Angiotensin converting enzyme (ACE) (dipeptidyl carboxypeptidase; peptidyldipeptide hydrolase, EC 3.4.15.1) was localized in epithelioid and giant cells within ACE-rich sarcoidosis granulomas, but not control granulomas, by immunofluorescence by using a rabbit anti-human ACE immunoglobulin for localization and fluorescein-labeled goat anti-rabbit immunoglobulin for detection. ACE was frequently not detected in the very central epithelioid cells, perhaps due to a paucity of cellular or molecular stimulatory interaction in this region. The results suggest that marked elevation of ACE in the granulomas and often in the serum in sarcoidosis may be due to intense induction of ACE in most epithelioid and giant cells of the sarcoidosis granulomas.

Breast cancer specimens from 600 women were assayed for estrogen receptors (ER) using an immunocytochemical assay (JCA) employing the monoclonal antiestrophilin antibody H222 Sp 7. Results showed significant correlation with biochemical ER determinations as well as with tumor grade and menopausal status. In 449 cases, results of progesterone receptor assay by ICA using the monoclonal anti-PgR antibody KD 68, also correlated significantly with biochemical PgR measurements. The ERICA/PgRICA positivity was significantly more frequent in postmenopausal white women. Colloid carcinomas were most likely to be ERICA positive and PgRICA positive whereas medullary carcinomas were most often negative. In 47 patients with advanced mammary carcinoma, results of ERICA and PgRICA were more closely related to endocrine response than those of ER and PgR by dextran-coated charcoal assay (DCC). In 339 women with Stage I or Stage I1 breast cancer, ERICA was significantly associated with disease-free survival. Analysis by Cox's proportional hazard model, however, showed PgRICA to be the best predictor of survival and disease-free survival in 197 women at the same stages of disease. These data indicate that ICA is more predictive of prognosis than biochemical ER and PgR. The ease of ICA performance coupled with these results indicate that the method is an acceptable substitute for DCC in analyzing breast cancers for ER/PgR.

It is customary to submit only one portion of a breast cancer to determine if there is amplification or overexpression of the proto-oncogene HER-2/neu. In routine studies of the expression of neu in breast cancer, however, we noted discrepancies in intratumoral positivity. To investigate this phenomenon further, multiple tumor specimens (129 samples) from 41 women with breast cancer were examined. Forty cases were analyzed for neu amplification by slot blot assay and 18 with fluorescent in situ hybridization. Neu overexpression was determined using four different specific antibodies. In more than 50% of cases there were discrepancies in results between the tissue blocks examined. This was evident in both inter- and intra-assay comparisons. It is concluded that intratumoral heterogeneity of neu amplification/overexpression in breast cancer exists to a far greater degree than previously recognized and could be a responsible factor for conflicting published data regarding neu's prognostic significance. Examination of only one tumor sample may not give a true indication of either amplification or overexpression of this oncogene.

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Breast cancer specimens from 114 patients were assayed for the presence of estrogen receptors (ER) utilizing highly specific, monoclonal antiestrophilin antibodies and the peroxidase‐antiperoxidase technique. Results were compared with conventional ER determinations by the dextran‐coated charcoal method (DCC) and were in agreement as to positivity and negativity in 86%. Semiquantifled immunocytologic assay results were in accord with the level of ER as measured by DCC in 66%. The tumors studied included 43 from patients with Stage IV disease where clinical response to hormonal manipulation was known. In the latter group, the immunohistologic method had a sensitivity similar to that of DCC but showed a superior positive predictive value and a significantly better specificity. These results indicate that this new method is a valuable laboratory tool, enabling prediction of hormone responsiveness in advanced mammary carcinoma and capable of performance at the community hospital level.