Assay Results/Prognostic Significance

kencooperjr

A few days ago the following was posted (to the incorrect forum - DCIS)

My wife has quite recently been diagnosed with breast cancer (DCIS) with an overall grade of 1. After surgery the pathology report indicated the tumor size as 8mmx7mmx6mm. Five sentinal lymph nodes were examined and all five were without tumor cells.

The following data were defined at the initial biopsy: ER: 100%, HR: 100%, Her2/neu: 1.2, Ki-67: 8%

The after surgery pathology report is:                      ER: 96%,   HR: 100%, Her2/neu: 0.8, Ki-67: 42%

The numbers are close except for the Ki-67 wherein the after surgery is about five times the initial biopsy value. Is this difference normal or not? What would be the significance of this value (42%) in terms of treatment as we go forward?

A breast surgeon said "...totally ignore the ki its a prognostic number, we don't use it to make any decisions, except make my blood pressure go up when it is high (greater that 75 %).  It doesn't impact on any treatment recommendations, doesn't factor into any treatment guidelines....". I have found in my researching of the topic that many doctors (oncologists/surgeons) don't even ask for the Ki-67 test and when it is available there still seems to be an issue as to treatment options. Have had other people suggest (based on empirical evidence) that a high Ki-67 index may even be due to the healing process from the biopsy and NOT and cancer! We have elected to have a MammaPrint test which seems to be pretty definitive. Another comment I found was that if the Ki-67 index was so high (42%) then why is this tumor a Stage 1 as opposed to a stage 2.

I have received several comments regarding this topic. I have also spend a fair amount of time researching the  topic using the web. Based on my searches and comments from doctors I am really wondering if the Ki-67 is really useful for making treatment decisions!

Any comments as regards the Ki-67 index would be appreciated.

Thanks - Ken Cooper

doxie

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.  

dltnhm

Ken,



Although there was DCIS present, I also had IDC.



I do want to address something you wrote. Early on you write that your wife's grade is a 1. But later you ask why it is staged as a 1 not a 2.



If your wife's tumor is pure DCIS then her cancer is neither a stage 1 or a stage 2. Your questions and concerns about the Ki-67 point to the grade.



It is easy to get grade and stage mixed up in these early days. Keep that in mind as you seek more information.

SpecialK

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