Curious...What was your FISH?

In 2002, I was diagnosed with a 2.4cm IDC, negative nodes, ER+, PR+ and IHC 3+. At that time, I did not qualify to enter the Herceptin clinical trials. When all the good news about Herceptin started to come out, I decided to start "late" Herceptin. I started Herceptin 2 years after my diagnosis.

After my first Herceptin treatment, I had many side effects. Being a Medical Technologist, I knew about the FISH test and asked to have it done just to double check I was actually Her2 positive. After weeks (and 2 more Herceptin infusions), my FISH test came back negative (1.5).

My original IHC test was done at a local hospital lab. (I switched to a large breast cancer center after diagnosis.) The pathologist at the local hospital admitted that in 2002, the IHC test was new for them and they didn't do many of them. They found out they were getting quite a few false negatives and false positives. In 2003 because of this lack of compliance, the lab changed the way they were doing the IHC test.

After getting many opinions, I was told that if you are really IHC 3+ and FISH negative, you can still benefit from Herceptin. The tests are measuring two different things. IHC tests for a protein on the outside of the cell. FISH measures the genetic material inside the cell. IHC can be done in most hospital labs but FISH, a more expensive test, needs to be done in a reference lab. IHC has more varibles for error and also is a more subjective test than FISH.

I stopped the Herceptin and asked to have the IHC repeated. After more weeks, I was told that the local hospital lab could not give me and "accurate" IHC result because the tissue sample was too old. I believe in my case the original IHC test was done incorrectly--I am not Her2 positive and never was. I'm very glad I did not go through a year of Herceptin for no reason.

I know I am a very rare case. It does seem scary to make such a large commitment of a year of treatment when there are still questions about the accuracy of Her2 testing.


So as Saleboat said, "it may make a lot of sense to have one's pathology done by a high-volume lab that has a lot of experience with these two tests."

[kristen]

My FISH was 7.6.

Does anyone know what the normal range of FISH is and what does it mean your FISH. Mine was 6.1, and I have no idea what it means.
Marcia

[Lolly]

Marcia, here's a link to the "Tests and Treatments" page from this site. You can click on the FISH link to read all about it. <3 Lolly

Tests and Treatments
http://her2support.org/a/newher2_004.htm

[jener8er]

Hi everyone, I still don't know why my FISH test was SO high - it seems at least double to everyone elses here. Does anyone here know if this means anything? I haven't seen anyone else with anything over 8, yet mine was 15.2? Could mine be wrong? Why is it more than double any other result that you all have? Does anyone know if this means I'm better off being on Herceptin, or am I just buying time for something that is unstopable? Please help me not to panic....

[karenann]

My FISH was 6.3.

Karen

Jener8er, don't panic!
The report on my FISH analysis states, "...Because signal counting is performed by the Metasystems instrument, the mean number of signals refers to signals per "computer tile" rather than tumor cell. The number of cells per tile varies as a function of tumor cell density and cell size."
My report shows the Mean Number of signals of Her-2/neu in my sample to be 19.4 signals. But the lab that performed the FISH on my sample looks at the HER2 factor in two ways; the above mentioned number of signals per computer tile, and also by looking at the number of signals on chromosome 17. The lab then reports the FISH positivity as a ratio of HER-2/neu signals to CEP-17 signals, and in my case it was then 4.26.

So I think the question for you is, did the lab that performed the FISH on your sample use only one point of reference and report your FISH as the Mean Number of signals, which could give you an seemingly high degree of FISH positivity, when in reality it would simply be showing the number of signals on the tile which according to the explanation above can be variable depending on how many cells are on that particular tile. If you can't decipher this from the report, see if the phone number of the lab is noted on the report, they often are, and give them a call asking for an explanation. I've found labs to be very helpful that way, but they may ask you to sign a release of information form first. If they're out of your area, they can fax the form to you and you can fax it back, to speed things up.

Good luck, and again, don't panic...

<3 Lolly

Jener8er, don't panic!
The report on my FISH analysis states, "...Because signal counting is performed by the Metasystems instrument, the mean number of signals refers to signals per "computer tile" rather than tumor cell. The number of cells per tile varies as a function of tumor cell density and cell size."
My report shows the Mean Number of signals of Her-2/neu in my sample to be 19.4 signals. But the lab that performed the FISH on my sample looks at the HER2 factor in two ways; the above mentioned number of signals per computer tile, and also by looking at the number of signals on chromosome 17. The lab then reports the FISH positivity as a ratio of HER-2/neu signals to CEP-17 signals, and in my case it was then 4.26.

So I think the question for you is, did the lab that performed the FISH on your sample use only one point of reference and report your FISH as the Mean Number of signals, which could give you an seemingly high degree of FISH positivity, when in reality it would simply be showing the number of signals on the tile which according to the explanation above can be variable depending on how many cells are on that particular tile. If you can't decipher this from the report, see if the phone number of the lab is noted on the report, they often are, and give them a call asking for an explanation. I've found labs to be very helpful that way, but they may ask you to sign a release of information form first. If they're out of your area, they can fax the form to you and you can fax it back, to speed things up.

Good luck, and again, don't panic...

<3 Lolly