Combined chemo-hormonal therapy in breast cancer: a hypothesis.

Results of treatment for advanced breast cancer have plateaued indicating the need for new treatment approaches. One such approach, combined endocrine therapy and cytotoxic chemotherapy, has had limited success in current clinical trials. This lack of synergism could be due to the effect of endocrine therapy on tumor cell kinetics, which could inhibit the activity of the cytotoxic drug. Proper sequencing of the two treatment modalities may increase the therapeutic ratio.