Hello everyone, I'm James DeGregori.
I'm a professor at the University of Colorado Cancer Center and I'll be
talking about how we can connect aging and cancer through the lens of
evolution and how this alternative understanding of
the formation of cancers can be beneficial to both prevention and treatment.
One thing that most of us will appreciate is that
about 90 percent of cancers develop after the age of 50.
The real question is why?
For the conventional point of view,
and probably the view that you've read about in your textbooks this is
really requires time, cell divisions, exposures such as from
smoking and our underlying genetics and all of
these different factors basically contribute to
one major causative factor and that is mutations.
The conventional point of view holds that it's the mutations that drive cancers and there's
been this classic understanding of cancer evolution for
the last 50 or plus years whereby cancer arises by clonal selection.
We start with an initiating mutation,
what we would call an oncogenic mutation,
it happens in a single cell shown here in red and this will then lead to the expansion of
that clone because that mutation is thought to
confer some advantage to the cell relative to its peers.
After that clone expands,
you're going to increase the odds of the next mutation which is
shown with a little green quadrant which then provides
a further advantage allowing that clone to competitively
expand even beyond the initial red clone and so forth.
From this understanding we can appreciate how
a cancer can accumulate multiple mutations within
the same clone that provide
the different characteristics or what we call phenotypes of the cancer,
and it's these characteristics of the cancer that of
course cause so much damage and death to humans.