Ki-67 discrepancy?

kencooperjr

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? Why would the after surgery value be so much larger?



Thanks for any comments/help with this question/issue.



Ken Cooper

Annette47

Hopefully someone more knowledgeable will come along to answer your question, but my understanding is that the significance of Ki-67 is not really known for "pure" DCIS (in invasive cancer, higher numbers can indicate a more aggressive tumor, but not it does not necessarily work the same way for DCIS).

Many docs (mine included) don't even run the test for DCIS samples, so assuming that your wife does have DCIS without any invasive component, I doubt it would have any impact on her treatment plan.

As for why the numbers would be different, not all tumors are completely homogenous, so depending on where in the tumor you sample you might get different results.   

MarieKelly

I used to be around here a lot but only rarely the last few years -today being one of those rare days.  I can't recall specifics and unfortunately I long ago deleted all by bookmarks on breast cancer, but I recall info I had saved and probably posted here somewhere long ago that relates to this issue.  Since Ki-67 is a marker for rapidly dividing cells, with low being slower and higher being more rapidly dividing, I recall something about the possibility of falsely high positive results for Ki-67 if a sample of tissue is stained for Ki-67 in which that tissue is in the process of healing...such as recently underwent a biopsy. Staining positive for Ki-67 is not something specific to cancer cells because it's simply identifying cells that are undergoing a process of prolieration (division) which of course, would be something you'd expect cancerous tissue to be doing but ALSO what you would expect any tissue undergoing the process of healing to be doing. A biopsy traumatizes tissue and that tissue then goes through a healing process with an increase in the amount of cells dividing...so KI-67 increased. That's all I can remember off hand, Have to go off for the day but will try to find this info for you later today or tomorrow. Can't promise I'll find it again, but will try. 

Just a quick other note. A Ki-67 that high doesn't normally occur with a grade 1 cancer.  Just not jiving at all - somethings not right and it definately needs further assessment by another pathologist. 

MarieKelly

http://www.cap.org/apps/cap.portal?_nfpb=true&cntvwrPtlt_actionOverride=%2Fportlets%2FcontentViewer%2Fshow&_windowLabel=cntvwrPtlt&cntvwrPtlt%7BactionForm.contentReference%7D=cap_today%2Fcover_stories%2F0307brcancer.html&_state=maximized&_pageLabel=cntvwr

"...However, detailed analysis of the two discrepant tumors showed something more intriguing. A key factor in both tissue blocks was a cavity from the patient’s previous needle core biopsy. "So the block contained tumor, but also adjacent to the tumor itself we could see the needle track with inflammatory tissue including macrophages ” Dr. Bloom says. “In the biopsy track there was granulation tissue proliferating like crazy.  So lots of cells were expressing KI67, but they were not tumor cells." Dr. Bloom also notes that a minor component in the recurrence score is CD68 expression, a macrophage marker. “We saw numerous CD68-positive macrophages in the tumor block,” he says, “but no tumor cells expressing CD68.” Taken together, he believes these findings can explain the discrepancies between the recurrence score and IHC results. Both patients with discrepant results elected to receive chemotherapy, he told CAP TODAY, “even though without this test they would have received only hormonal therapy. There is no doubt in my mind that both of these patients were significantly overtreated.”...

kencooperjr

It turns out I have made a very serious error in posting to this forum (DCIS). My wifes Histological type is a IDC with DCIS present. I have found out that this is mormal - the Histological type being IDC and some DCIS present.

However I do feel the last two posts do shed light on my original question.

Thanking you for your followup!

Ken