This is a guest
post by David Reis. If you're interested in submitting
a guest post, please contact
me.
What
is cancer? How does it develop and what treatments will
the future offer?
First it’s important to note that
cancer is made out of cells from your own body that have, so to speak,
decided
to revolt and do their own thing. Our body naturally needs to replace
itself as you wear out, and some tissues are constantly growing. On a
daily basis, we make hundreds of billions of new blood cells for
instance.
Problems arise when the body loses
its natural balance. A breast cell, say, that only is supposed to
divide
10 times undergoes a mutation that removes some of the checkpoints.
But that alone isn’t usually enough. For cancer to develop, typically
several things have to go wrong. So the breast cell loses the
restriction that prevents it from dividing more than 10 times – and
loses the
system that tells it to commit suicide (or apoptosis) if it grows too
much.
The result could be a tumor.
Still, not all cancers lead to
disease. The breast cell can grow a little bit then stop. Or it can
start growing abnormally but trigger the body’s immune response which
either
wipes it out or stops it from growing further.
It keeps growing. Things have gotten a little better now than they used to in some situations. In breast cancer especially genetic tests can indicate important information that can guide treatment. In our example, tests indicate that the cancer has an abnormally high levels of the HER2 receptor. This receptor is involved in signaling the cell to grow. 50 years ago that would have been a very bad thing. Now it’s not as bad because we have a treatment, Herceptin, which is a monoclonal antibody specifically to that receptor.
Even then problems arise. Remember,
cancer is made of normal
cells. More than just cancerous cells express
HER receptors – some research has indicated that, among other places, it
is in
the heart. Herceptin, despite being a powerful
treatment, does indeed have some cardiac toxicity issues. The dream of cancer therapy is to
find something that only goes wrong in cancer cells and target just
that. Failing that, to target something that only
harms cancer cells and has minimal side effects to regular cells.
We’re getting better. Take
Gleevec, for instance. It was designed to inhibit the
Bcr-Abl fusion
product which is made by cancerous cells.
The clinical trials that led to its approval had incredibly
impressive
results – if I recall correctly, in one, every person who took Gleevec,
except
for one, had significant tumor shrinkage. Yet we still have a long way to go.
David is a student who loves biotechnology. He blogs about medical
topics at Health
and Life and suggests that you check out his Weekly
Pharma News Update which covers the week's most important news items
relating to the pharmaceutical industry.
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