[DanaH]

Can FISH be wrong?

by DanaH on Tue May 21, 2013 4:01 pm

Hi everyone, I hope someone can help me understand the results of FISH. Some history.

I had my 1st BMB in December, 2010, 8% PC, Cyclin D1positive, negative for CD56 and p53 negative (these are from the Core Biopsy results, not Flow Cytometry on Aspirate). FISH and chromosome Analysis Cyto came back normal, no abnormalities.

I had my 2nd BMB in January, 2012, CD138 immunostain, areas of 5%-10% and areas of 10%-15% PC, Cyclin D1 positive, w/ kappa LC predominance, Negative for CD56, CD117 and CD20. No FISH or Chrom Analysis were performed on this sample.

PCLI was 0% on the January 2012 BMB sample. (Over expression of Cyclin D1 confirmed, no Cyclin D2 or D3, indicative of slow proliferation.)

I was recently told that with Cyclin D1 over expression, in theory, my FISH should have been positive for t (11;14).

My quesiton: Could the cell population (500 nuclei) that were probed, not have tested positive for this translocation because they just did not capture or test a sampling of the cells that contain this abnormality?

Or is this a true representation since ALL of the clonal cells would have the abnormality (no matter where the sample was taken from) IF I have a single original clone that may or may not be proliferating.

Do I need another BMB to figure out if I have the t (11;14) translocation? So trying to get a better understanding of all of this. Thanks to anyone who will try to help me understand.
Thanks,
Dana

[Multibilly]

Re: Can FISH be wrong?

by Multibilly on Tue May 21, 2013 5:44 pm

So, it is my "understanding" (and I underscore that I am no expert here and you should verify all this with your doctor), that you can have different mutant cell lines with different mutations (deletions, gains, translocations), which in turn can all have different and non-uniform distributions in your bone marrow. So, you can in fact be subject to the luck of the draw on whether you would detect a given mutation in a FISH test, and even come up with different results depending on what part of the sample was probed.

Regarding Cyclin D overexpression being an indicator of (11;14) translocations, I think it is the other way around. That is, the presence of a t(11;14) translocation signals the likelihood of Cyclin D overexpression.

Again, double check all this with an expert.

[Dr. Jason Valent]

Re: Can FISH be wrong?

by Dr. Jason Valent on Wed May 22, 2013 3:24 pm

I suppose I should leave a disclaimer that I am not an expert on the perfomance of the FISH testing or cyclin D1 staining.

Translocation 11;14 results in up-regulation of cyclin D1. Cyclin D1 stain is an immunostain done on the biopsy (and is positive if found in excess in the nucleus of the plasma cell).

There are studies that have looked at your specific issue. If you look at large population of myeloma patients about 30% will have "positive" cyclin D1 immunostains and only about 20% will have FISH + 11;14. 5% will have 11;14 by conventional karyotype. Some of this may have to do with what is deemed "positive" or "normal" on analysis of the D1 immunostain.

It is possible that the sample obtained and sent for FISH was not adequate (a late "pull" in the aspirate) from the bone marrow aspirates.

All that said, I do not think that you need retesting for 11;14. It has been shown not to be an adverse prognostic finding.

[DanaH]

Re: Can FISH be wrong?

by DanaH on Wed May 22, 2013 3:44 pm

Dear Dr. Valent,

Your response was very very helpful. Your last sentence is what I needed to hear !

All of they very best to you !

Dana

[DanaH]

Re: Can FISH be wrong?

by DanaH on Wed May 22, 2013 3:46 pm

Hi Multibilly,

Thanks so much for your response.

All of the very best to you,

Dana

[Multibilly]

Re: Can FISH be wrong?

by Multibilly on Fri May 24, 2013 1:43 pm

Multibilly wrote:

So, it is my "understanding" (and I underscore that I am no expert here and you should verify all this with your doctor), that you can have different mutant cell lines with different mutations (deletions, gains, translocations), which in turn can all have different and non-uniform distributions in your bone marrow. So, you can in fact be subject to the luck of the draw on whether you would detect a given mutation in a FISH test, and even come up with different results depending on what part of the sample was probed.

BTW, I just met with my oncologist and verified that what I said above was accurate.

You can indeed have multiple clonal lines in different overall percentages and these can be distributed non-uniformly throughout your marrow. New mutations can also develop over time and co-exist with mutations that are already present.

[DanaH]

Re: Can FISH be wrong?

by DanaH on Fri May 24, 2013 2:38 pm

Hey Multibilly,

Thanks so much for your followup.

This is just a crazy disease. So with that said, any idea if one of those clonal lines could be expressing the proteins that create an "m-spike" yet another clonal line could be present in another section of your marrow and be non-secretory? And if this could happen, how on earth do you monitor your disease?

All of this really makes me nervous. I am smoldering, I do have a stable m-spike over the past 30 months, abnormal FLCr, IgG kappa, no BJ, osteopenia, no anemia, no hypercalciumia, or renal issues (although I have small amounts of albumin on 24 hour urine samples over the course of the past 24 months. MRI of spine clear and PET/CT w/ FDG, no avid FDG lesions.

Thanks if you can share any additional info.
Dana

[Multibilly]

Re: Can FISH be wrong?

by Multibilly on Fri May 24, 2013 3:32 pm

It is a crazy disease, as are most cancers.

Sorry to make you nervous. That absolutely wasn't my intention. I am smoldering as well and I just take comfort in understanding the details as best I can.

My suggestion is to not to get hung up on FISH and cytogenetics (which is also the advice of my oncologist). Your blood serum and urine tests (which include your Freelite tests), as well as your plasma cell count in your bone marrow from your BMB, are going to give you the big picture.

As far as your question on different clonal lines being secretory and non-secretory, I haven't a clue. But why are you going there since you've had a BMB? You have no CRAB and are smoldering and you very well may smolder the rest of your life, which I sincerely hope you do.

I just had a very uplifting meeting with my oncologist and I realized I was really getting down into the weeds on this disease. It's good to understand these things (at least for me), but it is not good to dwell on these things.

Off to a 3-day music festival to lose myself in sonic bliss with my wife.

[DanaH]

Re: Can FISH be wrong?

by DanaH on Fri May 24, 2013 7:43 pm

Hi Multibilly, thanks again for your reply. Your info didn't make me nervous, the prospect of progressing does, so no worries on that one being related to anything you provided. I do appreciate you sharing the info you have gained from your onc.

Have a great time at your festival!

Best,
Dana

[tpt]

Re: Can FISH be wrong?

by tpt on Sat Sep 07, 2013 8:37 pm

Hello,

Dad's 2nd biopsy just came out and I hope you can help me figure it out.

The TP53 was one of the five probes. In the conclusion, it was written that "this test is negative for multiple myeloma FISH panel. Kindly correlate FISH results with other clinical findings."

Neverthelesa, his 1st BMB, approx. 2 years ago, showed TP53 trait. BMB was performed on his illiac. Does this mean he is, by this BMB, normal-risk? Can FISH be wrong?

Second, how do you know how much plasma cells contained? Dad was tested poaitive for CD38 and CD138, at 12.0% and 12.4%, resoectively. But at the bottom of the report, it was written "remarks: CD38 + CD138 = 11.8%." Does this mean his PC is 11.8%?

Thanks.