The Significance of Hormone Receptors to Predict the Endocrine Responsiveness of Human Breast Cancer

Abstract

The paper reviews clinical data on the correlation between the response of human breast cancer to endocrine therapy and the tumour cell content of receptors of e.g. oestrogen (OeR), progesterone (PgR), androgens (AR) and the epidermal growth factor (EGFR). In advanced disease there is a well established correlation betweeen OeR content and the rate of objective response to all types of endocrine therapy. However, if selection of first-line salvage therapy based on OeR status will result in prolonged survival or improved quality of life remains controversial. Assays of PgR, AR, and EGFR—in addition to OeR—increase the predictive ability but no study has been able to define an entirely unresponsive subgroup of patients on the basis of receptor status. In the adjuvant setting conflicting relationships have been reported. Some authors have found a benefit with tamoxifen also among OeR negative patients whereas others have concluded that adjuvant tamoxifen is ineffective in such patients. Prospective randomized trials are warranted to further assess the predictive value of hormone receptors, particularly in view of the increased frequency of thrombotic events and endometrial cancer associated with long-term adjuvant tamoxifen.

Key Words:

• Breast cancer
• hormone receptors
• endocrine therapy
• epidermal growth factor