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 profound.
"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 uniformly."
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 years.
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.