Hi,
I'm kind of behind on my e-mail, so I'm not sure if you already have an 
answer to your questions, but here goes:

1.  Depending on your local regulations, surgical slides must be disposed 
of as glass waste.  Medical glass waste is never acceptable for 
recycling, primarily from the gross-out factor of feeding babies food 
from jars that used to be covered in blood and body parts.  The dumpster 
would not be appropriate.  Biohazard sharps waste would cover liability, 
but might be overkill.  However, in the absence of another suitable 
method of disposal, that is how we dispose of ours.

2.  In theory, yes.  What kind of stained slides did you have in mind?  
If you mean H&E's, there was a paper published September 16, 1998 in the 
Journal of the National Cancer Institute, Vol. 90, No. 19, pp 1361-1370.  
"erbB-2 and Response to Doxorubicin in Patients With Axillary Lymph 
Node-Positive, Hormone Receptor-Negative Breast Cancer" by Soonmyung Paik 
et. al.  In this paper, the authors describe using archived H&E sections 
for erbB-2 immunohistochemistry with great success.  If you mean to use 
slides previously stained unsuccessfully for her2neu, I would be wary 
because of possible blocking of the epitope sites. 

3.  As far as keeping blocks, how does keeping them longer than the 
required minimum time increase your liability?  I must admit to being 
somewhat biased about this, because such rapid destruction of patient 
material makes retrospective studies nearly impossible, and can even 
compromise patient care in the case of relapse/recurrence of cancers.  
Many, many cancers recur well after that 5-year time frame, and if the 
original tumor is no longer available for review, or worse, even the 
H&E's are gone after 10 years, it can be extremely difficult to determine 
if the current tumor represents a new primary, or a recurrence of the 
original disease.  In the paper cited above, the reason they ran erbB-2 
on H&E slides is because most of the blocks had been discarded on the 
patients enrolled into their clinical trial.  I can imagine that if you 
are a patient enrolled in such a clinical trial, it must be very 
frustrating to have the entire study jeopardized because of issues like 
this.  So, I guess you know where I stand on this topic.  I know there 
are problems and costs involved in long-term storage, but I cast my vote 
in favor of retaining material as long as possible.

>Three questions:
>
>1. What is the correct(legal) way to dispose of dated surgical slides?
>(dumpster or biohazard)
>
>
>2. Is it possible to stain for her2neu on previously stained slides. Not
>the blocks!
>
>
>3. What is the general consensus out there on surgical slide and block
>storage. Legally blocks must be kept 5 years and slides 10 years. I
>understand keeping them over this required time increases your
>liability, but I have some stubborn pathologists wanting to keep them
>7-10 years. Any info would be helpful.
>
>Thanks.
>
>
>
>


Phyllis Davie
Clinical Laboratory Supervisor
PhenoPath Laboratories
Seattle, WA
pdavie@phenopath.com
(206)374-9009  phone
(206)374-9009  fax