Previous studies have shown that women with hormone-receptor positive, early-stage breast cancer can significantly reduce their risk of cancer recurrence by taking a combination of tamoxifen and chemotherapy after surgery. New research now demonstrates that these women gain the most benefit if they start taking tamoxifen after they have finished chemotherapy, rather than at the same time.
"Many women in the United States receive tamoxifen and chemotherapy together after surgery," said Kathy S. Albain, MD, the study's lead investigator and Director, Breast Cancer Research and Co-Director, Breast Care Center at Loyola University Cardinal Bernardin Cancer Center in Chicago. "Our results show that it is best to wait until chemotherapy is finished before starting tamoxifen to obtain optimal benefit from the chemotherapy."
Eight years after enrolling in the study, women who received tamoxifen after chemotherapy were 18% more likely to survive without a cancer recurrence compared to women who received chemotherapy and tamoxifen at the same time. All women in the study were post-menopausal, had early-stage breast cancer that had spread to the lymph nodes but no further, and tumors that contained estrogen or progesterone receptors.
In the current study of 1,477 eligible women, patients were randomly selected to receive one of three therapies: tamoxifen after chemotherapy (566 patients), tamoxifen and chemotherapy simultaneously (550 patients), and tamoxifen only (361 patients).
After eight years, 67% of women who received tamoxifen after chemotherapy remained breast cancer-free, compared with 62% who received the two therapies together and 55% who received tamoxifen only. After the researchers accounted for other factors that predicted breast cancer recurrence - such as tumor size, degree of lymph node involvement, progesterone receptor status, and race - they found an 18% advantage to completing chemotherapy before starting tamoxifen versus simultaneous administration.
SOURCE:
38th Annual Meeting of the American Society of Clinical Oncology, May 18, 2002, Orlando, FL
