Immunocytochemical assay for estrogen receptors applied to human prostatic tumors.

An immunocytochemical assay using a monoclonal antibody to estrogen receptor was applied to frozen sections of 43 prostatic tumors. In addition, in 16 tumors the results of the immunocytochemical assay were compared with those obtained using an enzyme immunoassay for estrogen receptor, a tritiated ligand binding assay, and a histochemical procedure using fluorescein-labeled estradiol conjugates. Specimens from 14 patients with benign prostatic hyperplasia and 29 patients with prostatic carcinoma were analyzed in assays in which human breast carcinoma specimens of high, medium, low, or negative estrogen receptor content acted as controls. The intensity of nuclear staining and the percentage of stained cells in the breast sample controls correlated well with estrogen receptor content as determined by both the enzyme immunoassay and the tritiated ligand binding assay. None of the fixed, frozen sections from the 43 prostatic tumors exhibited nuclear staining of either the benign or the malignant epithelial cells or of the stromal components. Negative results were also obtained with the tritiated ligand binding assay. The majority of prostatic samples were negative when using the enzyme immunoassay but four specimens had a mean value of 6.2 fmol/mg protein which is just above the sensitivity of the assay. Using fluorescein-labeled estradiol conjugates both cytoplasmic and nuclear binding was observed in the prostatic samples which did not correlate with the results obtained by the other three procedures.

Growth hormone and prostatic tumours: localization using a monoclonal human growth hormone antibody.

The immunocytochemical detection of endogenous human GH and the binding of exogenously applied human GH in tumour tissue from patients with benign prostatic hyperplasia or prostatic carcinoma is reported. Monoclonal human GH antibody binding was exclusively to the connective tissue in both benign and carcinomatous specimens. Specificity control experiments indicated that the antibody could be absorbed with human GH but not with human prolactin. Preincubating the sections with human GH considerably altered the immunocytochemical staining, reducing the reaction product within the connective tissue in a concentration-dependent manner and revealing a binding site for GH within the cytoplasm of epithelial cells.

The mucin antigens: what are we measuring?

Serum of breast cancer patients contains high molecular weight, mucin-like glycoproteins which are held to be differentiation markers for certain types of normal epithelia, in particular mammary epithelium. These components have primarily been identified using monoclonal antibodies raised against human milk fat globule membranes, tumour extracts or purified mucins. Even so, many of the antibodies produced react with a discrete region of the mucin protein core involving the hydrophilic turn domain APDTRPAP. The present investigation using the anti-urinary mucin antibody, C595, illustrates both the clinical potential of the mucin antigens in breast cancer studies as well as the exquisite specificity of immune recognition of a complex polymorphic glycoprotein at the level of the individual amino acids.

Multicentre tumour marker reference range study.

BACKGROUND: The array of antibodies and assay formats utilised by kit manufacturers contribute to different values being quoted as clinically "normal". Kit-specific reference range limits will maximise the clinical utility of tumour marker assays. MATERIALS AND METHODS: Serum samples (approximately 800) were obtained from volunteers, age 20-70 years, in France, Germany, The Netherlands and Portugal. Each sample was assayed with a number of DPC tumour markers kits. IMMULITE assays were carried out in The Netherlands; Coat-A-Count IRMA, IRMA-Count, Double Antibody and Milenia assays at EURO/DPC Ltd. Analytes included, BR-MA, OM-MA, GI-MA (for the determination of CA 15-3, CA 125 and CA 19-9, respectively), CEA, PSA, PAP and HCG. RESULTS: The median and 95th percentiles for each analyte in each assay format were estimated; where appropriate, data subsets were considered. CONCLUSION: Kit-specific reference range data generated for important tumour marker analytes will help clinicians interprete their assay results.

The immunocytochemical detection of protein hormones in human prostatic tissues.

The immunocytochemical detection of four pituitary protein hormones in tissue from 13 patients with benign prostatic hyperplasia has been described. There have been marked differences in the distribution and intensity of reaction product attributable to the various hormonal antisera. The intracellular presence of endogenous prolactin and FSH in the epithelial cytoplasm has been suggested together with the stromal localization of growth hormone and prolactin. Minimal diffuse staining over most cellular components was observed with the LH antiserum. This technique has provided an invaluable means of studying the potential involvement of pituitary protein hormones in the control of prostatic function and disease.

Epithelial mucin core antigen (EMCA) in assessing therapeutic response in advanced breast cancer--a comparison with CA15.3.

We report a comparative study of CA 15.3 and EMCA (epithelial mucin core antigen) in 77 consecutive women with newly diagnosed UICC assessable metastatic breast cancer, 59 patients received hormones and 18 chemotherapy. Assessments of response were made prior to commencing therapy and repeated 2 monthly. Sites of metastatic disease included bone (34), pulmonary (8), bone and pulmonary (14) and visceral (21). Using a cut-off of 33 U ml-1 changes in EMCA at 2, 4 and 6 months showed a highly significant correlation (P < 0.001) with UICC assessed response at 6 months; selectivity 70%, sensitivity 80%, specificity 91%, positive predictive value 84%; negative predictive value 89% at 2 months. Corresponding values for CA 15.3: selectivity 89%, sensitivity 85%, specificity 91%, PPV 92% and NPV 91%. Four of eight patients unassessable by CA 15.3 were assessable by EMCA; four patients expressed neither marker. EMCA appears to reflect tumour bulk and may be useful in monitoring therapy in patients with advanced breast cancer. With an easier and more robust assay format than CA 15.3, EMCA is potentially a more useful marker.