New Approaches to Chemotherapy for Breast Cancer
From tweaking the size and timing of chemotherapy, to adjusting how it's administered, small improvements are making a big difference in women's lives.
Combination or Monotherapy?
Experts have long debated whether combination chemotherapy, a number of
drugs administered simultaneously, is more or less effective than monotherapy,
a single drug given at a time. Recent evidence suggests that it depends on the
stage of cancer.
"Clearly," Seidman tells WebMD, "combinations are superior to
single agents in adjuvant chemotherapy, which is chemotherapy following
radiation or surgery. Experts are constantly tinkering with variations in these
combinations to make them more effective and less toxic.
But in cases of metastatic breast cancer, where the cancer has already spread
to other parts of the body, Seidman points to numerous studies that indicate
that using combination therapy is no better than using single drugs in a
sequence. For instance, Seidman says that in the recent results of one study by
the Eastern Cooperative Oncology group, using Taxol and doxorubicin Adriamycin
together had no advantage over using them sequentially.
Despite the progress that's already been made, Ellis sees this as an area of
great potential. "There's a lot more work to be done on dose scheduling and
combinations," she says. But according to one theory, she says, "it's
fiddling with all these little things that's contributing most to lowering the
The Future of Chemotherapy
Doctors and researchers are developing still other approaches to breast
cancer chemotherapy. While drugs designed to prevent anti-angiogenesis
originally attracted a great deal of attention in the press and inside
pharmaceutical companies, studies have have been almost uniformly disappointing
so far. The recent research into using Avastin, an anti-angiogenesis drug, in
advanced breast cancer have not been encouraging, but further studies are
planned. Other drugs and treatments are being developed and several
institutions are looking into the possibility of a cancer vaccine.
Because of its toxicity and the harm it causes to both healthy and cancerous
cells alike, traditional chemotherapy has inherent limitations.
"Eventually, I think we'd like to get rid of chemotherapy as we know
it," says Seidman. He hopes that as more is learned about breast cancer,
experts will continue to develop more targeted approaches to systemic, or
One new approach being studied involves using liposomes, molecules that can be
artificially filled with a chemotherapy drug and inserted into the body. These
liposomes are essentially containers that carry a chemotherapy drug directly to
the tumor, sparing the rest of the body unnecessary damage.
Treatment will also become more customized as researchers better understand the
genetics of various subtypes of breast cancer. Different types of breast cancer
respond better to different treatments. Drugs such as Herceptin -- which is
designed to affect a specific type of cancer cell with high levels of the HER2
protein -- are the first new targeted medications. Researchers are also working
on developing genetic tests for cancer cells that might allow doctors to
identify the kind of cancer and thus determine a person's ideal treatment from
Seidman reports that at Memorial Sloan-Kettering, breast cancer researchers
have been studying the drugs geldanimycin and Gleevec -- the latter is
currently used to treat certain types of abdominal cancer and leukemia -- for
their targeted effects on cancer cells. Results are a ways off, but as more
precise and focused ways of attacking cancer become possible, doctors may
someday be able to stop relying on the generic, toxic chemotherapy agents that
have been used for decades.