RESUMO
This prospective clinical trial was designed to assess the impact of adjuvant chemotherapy in women with rapidly proliferating node-negative breast cancer. This group has been predicted to have a 5-year disease-free survival (DFS) of 70% without adjuvant chemotherapy. In this study, 449 women with rapidly proliferating breast cancer (91% measured by S-phase fraction and 9% by histochemistry) received adjuvant chemotherapy with doxorubicin/cyclophosphamide (AC) plus tamoxifen for estrogen receptor-positive or progesterone receptor-positive cancer. The 5-year DFS was 90% (+/- 2%) and the 5-year overall survival was 94% (+/- 1%). At a median follow-up of 62 months, the strategy of administering 6 cycles of AC to women with T2 N0 cancer and 3 cycles in those with smaller T1 N0 cancers appeared to eliminate tumor size as a potential prognostic factor. Adjuvant chemotherapy with AC appears effective in reducing recurrence rates for women with rapidly proliferating node-negative breast cancer.