Can a Tumor Get More Nutrients?
All tissues need to be continually bathed in nutrients. They get
these nutrients from the continuous flow of blood through blood
vessels. This is why blood vessels run throughout our entire
bodies. An aggressive tumor can take advantage of this fact.
Tumors can actually induce new blood vessels to form within them
so that they can receive nutrients. This process is called
angiogenesis. Make no mistake, it's eerie. The tumor cells
actually stimulate the cells lining nearby blood vessels to grow
toward them. They achieve this by sending out a signal. This
signal stimulates the cells within the nearest blood vessels to
divide 20 to 2000 times faster than usual. Due to their
unnaturally quick growth, the new blood vessels are usually not
quite normal and much less effective at carrying blood, but they
can still provide the necessary nutrients to the tumor.
All tumors consisting of more than about one million cells have
reached a point where they must achieve angiogenesis. Otherwise,
the tumor will not have enough nutrients to continue growing and
will stay the same size confined to that location. Therefore,
many researchers have focused their efforts the area of
angiogenesis.
It is hoped that scientists will find a way to stop the process
of tumor angiogenesis. If a tumor's growth could be halted it
would essentially become harmless. A tumor smaller than a pea
would most likely not even be noticed - and would probably not
have any harmful effects on the individual (although this can
depend on its location). Even in a tumor that had progressed to
a larger size, halting angiogenesis might halt its growth and
would help prevent it from spreading. This would be incredibly
beneficial to a patient diagnosed with cancer. A tumor's growth
could be halted and then if possible, it could be surgically
removed, or eradicated by chemotherapy.