Remember; over the years incorrectly using the term "cancer" has led to
far, far, far, far too many ferrets not receiving curative surgeries or
helpful treatments due to folks panicking and putting down ferrets way
too early or sometimes completely needlessly.  Luckily, there seem to be
far fewer people who assume the worst about tumors now, so this post went
9 months without being re-used this time around.
 
 Date:    Thu, 28 Mar 2002 13:26:40 -0500
 From:    Sukie Crandall <[log in to unmask]>
 Subject: BW and SC FHL golden oldie: what is or is not "cancer"
 
>The thread on this is pretty good, and both Sukie and Stephanie have very
>valid points.  The terminology of neoplasms can be confusing, and I'm
>sure even vets can be confused from time to time.
>
>The proper term for what you are talking about is neoplasm (or literally
>"new growth).  For one reason or another, a clone of cells begins to grow
>uninhibited by normal substances or mechanisms.  The word "tumor" may be
>technically correct, but it is actually non-specific - tumor is Latin for
>a swelling, but it could also be an abscess, or anything else that causes
>swelling - so I try to stay away from it.
>
>Now this neoplasm may be benign - without the ability for cells to detach
>into the bloodstream or lymph, move to another tissue, and set up shop -
>or malignant (where they can do this.) The process of microscopic piece
>of a tumor moving to another organ is called metastasis.
>
>Metastasis is the hallmark of malignancy.  The worst tumors have the
>propensity to go anywhere and start growing (like lymphoma).  However,
>we can recognize malignant tumors even before they metastasize, often
>by characteristic features seen under the microscope.
>
>Adrenal carcinomas (malignant adrenal tumors) are interesting neoplasms.
>Although they possess the ability to metastasize, only a small number do,
>and usually only late in the course of disease.  It is likely that they
>do metastasize a lot, but have trouble gaining a foothold in distant
>tissues, so it takes a long time and many attempts if they ever truly
>metastasize.
>
>Insulinomas are generally not malignant tumors as they only very rarely
>metastasize.  The presence of multiple tumors in the same organ over
>time is not metastasis.  We do not understand the mechanism behind the
>generation of these tumors, and when we do surgery to remove them, we
>really are only treating the end point of this process, without address
>the cause.  Thus it is really no surprise that the rate of recurrence is
>about 40% within 10 months.
>
>With kindest regards,
>Bruce Williams, DVM
 
 
[Part two: addendum to above]
 
Treat this as an supporting document to Bruce William's excellent post
above taken from FHL digest 348.  I especially liked his providing the
direct translation of "tumor" as "swelling", and his explanation that
not all growths which can metastasize do so readily.
 
These definitions are combined ones from medical, veterinary, and biology
dictionaries, but emphases are mine and i am willing to be corrected if I
blew it...
 
Important Note: some more recent dictionaries don't even include the term
cancer, and I have heard vets who won't use it due to the widespread
confusion out there, and even some vets who won't use "tumor' due to too
many assuming that any tumor is malignant.
 
Tumor: ANY abnormal mass resulting from the excessive multiplication
of cells; a swelling, especially that resulting from the growth of new
tissue; a neoplasm
 
cancer: Any MALIGNANT TUMOR; carcinoma; a carcinoma or sarcoma
 
malignant: pertaining to or denoting progressive growth of CERTAIN tumors
which if not checked by treatment spread to DISTANT sites, terminating in
death; a tendency to progress in virulence, cancer is the best known
example
 
benign: not malignant, as in CERTAIN TUMORS; not recurrent, favorable for
recovery
 
neoplasm: a tumor; ANY new growth, specifically one in which cell
multiplication is uncontrolled and progressive, neoplasms may be benign
or malignant
 
(Subsets from Saunders:
neoplasm, benign: a neoplasm having none of the characteristics of a
malignant neoplasm (see below), i.e.it grows SLOWLY, expands WITHOUT
METASTASIS, and USUALLY does not reoccur [See the notes of Dr. Bruce
Williams above in relation to why LOCAL reoccurance is NOT metastasis.]
 
neoplasm, malignant: a neoplasm with the characteristics of anaplasia,
invasiveness and metastasis
 
There are several other subsets of neoplasia in this dictionary.
 
metastasis: the transfer or disease from one organ or part to another NOT
DIRECTLY CONNECTED WITH IT
 
anaplasia: loss of differentiation of cells
 
Those who have the _Saunder's Comprehensive Veterinary Dictionary_ will
find that this resource often provides details beyond these bare-bones
descriptions.
[Posted in FML issue 4057]