[Histonet] Fw: ER Clones

[Bryan Hewlett]

Lena,

I suspect that ER clone 6F11 will prove to be the most popular.
Why ? Check out the following paper; Bevitt D J et al. J Pathol. 183:
228-232 (1997).

Yes, there may be significant changes in ER staining between core biopsy and
excisional specimen.
Particularly if you subscribe to the myth that small biopsies do not need to
fix as long as larger specimens!!

If your core biopsies are fixed in NBF for less than 8-12 hours and the
later excisional specimens are breadloafed and properly fixed for a minimum
of 24 hours. When the ER stains are compared, the core biopsies will show
diminished or even negative ER staining as compared to a positive excisional
specimen.
We have consistently seen this effect since we started to perform ER IHC
over 15 years ago. Experiments with tissues and cell lines expressing ER,
using timed fixation in NBF for periods ranging from 1 hour to 3 weeks
confirmed for us that 24 hours should be the minimum fixation time. We
consider that ER and PgR staining seems to stabilize at a fixation time of
about 12 hours, with small gains up to 24 hours. For fixation times between
24 hours and 3 weeks, no fall of in immunoreactivity was noticed with either
clone 1D5 or 6F11. However, under similar experimental conditions, HER2 IHC
required a minimum of 16-24 hours fixation to stabilize. Shorter times
always produced diminished staining intensity, with times less than 6-8
hours resulting in a preponderance of negative results. Checking by FISH,
those HER2 IHC negative core biopsies that had later excision specimens
positive for HER2 IHC, confirmed the false negativity!

There was a recent paper which confirmed our findings for ER. Tell your
pathologist to check the following;
Neal S. Goldstein, et al. Minimum formalin fixation time for consistent
estrogen receptor immunohistochemical staining of invasive breast carcinoma.
Am J Clin Pathol. 120(1), 86-92, July 2003.


Regards,

Bryan

Bryan Hewlett
Technical Consultant,
Quality Management Program- Laboratory Services
Ontario, Canada



----- Original Message -----
From: "lena spencer" <lenaspencer <@t> insightbb.com>
To: "HistoNet Server" <histonet <@t> pathology.swmed.edu>
Sent: Tuesday, September 30, 2003 9:26 PM
Subject: [Histonet] Fw: ER Clones


>
> ----- Original Message -----
> From: "lena spencer" <lenaspencer <@t> insightbb.com>
> To: <histonet-request <@t> lists.utsouthwestern.edu>
> Sent: Tuesday, September 30, 2003 7:45 PM
> Subject: ER Clones
>
>
> > Hi All:
> > I have another question from my Pathologist.  By the way he was so
> impressed
> > with your response to my last question on his behalf  that he sees this
> > forum as being an important link within the histology community.
> > His question:
> > Do you prefer one ER clone, if so which clone do you prefer and why?
For
> > use on an automated platform. Also,  do you see significant changes in
> your
> > ER staining from the core biopsy to the excisional specimen.  How does
> > fixation change the staining results of your preferred ER clone?
> > Thanks in advance for your response.
> > Lena
> >
>
>
>
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