Effect of time and therapy on the hormone receptor status of breast carcinomas.

To determine whether the hormone receptor status of a breast carcinoma can change during the course of the disease or its treatment, the results of estrogen receptor assays in two or more biopsy specimens from 68 patients were examined; progesterone receptors had been assayed in approximately 40% of the specimens, too few to permit statistical analysis of the results. The patients fell into four groups: A, those with at least two primary breast carcinomas, and B to D, those with at least two breast carcinomas, at least one of which was a secondary tumour (usually of lymph node, skin or soft tissue) excised on the same occasion (B), 1 to 76 months later, after no intervening therapy (C), or 3 to 73 months later, after intervening chemotherapy (usually adjuvant), regional irradiation or hormonal therapy, or a combination of these (D). The small numbers in the subgroups precluded statistical analysis of the results for groups A and D. The degree of concordance of the hormone receptor status of the primary and secondary tumours in groups B and C was significant, at 87% (P less than 0.01) and 80% (P congruent to 0.01) respectively. Chemotherapy and regional irradiation did not appear to reduce the degree of concordance. All primary tumours in the same breast removed on the same occasion had the same hormone receptor status, but bilateral primary tumours appeared to have an independent status, which suggests that local tissue factors, as well as the systemic hormonal environment, play a role in establishing the hormone receptor status of breast carcinomas.