>I know that in humans, cancer is linked to genetics, smoking, alcohol, and
>even some foods.  I was wondering what makes ferrets so prone to this awful
>disease.  I am also wondering if any one is looking for measures to prevent
>cancer from happening in addition to searching for a cure once it occurs.
 
Well, I'm not a vet, but I think my specialized education more than
qualifies me to take a stab at answering this question.  I don't do cancer
research myself.  I work with protein, not DNA.  However, I've had all the
classes, so here goes.
 
First, it's not only ferrets that are susceptible to cancer.  People, cats,
rats, dogs, probably even platypuses get cancers when they get old.
Although there are many factors, both environmental and genetic, that
contribute to cancer which we do not understand, ultimately all cancers are
caused by damage to DNA.  All of us accumulate DNA damage every day that we
live.  If you're exposed to extreme radiation, you take a LOT of DNA damage.
Even if you are not exposed to any extra radiation in your life, DNA damage
still occurs from exposure to things like cosmic rays and toxins.
 
Fear not!  Your body has little things called enzymes that *repair* your
DNA.  Hooray!  (RNA is not repaired which is why HIV mutates at such a
horrific rate) Sometimes the repair mechanisms fail, or some damage just
slips through the system.  Often this does no ultimate damage to the
organism.  A lot of DNA is just not that crucial.  Sometimes, however, DNA
damage causes cells to proliferate out of control.  This is cancer.
 
As for environmental and genetic factors, a lot of our evidence comes from
epidemiology, and almost all of it is specific to human beings.  Someone
thinks of something they think might cause cancer, and they do a study.
They survey, talk to, follow, and annoy large groups of people, and look for
correlations.  For example, out of 1000 men with prostate cancer, 998 of
them owned ferrets.  Compared with 1000 men of the same age without prostate
cancer, only 50 owned ferrets.  This is a correlation, and a pretty strong
one, but it does not account for mechanism.  Many people hearing this sort
of thing would immediately drop their ferrets at the nearest shelter.
However, we are still lacking a mechanism for this correlation.  It could be
that ferrets have nothing to do with prostate cancer, and the men who own
them are getting it from the ferretone they secretly snort when no one is
looking.  Most of these epidemiological studies are conducted in an attempt
to help people prevent cancer, not to cure it.  When the epidemiologists
have done their dirty work, geneticists, molecular biologists, and
biochemists step in to try to learn more about the mechanism.
 
As a side note, I would like to add that every once in a while, someone
posts here that their Marshall Farms ferret has cancer, insulinoma, or some
other typical ferret illness.  They are making their own correlation, but
with a really small sample size.  Even if your five Marshal Farms ferrets
keel over at the age of three, and your other five non-MF ferrets live until
they are fifteen, this is only a correlation, and not a valid one.  It
doesn't prove anything because the "study" is not large enough and it is not
controlled.  Until someone does such a study with enough ferrets to
constitute a valid sample size, I will not believe the bad PR about Marshall
Farms.  I love my Marshall ferret, and I think they raise good animals.
 
In conclusion, I think it is very natural to wonder what caused the death of
a loved one.  We often think that they could have had a much longer life if
only....  However, it is difficult to second guess Mother Nature.  I haven't
actually every heard of a correlation between alcohol and cancer.
 
I'm very sorry for the loss of the ferret mentioned above, and I can
sympathize.  But she may not have lived a minute longer no matter what
anyone does.  Life isn't fair.  It could as easily been an unavoidable
cosmic ray as any environmental factor.  I'm sure she was as happy as a
ferret could be.  I know I envy my own ferrets their persistant weasel
bliss.
 
Hope I haven't bored anyone.
 
-Catherine Shaffer
[Posted in FML issue 1475]