DNA ploidy reports on breast CA

From: DAHL CHASE DIAGNOSTIC SERVICES (dcdsflow@mint.net)
Date: Mon Jun 07 1999 - 08:19:54 EST


Dear clinical Flow experts, we need your help!
For the past months we have been trying to research the current literature
and develop a more meaningful report on breast CA cases (node negative
only).  Well, to say the least, we are more confused than before since there
still does not seem to be any significant progress from the 93 consensus
report.  In the past we have signed out our cases basically as good
prognosis (diploid and low SPF with less than 7%), intermediate prognosis
(diploid with SPF more than 7% or aneuploid with less than 12%), and poor
prognosis (aneuploid with SPF of 12% or higher or hypertetraploid) according
to the Kallioniemi paper of 1988.  We have also verified these cutoff points
for the s-phase fractions with our own laboratory data.  However, I think
the recent "consensus" is that SPF seems to be more important than the
ploidy and more emphasis should be placed on this regarding the
interpretation to the physician.
So here are my questions:

1.  What are the different prognostic groups?  Is it really just the SPF
which matters or do you still report out aneuploid as a bad prognostic factor?

2.  If you do report both, which one do you weigh heavier (SPF or ploidy)?

3.  Which cutoff values for the SPF are you using.  We established a mean
SPF of 40 diploid (paraffin-embedded) and 40 aneuploid tumors and added
2SD's to the mean as a cutoff value.  For instance, for the aneuploid tumors
the mean was 6.6% with +/- 2 SD's of 5.4%, so the cutoff is 12%.  Is
everything below 12% a low SPF and does this result put this patient in a
favorable group despite the aneuploidy?

4.  If ploidy matters, do the near-diploid tumors do as well as the DNA
diploid tumors?  We get excellent C.V.'s in our lab (between 1.8 and 3.0 and
we see quite a few near-diploid ones). Is hypodiploidy and hypertetraploidy
still considered worse than just plain aneuploidy?

I really would appreciate your input since we are just about to delete the
ploidy analysis on breast Ca from our flow menu.  If we don't know exactly
what it means, how is the ordering physician supposed to make sense out of
it and use our data for patient treatment?

We are looking forward to your reponses
Andrea Illingworth

Dahl-Chase Diagnostic Services/Flow Cytometry
333 State Street
Bangor, Maine 04401
(207)990-4855



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