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Clinical practice guidelines for the care and treatment of breast cancer: adjuvant systemic therapy for node-negative breast cancer (summary of the 2001 update)
Owing to an editorial error, the recommendations of the updated clinical practice guideline concerning adjuvant systemic therapy for node-negative breast cancer were not included with the summary of the guideline published in the Jan. 23, 2001, issue of CMAJ. The recommendations appear in Table 1. [CMAJ 2001;164(4):465] This article provides a summary of changes made by the Steering Committee on Clinical Practice Guidelines for the Care and Treatment of Breast Cancer to the article "Clinical practice guidelines for the care and treatment of breast cancer: 7. Adjuvant systemic therapy for women with node-negative breast cancer" originally published in 19981 (the 2001 update can be found online. Although there are not many changes to this guideline, new studies have provided even more evidence that supports the original recommendations. The Early Breast Cancer Trialists' Collaborative Group has published further analyses of its data.2,3 This recent meta-analysis has included greater numbers of women with breast cancer and a longer follow-up than the 1990 analysis. In the earlier analysis involving over 4900 women with node-negative breast cancer who received chemotherapy, the relative risk reduction in the risk of recurrence had been 26% and the relative reduction in mortality 18%. In the recent analysis, these figures were 34% and 18% respectively among women under 50 years of age, and 28% and 23% respectively among those 5069 years old. Similarly, in the 1990 analysis involving over 12 000 women with node-negative disease who had received tamoxifen, the relative reduction in the risk of recurrence had been 25% and the relative reduction in mortality 17%. In the recent analysis these figures were 49% and 25% respectively among women with node-negative estrogen-receptorpositive disease who had received 5 years of tamoxifen. The steering committee's original guideline had recommended the use of either Adriamycin plus cyclophosphamide (AC) chemotherapy or cyclophosphamide, methotrexate and fluorouracil (CMF) chemotherapy in women with high-risk, node-negative breast cancer on the basis of extrapolated results from clinical trials involving women with node-positive disease. The updated guideline contains information from a recent large trial by the National Surgical Adjuvant Breast and Bowel Project (NSABP) in which these 2 chemotherapy regimens were compared in women with node-negative breast cancer that was estrogen-receptor negative.4 The survival rate at 5 years was about 90% in both treatment groups. Previously it was unclear whether there was a role for tamoxifen in the treatment of estrogen-receptornegative breast cancer. The new NSABP trial also compared tamoxifen plus chemotherapy with chemotherapy alone.4 The survival rate at 5 years (about 90%) did not differ between the 2 groups. This finding indicates that there is no role for tamoxifen in the treatment of such cases. The original guideline recommended adjuvant systemic therapy in women with node-negative breast cancer at high risk of recurrence. Chemotherapy was recommended for all premenopausal women (less than 50 years of age) and for postmenopausal women (50 years of age or older) with tumours that were estrogen-receptor negative. Tamoxifen was recommended for postmenopausal women whose tumours were estrogen-receptor positive. For this last group it was suggested that patients might benefit further by the addition of chemotherapy. By and large, the updated guideline makes the same recommendations concerning systemic therapy in women with node-negative breast cancer at high risk for recurrence. However, for postmenopausal women with estrogen-receptorpositive disease, the addition of chemotherapy to tamoxifen therapy is recommended, but the increase in chemotherapy-related toxicity must be considered. Finally, whether the use of tamoxifen should be recommended in premenopausal women with estrogen-receptorpositive breast cancer following chemotherapy is unclear.
The patient version of these guidelines has also been updated and can be found online.
Competing interests: None declared. Dr. Levine is with the Cancer Care Ontario Hamilton Regional Cancer Centre, the Departments of Medicine and of Clinical Epidemiology and Biostatistics, McMaster University, and is the Buffett Taylor Chair in Breast Cancer Research, McMaster University, Hamilton, Ont. The steering committee is part of Health Canada's Canadian Breast Cancer Initiative. Correspondence to: Dr. Mark Levine, c/o Ms. Humaira Khan, Faculty of Health Sciences, McMaster University Health Sciences Centre, Rm. 2C6, 1200 Main St. W, Hamilton ON L8N 3Z5; fax 905 577-0017 References
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