A human tumour model.

An approach to the management of patients with large (greater than 4 cm) operable breast cancers is described. The conventional sequence of mastectomy followed by systemic therapy is reversed, allowing accurate measurements of response to individual forms of endocrine therapy or chemotherapy. Such a method not only permits individual selection of appropriate systemic therapy, but also allows clinical response to be related to histological and biochemical tumour parameters. A response was observed in eleven of twenty-three patients to endocrine treatment and in twelve of thirteen to combination chemotherapy. In five of the latter the response was histologically complete.