Optimizing Postoperative Chemotherapy for Breast Cancer
Name of the Trial
Phase III Randomized Study of Adjuvant Cyclophosphamide and Doxorubicin Versus Single-Agent Paclitaxel in Women With Operable Breast Cancer and 0-3 Positive Axillary Lymph Nodes (CALGB-40101). See the protocol summary.
Dr. Lawrence Shulman, Cancer and Leukemia Group B
Why This Trial Is Important
Women who undergo surgery for early-stage breast cancer are often treated with postoperative (adjuvant) chemotherapy if they are deemed to have a high risk for recurrence. High risk may be indicated by the presence of cancer in the axillary lymph nodes near the breast that contained the tumor, a large tumor, an absence of hormone receptors in the tumor cells, or other characteristics. Adjuvant chemotherapy is given in hopes of preventing or delaying recurrence of cancer and its spread to other organs.
Currently, adjuvant chemotherapy with the drugs cyclophosphamide and doxorubicin is considered standard of care. However, this combination carries with it the risk of serious long-term complications, including greater chances of heart problems and development of acute leukemia as a secondary cancer. Researchers want to know if adjuvant chemotherapy using a different drug, paclitaxel, is as effective as cyclophosphamide and doxorubicin in preventing recurrences, with fewer immediate and long-term side effects.
In this trial, women with early-stage breast cancer deemed by their doctors to be at high risk for recurrence will receive adjuvant chemotherapy with either cyclophosphamide and doxorubicin or paclitaxel given four times over an 8-week period.
"Paclitaxel has been used in breast cancer treatment for more than 20 years," said Dr. Shulman, "and it has shown equivalency to combination chemotherapy in other breast cancer settings. It hasn't been tested as a single agent, however, in women with early-stage disease.
"In this group of patients, we estimate that 80 to 85 percent will be long-term survivors, so the long-term side effects of treatment are very important considerations," added Dr. Shulman. "Paclitaxel hasn't demonstrated the long-term cardiac or leukemia risks of the doxorubicin/cyclophosphamide combination, and it usually causes fewer short-term side effects as well."
Nevertheless, treatment with paclitaxel is not without risks, Dr. Shulman noted. "One of the common side effects of paclitaxel is peripheral neuropathy, a loss of sensation or painful sensation in the extremities. Usually the neuropathy is mild and doesn't persist long, but it is a concern.
"A companion study will look at the quality of life of the women receiving these breast cancer treatments so that we will better understand their side effects," he said.