The Prognostic Value of Oestrogen Receptors in Breast Cancer*

Survival data for 2006 women who had oestrogen receptor assay carried out on primary breast cancer tissue between 1976 and 1982 are presented. There was a significant trend to shorter survival in patients with low ER levels than in those with high ER levels (P < 0.01). This trend was evident in both pre‐ and post‐menopausal women. The point of maximum discrimination between prognostic groups occurred at 8 fm in premenopausal women and the four year survival rates of patients above and below this level were 84% and 48%, respectively. In post‐menopausal women, maximum discrimination occurred at 90 fm, and the four year survival rate above and below this level were 82% and 64%, respectively.