results/Prognostic Significance

kencooperjr,  

Since I didn't have DCIS and haven't done directed research on it, I was hoping someone else would answer, but I'll try to help.  

I've never read that Ki-67 was taken into consideration for DCIS because chemo is not considered for treatment.  With IDC, Ki-67 is an indicater of how agressive the turmor is proliferating.  Generally chemo is more effective against cancer that has high proliferation.  Some docs consider Ki-67 as significant and others do not.  With ER+ IDC, it is one of the factors in your Oncotype DX score, so is taken into account there.  I think where it becomes significant is when a high Ki-67 % conflicts with a low Oncotype score, then causes the more obvious treatment path to become cloudy.

Because your wife has DCIS and will not be getting chemo, the Ki-67 shouldn't make any difference in treatment choices.  Only if the cancer has become invasive is there a consideration.  And thankfully for her, it is not invasive.  

kencooper - if your wife has pure DCIS then her stage would always be O.  I concur with doxie - Ki67 is immaterial in DCIS because it does not affect treatment decisions.  The only treatment beyond radiation, if necessary, is hormonal therapy which would be connected to the hormonal receptor information, not the Ki67.  It is also important to note that all areas of DCIS within the breast are not necessarily homogenous - you may have an area with a lower Ki and different percentage of receptors, and an area with higher numbers in a different location of the mass.  This is why the final pathology report is what treatment is based on, not usually the biopsy numbers - post-op pathology gives the full picture.  If your wife's diagnosis is pure DCIS, with no invasive component, why are you requesting a Mammaprint?  My understanding of eligibility for Mammaprint is that a stage I/II dx is necessary, so the cancer would need to be invasive.  You should also check with your insurance company regarding payment for Mammaprint.  It is very expensive test (approx. $5,000) and many insurance companies will not pay for it, mine included.  Since the information provided by Mammaprint would not likely change treatment your insurance company may be even more disinclined to fund the test. I am wondering what information it will provide for you going forward.  I believe that there is a newer Oncotype Dx for DCIS - here is a link to the info: 

http://www.oncotypedx.com/en-US/Breast/PatientsCaregiversDCIS/OncotypeDX/Overview