Variations in steroid receptor status with disease stage in breast cancer

Oestrogen and progesterone receptor (ER and PgR) distribution in three clinical subgroups of 421 breast carcinomas was analysed. The groups comprised (1) early breast cancer (T1-2a, N0M0; n = 64); (2) untreated advanced fungating cancer (n = 27) and (3) advanced cancer relapsing after endocrine therapy (n = 29). Receptor distribution in each of the subgroups was compared to that of the total population. The advanced fungating group contained no ER--ve/PgR--ve tumours and the distribution was also significantly different from the total population (P less than 0.001 by Chi-squared test). The proportion of tumours in the total population that contained greater than 40 fmol/mg ER was 187/421 (44.4%). There was no significant difference between the early breast cancer group and the total population (P greater than 0.9). However, the proportion of tumours containing ER greater than 40 fmol/mg in the advanced fungating cancer group (16/27, 59.3%) was significantly higher than in the total population (P less than 0.01). This difference may be partially explained by the older age at presentation in this group. In the relapsed after endocrine therapy group only four of 29 (13.8%) contained ER greater than 40 fmol/mg which was significantly different from the total (P less than 0.001). There was a higher proportion of early breast cancers containing PgR greater than 40 fmol/mg than in the total population (P less than 0.001). There was no significant difference between PgR distribution in the advanced fungating and relapsed groups compared to the total population. The data suggest that patients presenting with advanced fungating cancer are more likely to respond to endocrine therapy than the population as a whole, and that in breast cancer that has relapsed following endocrine therapy receptor levels decrease with progression of the disease.