One therapy
now in development at Dr. Schiller's institution would subvert the process
used by cancer cells to grow faster than normal cells.
Telomeres, which
are bits of DNA that cap the end of all mammalian chromosomes, grow shorter
as healthy cells divide -- eventually becoming so short that the cell dies.
But cancer cells
contain an enzyme, called telomerase, which adds DNA back onto the telomeres
to enable the cells to go on dividing. Drugs now in development will inhibit
the production of telomerase, Dr. Schiller said, and this line of research
could benefit all cancer treatments, not just lung cancer.
Pre-menopausal
women have the worst survival rate of lung cancer.
Research also
continues on drugs to block the formation of the new blood vessels required
for tumor growth, known as angiogenesis. Clinical trials are under way
on drugs that block the hormone -- vascular endothelial growth factor --
which causes this process.
One such randomized
trial in lung cancer patients showed increased survival rates, Dr. Schiller
said. "Again, we may have a small step forward in terms of lung cancer."
Vaccine development
is another continuing research area, she said. Its aim is to teach the
patient's immune system to fight cancer. Although such research has been
ongoing for decades, in the last five or 10 years gains have been made
in developing more tumor-specific and easier-to-manufacture vaccines.
Personalized
medicine is the way of the future, Dr. Schiller said.
Investigators
also are building on research related to other cancers, particularly breast
cancer, said Jill Siegfried, PhD, professor and vice chair of pharmacology
at the University of Pittsburgh School of Medicine. Estrogen, which is
known to enhance the growth of pre-cancerous and cancerous breast cells,
is suspected of playing a similar role in lung cancer.
Researchers
also determined that pre-menopausal women with lung cancer, those with
the highest level of estrogen, have the worst survival rate of any group,
Dr. Siegfried said. This concept may play a role in the fact that women
who have never smoked have twice the risk of developing lung cancer as
do men -- although men also have some circulatory levels of estrogen that
increase with older age, she said, and the hormone is found in their tumors
as well.
With this connection
in mind, Dr. Siegfried's lab is looking at anti-estrogen treatments and
their effect on lung tumors.
The thought
is that aromatase inhibitors, developed primarily for fighting breast cancer,
might have a place in lung cancer treatment.
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Copyright
2007 by United Press International.
All rights reserved.
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