Chemotherapy is of significant benefit to patients with advanced breast cancer, as measured by tumor regression and increased survival. Yet these tumor regressions are short-lived, and the patient survival benefit is measured in terms of months. This relative refractoriness is due either to drug resistance or to what is called "kinetic" resistance. Kinetic resistance implies large numbers of cells and long doubling times. Experimentally, surgery combined with chemotherapy offers the best chance of cure of several solid tumors in animals. Several clinical trials in combined surgery and chemotherapy indicating a markedly favorable effect of this approach are in progress. This suggests that, as in the animal systems, kinetic resistance can be overcome by the combined-modality approach. The response to endocrine manipulation can be predicted by estrogen receptors. Clinical trials to combine chemotherapy, surgery and hormonal treatment are under way.