Time trends in systemic adjuvant treatment for node-negative breast cancer

Purpose: We conducted a population-based study in Quebec, Canada, to assess longitudinal changes in systemic adjuvant therapy for node-negative breast cancer. Materials and Methods: A stratified random sample was selected among women with newly diagnosed node-negative breast cancer in 1988, 1991, and 1993, I nformation on the patient, her tumor, source of care, and treatment wets ab stracted from medical charts, Patients were classified as being at minimal, moderate, or high risk of recurrence on the basis of criteria proposed at the 4th International Conference on Adjuvant Therapy of Primary Breast Canc er (St. Gallen, Switzerland, 1992), and systemic adjuvant treatment receive d was dichotomized as being consistent or not consistent with consensus rec ommendations. Results: Overall, 1,578 cases of invasive breast carcinoma were reviewed. T he proportion of patients who were given hormonal or cytotoxic treatment in creased from 51.7% to 73.1% from 1988 to 1993. Virtually all women at minim al risk were treated in 1991 and 1993 according to the consensus statement. The proportions of women so treated were 75.0% and 65.4% in the moderate- and high risk categories, respectively, in 1991. In 1993, these proportions were 71.4% and 67.0%, respectively. Omission of chemotherapy, especially i n high-risk women with estrogen receptor negative tumors who were 50 to 69 years of age, was the most frequent inconsistency with guidelines. Conclusion: Systemic adjuvant therapy for node-negative breast cancer has g ained acceptance. Better understanding of the decision-making process, of t he perception of the risks and benefits involved, and of the impact of alte rnative strategies for the dissemination of consensus recommendations are n eeded to promote the use of chemotherapy in specific categories of women wh o are at high risk of recurrence, J Clin Oncol 17:1458-1464. (C) 1999 by Am erican Society of Clinical Oncology.