FISH Results-High Level Amplication

[lynne.risdon]

My HER2 ratio is 9.30 (High Level Amplication per the Pathology report.)
(The actual ratio is 139.32 divided by 14.98 CEP 17 chromosomes.) The FDA kit used was Pathvysion. I have been watching ratios disclosed in members e-mails and it appears that mine is on the high end. Oncologists tell me that the HER2 actual ratio's only significance is to determine HER2 status and that a higher ratio does not indicate a more aggressive cancer-you are either HER2+ or HER2-.

I would appreciate feedback. Thanks...Lynne

[Lani]

http://www.medscape.com/viewarticle/568774

[mcgle]

What is the gist of this please, Lani?

Not registered, so cannot log in.

Mcgle (UK)

[Karen W]

I would be interested in knowing as well (not registered either). Lately I have been trying to find out if a higher amplification makes a difference.

Karen

[Hazel Joyce]

Hi, Lynne. My ratio is 10.5. I've been wondering about this, also. I'll be watching this thread. Good question! And welcome to the HER2 board!

If I'm reading it right, it says that the ratio is meaningless as far as prognostic value goes.

If you google "FISH ratio" and "medscape", you'll find the article and won't need to log in.

Here are the first 2 paragraphs:

January 14, 2008 (San Antonio) — Data from the largest human epidermal growth-factor-receptor-2-positive breast cancer adjuvant trial show no prognostic value of central fluorescence in situ hydridization (FISH). Presenting at the recent 30th Annual San Antonio Breast Cancer Symposium, Worta McCaskill-Stevens, MD, from the National Cancer Institute in Bethesda, Maryland, reported a benefit in disease-free survival in a cohort of patients who were not FISH positive, but who were centrally confirmed for immunohistochemistry 3 and HER2 positivity.

The researchers found that this was also the case for FISH-positive patients with lower HER2 expression (immunohistochemistry 2+). And they observed no significant interaction between HER2 gene-copy number and the relative disease-free survival benefit of trastuzumab (Herceptin, Genentech and Roche).

[Lani]

did not have worse prognoses than those with lower FISH ratios, when treated with herceptin+chemo in the adjuvant trials. Also whether or not they had polysomy (more than two copies of chromosome 17 on which her2 sits) did not make any difference in herceptin's efficacy or their prognosis.

Check with Joe as I think there is a communal log-in for her2support members for Medscape.

Hope this helped

[mcgle]

It is certainly good news for those who had chemo and herceptin, but doesn't help people like me who had neither, even though I was weakly FISH positive.

Mcgle (UK)