Two cycles of high-dose chemotherapy (versus only one cycle) followed by an autologous stem cell transplant appear to improve anti-cancer response rates in patients with advanced breast cancer, according to a recent article published in
Biology of Blood and Bone Marrow Transplantation. Moreover, in this clinical trial there were no treatment related patient deaths.
Optimal treatment for breast cancer depends on the stage of cancer, or the extent of disease at the time of diagnosis. Advanced or metastatic breast cancer refers to cancer that has spread from its site of origin to distant sites in the body. Treatment for patients with this stage of disease typically consists of combination chemotherapy, hormonal therapy and/or radiation therapy to relieve symptoms and prolong survival. The use of high-dose chemotherapy and stem cell transplant (SCT) is a controversial approach in the treatment of advanced breast cancer, even though some studies have shown that this approach produces better outcomes than conventional chemotherapy. Regardless of treatment modality, the majority of women with advanced breast cancer have a cancer recurrence following therapy.
High-dose chemotherapy kills more cancer cells than standard chemotherapy; however, it also causes more damage to the blood cells, particularly those in the bone marrow. A stem cell transplant is a procedure that remedies this problem by replacing the stem cells that are destroyed by high-dose chemotherapy with healthy stem cells, thereby allowing more rapid recovery and production of the red blood cells, white blood cells, and platelets that the body needs.
Less than 50% of patients with metastatic breast cancer achieve complete disappearance of cancer following a single cycle of high-dose chemotherapy. Since patients who do not achieve a complete disappearance of their cancer following therapy cannot be cured, researchers have attempted to improve upon complete responses by utilizing 2 cycles of high-dose chemotherapy prior to stem cell transplant.
Researchers from the City of Hope Cancer Center recently evaluated the efficacy and safety of two cycles of high-dose chemotherapy in 29 patients with stage IV breast cancer. All patients were treated with 2 cycles of melphalan and cisplatin, followed by an autologous stem cell transplant. There were no treatment related deaths. Following 2 cycles of therapy, 55% of patients experienced a complete anti-cancer response, compared to only 28% following the first cycle. Approximately 4.6 years following treatment, 11 patients were alive. Five years following treatment, the estimated cancer-free survival is 19% and overall survival is 39%.
These results indicate that this treatment regimen is safe and may improve survival for patients with metastatic breast cancer. Patients with metastatic breast cancer may wish to talk with their doctor about the risks and benefits of high-dose therapy or of participating in a clinical trial evaluating other new treatment options. Two sources of information about ongoing clinical trials that can be discussed with a doctor include comprehensive, easy-to-use services provided by the National Cancer Institute (
Biology of Blood and Bone Marrow Transplantation, Vol 7, No 5, 2001)