Confused about significance of Ki-67

Brightness456

To add to my confusion, after my latest consult (with a team of doctors including an MO, RO and BS) two doctors said they weren't convinced I would even need chemo after my lumpectomy, perhaps just radiation. Apparently I'm a unique case...

S12Clear

QuinnCat, they do include it but my MO said that they have not perfected the method of evaluating the cells they are analyzing; a human evaluates/counts them. That is why he relies on the other results of the Genomics test. Now I am wondering, does a human determine that score also, or is it done by computer? Hmmmmm.

QuinnCat

S12 - I'm curious....what "other results," other than the reports on hormones? When I had the test there was very little reporting of the inner workings of their propriety test....ie, those 20 odd factors. The actually didn't even report Ki67 when I had the test 2/2012. Has that changed?

S12Clear

Brightness456, it will all hinge on the pathology results after surgery. I was freaked out by my biopsy pathology report and follow-up MRI scan and had decided to have a BMX - and then my very smart, very cut-to-the core CNP laid it out: "your biopsy showed us a lot, and we are running with it because you stand a chance of an almost 100% survival rate with a lumpectomy and radiation and ARI." So I decided to calm down and follow her direction and conviction. Best thing I've done; thank God I didn't insist on BMX!

S12Clear

QuinnCat, if you go to http://www.oncotypeiq.com, you can read all about how the test works and what it will provide to you and your MO. I'm not sure yet of all the inner workings of the test, but understood from my MO that he trusts as a tool in deciding whether or not to have chemo.

Good luck!

BarredOwl

DNA =======> mRNA ======> Protein

DNA is "transcribed" to produce messenger RNA ("mRNA").

mRNA is "translated" to synthesize the protein encoded by the DNA.

Ki-67 determinations by the pathologist and the Oncotype test use distinct methodologies (IHC vs qRT-PCR) to detect different biomolecules (protein vs mRNA).

Ki-67 measurement by the pathologist detects Ki-67 PROTEIN. Antibodies are used to stain tumor cells ("immunohistochemistry"), and it is reported as percentage of cells with positive staining for Ki-67 protein.

The OncotypeDX test for invasive disease assesses gene expression from 21 genes (16 cancer-related genes and 5 control genes). It uses quantitative methods of determining mRNA levels (using quantiative Reverse Transcription/Polymerase Chain Reaction). The level of Ki-67 mRNA expression is not reported separately.

BarredOwl

BarredOwl

General Information - Ki-67:

Ki-67 is a protein that is a marker of cell proliferation or cell growth (a higher percentage suggests more dividing tumor cells).

In general, rapidly dividing cells may be more responsive to chemotherapy. The 2015 St. Gallen panel commented:

>> "There can be little doubt that Ki-67 scores carry robust prognostic information [24], and that high values predict the benefit of addition of cytotoxic chemotherapy [25], but definition of a single useful cut point has proved elusive both because Ki-67 displays a continuous distribution [26], and as a result of analytic and preanalytic barriers to standardized assessment [27]."

In other words, despite the results of studies which report some prognostic and predictive value, there are technical issues with determination of Ki-67 percentages by standard IHC methods, including interobserver variability (different results when different people perform the test on the same sample) and lack of reproducibility across laboratories, as explained in detail here:

>> Polley (2013): "An International Ki67 Reproducibility Study"

>> http://jnci.oxfordjournals.org/content/105/24/1897.full

>> (Free PDF available via link)

Also, different studies use different values as cut points or cut-offs between what is considered "low" or "high" Ki-67.

This can make it difficult to rely on the results of clinical studies in which Ki-67 was determined in other labs and to interpret the clinical significance of a Ki-67 test result based on such studies. Accordingly, some institutions no longer perform Ki-67 testing (at this time), and clinical consensus guidelines (e.g., from ASCO) do not generally support the broad use of Ki-67 protein (determined by standard IHC) to guide adjuvant chemotherapy decisions.

Patients should not hesitate to ask their medical oncologist for his views on the significance of their Ki-67 result and how it should be weighed in connection with your treatment decisions.

BarredOwl

BarredOwl

The OncotypeDX test for invasive disease ("21-gene" test) is a "gene expression profiling" ("GEP") test. Molecular biology techniques (quantitative "RT-PCR") are used to determine the mRNA levels of 16 cancer-related genes and 5 reference or control genes from a sample of the tumor.

DNA ==> mRNA ==> Protein

If you recall from biology class, genes are made from DNA. In the nucleus of the cell, mRNA "copies" of actively expressed genes are made by the process of transcription. The mRNA is then exported from the nucleus into the cytoplasm, where it is used by the translational machinery of the cell to direct the synthesis of the encoded protein.

The level of a particular mRNA reflects in part the production of that mRNA by transcription, and is thus a reflection of the level of gene expression, which may be high or low. A test that evaluates the gene expression from multiple genes is a "gene expression profiling" test.

The levels of the mRNAs are used to calculate a Recurrence Score, using a mathematical algorithm that accords various weights to the different test genes. Regarding how the test works, here is a peer-reviewed publication from the scientific medical literature with some background:

Sparano and Paik (2008): "Development of the 21-Gene Assay and Its Application in Clinical Practice and Clinical Trials"

http://ascopubs.org/doi/pdf/10.1200/JCO.2007.15.1068

Figure 1 shows the test genes (blue boxes) and control or "Reference" genes (gray box), plus some information about the weight accorded to different genes tested and the Standard Risk categories:

As explained in the accompanying text, in general, "[h]igher expression levels of "favorable" genes (estrogen receptor [ER] group, GSTM1, BAG1) results in a lower RS (because of a negative coefficient in the RS algorithm), whereas higher expression of "unfavorable" genes (proliferation group, human epidermal growth factor [HER]-2 group, invasion group, and CD68) contribute to a higher RS (because of a positive coefficient in the RS algorithm)."

It is important to keep in mind that immunohistochemistry (IHC) methods used by pathologists for ER, PR, HER2, and KI67 testing detect protein not mRNA, while Oncotype entails a quantitative determination of mRNA levels.

BarredOwl

S12Clear

Wowzer, BarredOwl! That is perfect! I didn't know that the Ki-67 measured protein; and obviously didn't know how the OncotypeDX test worked. Thank you so much.

QuinnCat

Thanks Barred Owl, but on my question, do they now provide individual reporting on these 20 odd factors? In 2012 they did not, so was wondering how S12's MO could parse out other factors from Ki67

BarredOwl

Hi S12Clear:

I should add that the above explains how the "Recurrence Score" is determined in the test for invasive disease. The "prognostic" information provided about risk comes from various clinical validation trials that examined the correlation between Recurrence Score and certain types of recurrence risk(s) in groups of patients assigned to receive: (a) Tamoxifen alone; or (b) Chemotherapy plus Tamoxifen. The risk information is based on actual outcomes observed in groups patients and is statistical in nature.

BarredOwl

BarredOwl

Hi QuinnCat:

For the OncotypeDX test for invasive disease, to my knowledge (based on current sample reports found here), the Ki-67 mRNA level is not reported separately. It is one of 16 cancer-related mRNAs used to calculate the multi-gene Recurrence Score. The Recurrence Score and related prognostic information about risk are the main outputs of the test.

The reports include Quantitative Single Gene Reports for three mRNAs: ER mRNA, PR mRNA, and HER2 mRNA levels. These are provided in "units" and reflect mRNA levels, so they cannot be directly compared with the results of IHC protein determinations, but are usually generally consistent with IHC. The single gene reports are not as well-validated as the multi-gene Recurrence Score. IHC determinations for ER protein, PR protein and HER2 protein are generally considered to be more sensitive and reliable for treatment decisions.

We discussed your single gene report results a while ago: https://community.breastcancer.org/forum/108/topics/845324?page=4#post_4749499

BarredOwl

georgia67

I too am confused about this and don't know what to think about the answers I have received.  My score was 75%.  I was diagnosed February of this year and started chemo right away.  My oncologist and surgeon said not to worry about that score it just shows how well the tumor responds to chemo.  I still know what I have read is not good and this has influenced my choice of surgery.  I just finished my 4 rounds of AC and 12 rounds of Taxol.  I think I had every side affect listed and thought for a time my heart was damaged.  So far it looks ok.  Mine was 2.5 cm on left side.  Nottingham grade 2 with features of invasive ductal carcinoma BUT: some finding where unusual  that some infiltrating malignant cells present reminiscent of pleomorphic adenoma so the diagnosis of pleomorphic lobular carcinoma was considered.  E Cadherin stain is strongly positive, estrogen 30% and progesterone 5%, Her-e IHC negative.  I had a cyst removed from the same breast when I was 19 (67 now) and have had pain and nipple discharge off and on over the years.  The tumor now is on the bottom side of the breast and cyst was on top.  All of this kept bothering me so everyone of my doctors were pushing for lumpectomy because the tumor reacted so well to treatment ( does not show up on ultra sound now) but I can't trust the numbers or the feeling that this will bite me again so I have chosen a double mastectomy Sept. 1.  

QuinnCat

barredOwl- i have literally lost my shortterm memory being on hormone blockers--seriously. I even responded to you in that other thread. It has become debilitating. I will re-review later unless I forget I have a class to go to within the hour

Emily2008

QuinnCat, my recurrence was resting comfortably on my TRAM in my breast. It had likely grown from a small amount of breast tissue that was attached to the underside of the skin, but it grew downwards.

So it wasn't *in* the skin, nor was it *on* the chest wall. My MO said it was sort of in between the two.

BRCA makes life exciting, that's for sure.

QuinnCat

Emily - 8 years later? That's unnerving. For some reason, in my family, the women who survive breast cancer, all of us in our 50's except one, go on to have bladder and kidney cancer, though one aunt had two primaries like you (only a lumpectomy the first time). She was the only relative to get her first breast cancer much later than her 50's...at 79, then at age 84, then kidney at 85.

Emily2008

Quinn, yup, 8 years later. Age 35 at first diagnosis, and 44 at the second. It was like a ferocious punch in the gut because by that time I had stopped thinking and worrying about cancer. I distinctly remember saying at one point that I had closed the book on that chapter of my life. I suppose there was a sequel that was in the works and I had no idea about it.

Those bladder and kidney cancers in your family are primaries, not breast cancer mets? I don't think those cancers are in the BRCA family. I've always read and been told breast, ovarian, prostate, melanoma, pancreatic.

BucsGirl

BarredOwl - Thank you for posting all that wonderful information about the 2 tests. I was very concerned initially when reading this thread. My final pathology report has my  Ki67 at 99% (IHC). My ER was at 90% and PR at 50% with a HER2 score of 3+. My MO considered all of this when preparing my treatment plan. He mentioned the Ki67 index as being the highest, and mentioned some of the data you posted earlier. He also said that my cancer cells were dividing rapidly. I had forgotten all of that information until now. They give you so much information in the beginning. It's very overwhelming.

Anyway, I feel a little better now. I totally understand why they wanted to do the surgery sooner rather than later (before chemo). My initial report of the specimen taken for the stereotactic core biopsy had the same exact results. None of the percentages changed. I'm assuming that the final pathology report (post surgery) used the same methodology as the biopsy. Is that correct? Perhaps that's something I should ask my MO.

The following methodology was shown on my biopsy report:

Methodology:

All assays were performed on paraffin-embedded tissue fixed in formalin.

ER: The ER slides were incubated with the SP1 monoclonal anti-ER antibody from Ventana Medical Systems
Internal controls present and ER positive (as expected)/

PR: The PR slides were incubated with the 1E2 monoclonal anti-PR antibody from Ventana Medical Systems Internal controls present and PR positive (as expected)/

HER2: The HER2 slides were stained with the anti-HER2 (4B5) antibody from Ventana per the Pathway Kit instructions.

Percentage of cells with uniform intense complete membrane staining: 100%

Cold ischemia and fixation times meet the requirements specified in the latest version of the ASCO/CAP guidelines? Yes

H-Score: The H-score (Histologic score) is a method of assessing the extent of nuclear immunoreactivity, applicable to steroid receptors. The score is obtained by the formula: 3 x percentage of strongly staining nuclei + 2 x percentage of moderately staining nuclei + percentage of weakly staining nuclei, giving a range of 0 to 300.

****

Anyway, thank you for always bringing us the facts. I know it's super helpful to me (and I'm sure many others). I'm always comforted when reading things from medical journals and reports.

Thanks again!

BarredOwl

Hi TampaBayBucsGirl:

Re your question: "I'm assuming that the final pathology report (post surgery) used the same methodology as the biopsy. Is that correct? Perhaps that's something I should ask my MO."

It seems likely that the ER and PR testing methods were the same if done locally (by the pathologist at your facility), but it is best to check the actual surgical pathology report for methods and actual results. Regarding HER2 testing, there are alternative methods, such as IHC, FISH, and other ISH-based methods, so it is theoretically possible that a different method was used if further HER2 testing was performed on surgical samples. So please ask your MO and request a complete copy of your surgical pathology report (including any supplements or addenda) for your review and records.

With a HER2-positive tumor, a higher Ki-67 percentage by IHC is not surprising. However, (regardless of Ki-67), with no evidence of lymph node involvement and presumably estimated Clinical Stage IA (T1, N0, M0) disease, a surgery-first treatment plan is common. Under NCCN guidelines, neoadjuvant systemic therapy is typically considered with larger tumors (e.g., Clinical Stage IIA (T2, N0, M0); Clinical Stage IIB (T2, N1, M0; T3, N0, M0) and Clinical Stage lllA (T3, N1, M0)), although there may be appropriate exceptions.

By the way, with HER2-positive, node-negative (N0) IDC that was "T1" in size, and treated with a paclitaxel plus trastuzumab (Herceptin) regimen, you may be interested in the results from the APT Trial (ClinicalTrials.gov number, NCT005424510):

>>Tolaney (2015), "Adjuvant Paclitaxel and Trastuzumab for Node-Negative, HER2-Positive Breast Cancer"

>>Main Page: http://www.nejm.org/doi/full/10.1056/NEJMoa1406281#t=articleDiscussion

>>PDF version: http://www.nejm.org/doi/pdf/10.1056/NEJMoa1406281

In the above 2015 publication, "The median follow-up time was 4.0 years. . . "

Just recently, seven-year follow-up data was recently released at ASCO 2017:

>>Tolaney (ASCO 2017), Abstract No. 511, "Seven-year (yr) follow-up of adjuvant paclitaxel (T) and trastuzumab (H) (APT trial) for node-negative, HER2-positive breast cancer (BC)"

>>http://abstracts.asco.org/199/AbstView_199_191222.html

This abstract reports after "a median follow-up of 6.5 yrs . . ."

(Note: Results from meeting abstracts may be preliminary in nature. Those with pending treatment decisions should be certain to discuss any outside information with their medical oncologist to ensure accurate understanding and applicability to their particular situation.)

Best,

BarredOwl

_______________________

https://cancerstaging.org/references-tools/quickreferences/Documents/BreastMedium.pdf

"T1" = Tumor ≤ 20 mm in greatest dimension, and includes any of the following:

T1mi = Tumor ≤ 1 mm in greatest dimension

T1a = Tumor > 1 mm but ≤ 5 mm in greatest dimension

T1b = Tumor > 5 mm but ≤ 10 mm in greatest dimension

T1c = Tumor > 10 mm but ≤ 20 mm in greatest dimension

BucsGirl

Thanks BarredOwl! Yes, I'll definitely ask my MO regarding the full report. I'm only seeing the biopsy, pre-op, and post-op reports that were scanned into my online health records. The latter report didn't have any mention of their testing methodology.

Also, I'm happy to see the 7 year statistics. My MO gave me a graph chart from that study (the most recent one). I hadn't been able to find the actual report anywhere until now (thanks to you). He was very happy with the news, and he wanted to share with it me. Yes, it's very interesting! I'm hoping that I fall into that 98% group when all is done.

I also forgot to mention that I'd be in a worse situation today had they not discovered a spot on the mammogram. They couldn't find my tumor in the ultrasound. The radiologist at MacDill AFB referred me for a biopsy because he didn't like the way it looked on the mammogram. I'm thankful every day that it was discovered early enough. I'll never complain about military healthcare ever again.

QuinnCat

Emily - as far as I know, the kidney and bladder were primaries for my two aunts. For one Aunt, the bladder cancer showed up 20 plus years after her breast cancer, though I don't actually know for sure. I know that Aunt, the one with the 20 year plus gap, was not properly dx'd with her initial breast cancer. It was in the early days of mammograms and her first doctor told her to "watch it." They moved and a new doctor took it more seriously. I know the tumor was big by the time she had surgery, but she only had a mastectomy and no chemo. Not sure about hormone blockers. Could have been a very indolent tumor that resurfaced decades later in her bladder. Her daughter and I talk often, so I might ask, though she sometimes does not like to talk about such stuff. Ironically, she had BC too, in her 50's (she is 9 years out), but her brca test was negative. Her brother was positive.

As far as "brca" cancers. Every once and awhile I see new cancers that are theorized to be brca related in one more scientific FB group I belong to (Fun - hey). It could also be related to one's specific variant. Our family's variant is in the 8000 range and that is more associated with breast, rather than ovarian. Except for my grandmother, who would be the carrier, and it is confusing whether she had colon or ovarian cancer (but lived a very long life, age 89 and at least 10 years after this abdominal cancer), we are all breast cancer. I have never seen discussions of kidney, ureter, and bladder, other than my own family.

I guess I might be on more alert when my MO does a breast exam (of basically skin and implants). I'd like to think that 2% chance of a new primary, after mastectomies, is really 2% or ZERO!