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.
New Ways to Administer Chemotherapy
Ellis and Seidman also see hope in a new approach to chemotherapy called
dose density therapy, in which standard medications are administered more
frequently than in the past. Although the idea is simple, its effects appear
"For years we've been looking at dose intensity," says Seidman, which
involves administering higher doses of chemotherapy medications than usual.
"The results have been disappointingly negative, almost
Using the standard or lower doses but giving them more often looks more
promising. In addition to restricting the opportunity for cancer cells to
become resistant to drugs, dose density therapy seems to constrict the blood
supply to tumors, preventing their growth. This effect, called
anti-angiogenesis, has been the focus of a great deal of research for
One recent study conducted by the Cancer and Leukemia Group B (CALGB) -- a
research group sponsored by the National Cancer Society -- found that using
dose density therapy could have dramatic effects. In women with breast cancer
that had spread to the lymph nodes, researchers found that after surgical
removal of the tumor, dose dense chemotherapy with various combinations of
standard drugs -- Adriamycin, Taxol, and Cytoxan -- could reduce the risk of
recurrence by 26%. Frequent dosing didn't cause a greater number of side
effects than traditional therapy, although the drug Neupogen was used to
prevent the chemotherapy from causing neutropenia, a drop in the number of
white blood cells. Seidman is currently leading another study for the CALGB of
dose density therapy in 500 women with metastatic cancer using Taxol. He
believes he will have results soon.
Ellis is optimistic about one variation of this approach called metronomic
therapy, which focuses on making dose size tolerable and administering medicine
orally when possible. Trials at Fred Hutchinson are going on now.
Another recent shift in treatment has been the increasing emphasis on
neoadjuvant chemotherapy, the use of anti-cancer medications before surgery or
radiation. While neoadjuvant therapy has not been shown to lengthen cancer
patients' lives, it seems to have other benefits. For one, it decreases the
odds that a patient will undergo a mastectomy and increases the odds that she
will have less aggressive, breast-conserving surgery.
Of course, the significance of new medications shouldn't be underestimated.
"One of the biggest changes we've had in chemotherapy is that we have new
agents for breast cancer," says Ellis. Among them are Navelbine, Taxol, and
Taxotere, which all work by disrupting the growth of cancer cells. While
they've proved effective in women fighting advanced breast cancer, they are
also currently being studied for use in early breast cancer.
Outside of chemotherapy in the strict sense, hormonal treatments are also
having an impact. One of the most exciting developments, says Ellis, has been
the development of aromatase inhibitors, including Arimidex, Femara, and
Aromasin and the monoclonal antibody, Herceptin.