Doctors in the UK have begun human trials
for a vaccine designed to seek and destroy
cancerous tumors. So what does that mean?
Over the past several decades, doctors have
been experimenting with a type of cancer treatment
called immunotherapy. The idea behind immunotherapy
is pretty simple. The goal is to train a cancer
patient’s immune system to fight off cancer
cells. But it’s much easier said than done.
For one thing, cancer patients often have
a suppressed immune system. And for another,
their defense mechanisms might not even recognize
cancer as a threat. That’s where this vaccine,
developed by scientists at the Guy’s and
St. Thomas’s Biomedical Research Centre
in London, comes in.
A vaccine’s job is to introduce the body
to antigens, which are molecules that instigate
an immune response. Typically, a vaccine will
contain a weak or deactivated version of the
disease it’s meant to protect against.
When you get a vaccine, your immune system
fights off the weakened illness, which is
usually a virus or type of bacteria. Your
immune system makes a record of the antigen
so that it can spring into action should that
pesky disease show up again.
We already have some vaccines that are effective
in preventing diseases that can lead to certain
types of cancer. But using a vaccine to treat
a patient’s existing cancer is a bit different.
The UK doctors used a piece of protein from
an enzyme called human telomerase reverse
transcriptase, or hTERT. This enzyme is what
allows cancer cells to divide. If all works
as it should, the vaccine will teach immune
systems to target cells with this enzyme,
leaving others untouched.
Patients in the trial will receive the vaccine
in several stages along with a low dose of
a chemotherapy drug. At a low dose, the chemotherapy
should stimulate the immune response and kick
things into gear. The study is scheduled to
last two years. If proven successful, the
vaccine will be a huge leap forward in cancer
treatment.
And this isn’t to suggest there aren’t
other revolutionary studies in immunotherapy
going on right now. But we’ll have to save
that for another episode. Be sure to visit
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