Cutting-Edge Breast Cancer Therapy
Hitting the Target continued...
Hormonal cancer medications even work as preventative medicine:
the FDA has recently approved the use of Tamoxifen in women who don’t yet have
breast cancer but are at high risk of developing it within a few years.
ER and PR positive cancers aren’t the only targets. Some
cancers, instead, have particularly high levels of a protein called HER2. The
drug Herceptin, a monoclonal antibody, attacks this protein and effectively
fights the cancer. Herceptin has proven so useful that it’s being moved earlier
and earlier in the treatment regimen; several studies have shown the Herceptin
is highly effective (when combined with a cancer drug called Navalbene) in
women with early breast cancer even before surgery.
And experts predict that these targeted therapies are just the
beginning. "There's much more beyond HER2 and ER-PR status," says
Winer. "The hope is that we'll be able to identify a greater number of
subtypes of breast cancer, and ... we'll have a much clearer sense of the
benefits of different kinds of treatments. At the same time, that information
is going to allow us to develop new and more targeted treatments."
Search and Destroy
One of the most promising areas of breast cancer research is
targeted therapeutics. These treatments send toxic cancer-killing agents
directly to tumor cells, avoiding the "fallout" damage to healthy cells
that happens with broad-range chemotherapies and radiation. The more that's
known about the differences in genetic makeup among cancers, the more targets
can be identified.
Researchers at the University of California San Francisco's
Comprehensive Cancer Center are in clinical trials with a new technology called
immunoliposomes, developed by researchers John Park, MD, and Christopher Benz,
"It's a molecule comprised of a lipid [fat] ball containing
a therapeutic agent, such as a chemotherapy drug," explains study leader
Joe Gray, PhD, professor of laboratory medicine. According to Gray, the
approach will use an antibody that seeks out a specific protein found only on
the surface of cancer cells. The antibody will deliver the lipid ball into the
cancer cell, where it will release its toxic contents -- the drug -- and kill