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Estrogen (ER) and progesterone receptors (PgR) appear to be a prerequisite to elicit a biologic response by a hormone-target organ. Current methodologies for analysis of these proteins (e.g., dextran-coated charcoal, DCC) in single-label assay (SLA) require relatively large amounts of tissue material, time and laboriousness. Therefore, we have developed for breast cancer tissue an improved dual-label assay (DLA) for simultaneous titration (by DCC) and/or characterization (by sedimentation properties) of ER and PgR on the same sample, using 125I-E2and 3H-Org 2058 as tracers. The interaction of 125I-E2with ER and plasma proteins in comparison to 3H-E2was studied in terms of specificity, time course, affinity binding and sedimentation pattern. 125I-E2bound the same molecular forms displayed by 3H-E2(9 and 3S) but with lower titers (about 1.3-fold), irrespective of the technique used, and did not bind to sex hormone-binding globulin. Simultaneous detection of 125I and 3H was achieved by use of a gamma counter plus a beta counter sequentially. ER and PgR titrations with DCC in DLA were in good agreement with those obtained with SLA, in terms of titers and Ka values. An analogous result was obtained with sucrose density gradient (SDG) analysis. Both the DLA methods were highly reproducible (CV < 8.0 %). Between the rotors available for SDG, the vertical one was preferable because of the larger number of samples processed and of less purturbation of sedimenting receptor molecules. Furthermore, a biochemical application of the method is described. In conclusion, the DLA procedure, by simplifying ER and PgR estimation, makes it possible to study, even on small tumor biopsies, the molecular properties of these proteins in relation to the clinical response of the disease.

Estrogen (ER) and progesterone (PgR) receptor content was assayed in 290 premenopausal women with primary breast cancer, in order to investigate the influence of endogenous hormones on cytoplasmic receptor concentrations throughout the menstrual cycle, subdivided into four phases of ovarian function (early and late follicular phase, early and late luteal phase). Of the total population, 231 (79.7 %) patients were ER positive and 59 (20.3 %) were ER negative; 220 (75.9 %) were PgR positive and 70 (24.1 %) were PgR negative. The percentages of positive cases were almost constant in each phase. No significant difference in mean values of ER concentration was noted throughout the cycle. Instead, the PgR concentration significantly increased from the first to the third phase (P = 0.02) and decreased from the third to the fourth phase (P = 0.01). Our results suggest that ER- and PgR- cases are homogeneously distributed and not influenced by the phase of the cycle. Moreover, they suggest that PgR measurement in the luteal phase, rather than in other phases, prevents the occurrence of false low PgR levels and, at the same time, improves its prognostic significance and response rate to endocrine therapy.

The role of int-2 oncogene amplification on the prognosis of breast cancer patients was investigated in 128 patients with node-negative primary breast cancers given first-line local-regional treatments until relapse and with a median follow-up of 65 months. Tumours had been previously characterised for oestrogen (ER) and progesterone receptor (PgR) status and proliferative activity (³H-thymidine labelling index). Amplification of the int-2 oncogene occurred in 18% of cases and was significantly related to the presence of hormone receptors and to menopausal status or age, but not to proliferative status. Patients with tumours exhibiting int-2 amplification had a lower probability of disease-free survival than patients with non-amplified tumours and frequently developed local-regional recurrence. Disease-free survival analysis, adjusted for the prognostic contribution provided by tumour size, steroid receptors and proliferative rate, indicated that the association between int-2 amplification and risk of relapse was maintained and remained constant even in the presence of the other co-variates. Interestingly, int-2 amplification was a further prognostic discriminant within subsets of patients with a putatively good (i.e., tumour size &lt;20 mm, ER⁺ and PgR⁺) or poor prognosis (i.e., high labelling index). Our exploratory study suggests that within node-negative patients, int-2 amplification could be a valuable and independent prognosticator, useful to identify patients at high risk of local-regional recurrence. Int. J. Cancer 74:620–624, 1997.© 1997 Wiley-Liss, Inc.

From July 1, 1979 to June 30, 1983, 136 consecutive patients with category M0 renal cell cancer who had undergone transperitoneal radical nephrectomy at 5 centers entered a prospective randomized trial to compare 500mg. adjuvant medroxyprogesterone 3 times a week for 1 year to no treatment. Sex steroid hormone receptors also were studied in the renal tumor and in the surrounding healthy parenchyma with the dextran-coated charcoal technique. After a median followup period of 3 years (range 13 to 60 months) 30 of 121 evaluable patients (24.8 per cent) experienced relapse, usually in the lung or bones. Relapses occurred in 15 of 58 evaluable patients in the adjuvant treatment group (25.8 per cent) and 15 of 63 evaluable controls (23.8 per cent). The disease recurred more frequently (35.1 per cent) in the 57 patients with no receptors in the tumor than in the 45 with at least 1 receptor (17.8 per cent). These results were independent of adjuvant therapy. After a median 3-year followup, adjuvant medroxyprogesterone acetate was of no therapeutic benefit in patients who had undergone radical nephrectomy and the side effets of the therapy were evident in more than 50 per cent of the patients.

Primary breast cancer tissue and lymph nodes were obtained from 48 patients. Estrogen receptors (ER) and progesterone receptors (PgR) were determined by a dextran-coated charcoal assay. ER were present in 72.9 % of the primary tumors and in 62.4 % of the malignant lymph nodes, whereas PgR were present in 73.0 % and 50.0 % of the cases, respectively. The primary tumor and the corresponding malignant lymph nodes showed an identical ER and PgR status, i.e., both tumor sites were receptor positive or both receptor negative in 89.6 % and 77.1 %, respectively. However, 10.4 % of the patients had ER-positive tumors but ER-negative lymph nodes and 22.9 % had PgR-positive primaries with PgR-negative lymph nodes. No receptor-positive lymph nodes showed a combination with receptor-negative primary tumor. This preliminary data shows that receptor-positive malignant lymph nodes mostly display the same receptor status as the corresponding primary tumor, whereas receptor-negative lymph nodes may have a receptor-positive primary tumor.