[Histonet] Re: HER2 fixation time

Kari Bradshaw kbradshaw <@t> lcpath.com
Thu Jan 24 11:14:49 CST 2008

I agree fully.  We have two VIP's.  One is set Friday night to process
overnight and the tissue sits in paraffin until Monday morning.  The
other processor is set Saturday morning to run an overnight process and
those tissues sit in paraffin until Monday morning as well.

Kari Bradshaw
Anatomic Pathology Manager
Lower Columbia Pathologists
1217 14th Ave
Longview, WA 98632
kbradshaw <@t> lcpath.com

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Rene J
Sent: Thursday, January 24, 2008 8:47 AM
To: ancillarypath <@t> mac.com; histonet <@t> lists.utsouthwestern.edu
Subject: Re: [Histonet] Re: HER2 fixation time

Not if you set the instrument to start EXACTLY when you want. You will
have the tissues in melted paraffin more time, or you can extend the
dehydration times. You can do a lot of things all preventing longer
fixation in NBF. Modern TP are very flexible instruments and I have no
data that reflects any deleterious effects for the tissues' reactive
qualities or sectioning characteristics after being in melted paraffin
for long periods of time. 
  René J.

ancillarypath <@t> mac.com wrote:
  I agree with Rich, and it's good to hear that some colleagues have
started their own mode of cross-validation.

If you choose to deviate from the upper fixation limit of 48 hours, you
will ONLY be at default if you do not have evidence (with
documentation) that raising the upper fixation limits to 72 or 96 hours
has no detrimental effects on the results. The CAP will eventually
increase the upper limit to 72 (or hopefully 96) hours once there is
solid evidence that is ok to do so.

Rene's suggestion to put the instrument on delay is not a valid
solution. As long as the tissue is sitting in formalin in the instrument
while it's on delay, it's still being fixed. This issue was discussed at
the ASCO/CAP meeting.


Hadi Yaziji, M.D., Medical Director
Vitro Molecular Laboratories,
President, Ancillary Pathways
7000 SW 62nd Avenue, Suite Penthouse-C
Miami, FL 33143
Tel 305.740.4440
Fax 786.513.0175

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Message: 18
Date: Thu, 24 Jan 2008 09:57:05 -0500
From: "Richard Cartun" 
Subject: Re: [Histonet] HER2neu Fixation times
To: "Ramona Turner" ,

Message-ID: <479860F2020000770000A527 <@t> gwmail4.harthosp.org>
Content-Type: text/plain; charset=US-ASCII

Personally, I would not initiate any drastic changes at this point. 
Keep in mind that these are guidelines; however, you must validate your
testing if you are going to follow other fixation guidelines. I think
everyone knowledgeable with this issue knows that the problem is with
underfixation, not overfixation. I recently pulled tumor out of formalin
after 8 months of fixation and the IHC was still "3+" and the FISH
showed beautiful amplification (ratio of 10.0). I hope that once the
scientific evidence is evaluated, these guidelines will be changed.
Major expense is being incurred here unnecessarily. How is your
concordance between IHC and FISH for the detection of HER2? If it's not
broken, don't try to fix it. Our "ad-hoc" committee on IHC
standardization is meeting in Santa Barbara on Sunday and I hope this
issue will be discussed.


Richard W. Cartun, Ph.D.
Director, Immunopathology & Histology
Assistant Director, Anatomic Pathology
Hartford Hospital
80 Seymour Street
Hartford, CT 06102
(860) 545-1596
(860) 545-0174 Fax

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