HER2 Support Group Forums - View Single Post - her2 copy number cut-off point (by FISH) may be decreased (2.2to1.5)

Debbie L. · 03-27-2009, 07:59 PM

It has always interested me that at least in discussing Herceptin response and/or aggressiveness/prognostics, HER2 ratio by FISH doesn't offer quantitative prognostic nor predictive information. IOW, a high FISH ratio doesn't appear to mean that it's a worse prognosis nor a more-likely response to Herceptin. Yet on the lower end, we're not sure where the cut-off is, for Herceptin benefit.

That brings us to the question that I'm hearing more often lately - are we even looking at the right thing, when we look for a marker for those who can benefit from Herceptin, using HER2 by FISH or IHC? I don't know the answer of course - but neither, I suspect, does anyone else.

At present, we have only a somewhat-predictive thing - response for HER2+ to Herceptin is somewhere between 30 and 50% using current assays.

Debbie Laxague

03-27-2009, 07:59 PM	#9
Debbie L. Senior Member Join Date: Jul 2006 Posts: 463	some clue or piece is missing It has always interested me that at least in discussing Herceptin response and/or aggressiveness/prognostics, HER2 ratio by FISH doesn't offer quantitative prognostic nor predictive information. IOW, a high FISH ratio doesn't appear to mean that it's a worse prognosis nor a more-likely response to Herceptin. Yet on the lower end, we're not sure where the cut-off is, for Herceptin benefit. That brings us to the question that I'm hearing more often lately - are we even looking at the right thing, when we look for a marker for those who can benefit from Herceptin, using HER2 by FISH or IHC? I don't know the answer of course - but neither, I suspect, does anyone else. At present, we have only a somewhat-predictive thing - response for HER2+ to Herceptin is somewhere between 30 and 50% using current assays. Debbie Laxague __________________ 3/01 ~ Age 49. Occult primary announced by large (6cm) axillary node, found by my husband. 4/01 ~ Bilateral mastectomies (LMRM, R elective simple) - 1.2cm IDC was found at pathology. 5 of 11 axillary nodes positive, largest = 6cm. Stage IIIA ERPR 5%/1% (re-done later at Baylor, both negative at zero). HER2neu positive by IHC and FISH (8.89). Lymphovascular invasion, grade 3, 8/9 modified SBR. TX: Control of arm of NSABP's B-31 adjuvant Herceptin trial (no Herceptin, inducing a severe case of Herceptin-envy): A/C x 4 and Taxol x 4 q3weeks, then rads. Raging infection of entire chest after small revision of mastectomy scar after completing tx (significance unknown). Arimidex for two years, stopped after second pathology opinion. 2017: Mild and manageable lymphedema and some cognitive issues.