Abstract
Peripheral lymphocyte counts were performed on 41 patients with advanced breast cancer, before starting treatment with oestrogens or androgens. Patients were seen at monthly intervals, and the response to treatment was independently assessed, using the criteria of the British Breast Group. In the patients treated with oestrogens and androgens, the successful responders were found to have significantly higher pre-treatment peripheral lymphocyte counts than the intermediate responders and failures. It is suggested that pre-treatment peripheral lymphocyte counts may have a prognostic value in assessing potential response to hormone therapy in patients with breast cancer.