Progesterone receptors measurement

Possible Errors in Estrogen and Progesterone Receptor Measurements. 205... 

Most steroid-sensitive cancers express specific cell surface receptors. Prednisone-sensitive lymphomas, estrogen-sensitive breast cancers, and prostatic cancers express specific receptors for corticosteroids, estrogens, and androgens, respectively. It is now possible to assay tumor specimens for steroid receptor content and to identify which individual patients are likely to benefit from hormonal therapy. Measurement of the estrogen receptor (ER) and progesterone receptor (PR) proteins in breast cancer tissue is now standard clinical practice. ER or PR positivity predicts response to hormonal therapy, whereas patients whose tumors are ER-negative generally fail to respond to such treatment. 

Marks, B.D. et al. 2005. Multiparameter analysis of a screen for progesterone receptor ligands comparing fluorescence lifetime and fluorescence polarization measurements. Assay Drug Devel. Technol. 3, 613-622. 

Most hormone-sensitive cancers will express hormone receptors that can be assayed on biopsy specimens. This allows the clinician to predict whether an individual patient is likely to benefit from hormonal therapy. For example, it is now standard to measure estrogen receptor (ER) and progesterone receptor (PR) content in breast cancer tissue. Patients with ER- or PR-positive tumors are more likely to respond to antiestrogen therapy compared with patients who lack these hormone receptors. 

The p53 protein can also been measured by other methods. The LIA method is intended for measurement of the p53 protein in tumor cytosols normally prepared for the routine biochemical measurement of the oestrogen and progesteron receptor status. The LIA method has been demonstrated to be useful and to give prognostic information in a breast cancer material (34). The principal laboratory steps are outlined in Table 3. The LIA measurement of the p53 protein has been compared with immunohistochemical expression and cDNA-based sequencing on more than 200 primary breast cancers (Norberg et al., unpublished data). In brief, the LIA technique seems to have the same principal limitations as the immunohistochemical determination, and the sensitivity and specificity is no better than with immunohistochemical determination. 

Hohnes FA, Fritsche HA, Loewy JW, Geitner AM, Sutton RC, et al. Measurement of estrogen and progesterone receptors in human breast tumors Enzyme immunoassay versus binding assay. J Clin Oncol 1990 8 1025-35. 

There is little doubt that the presence of estrogen and progesterone receptors in breast cancer tissue correlates very well with the response of the patient to endocrine therapy. ERP/progesterone receptor protein (PRP) measurements have... 

In most situations, progesterone receptors are believed to be synthesized as the result of a fully functional ERP complex as an end product of estrogen-stimulated pathways in breast cancer tissue. The measurement of PRP, therefore, has also become important in predicting hormone responsiveness. Additionally, PRP is significant in predicting disease-free survival. 

Menendez-Botet, C. J., Stankievic, R., Schwartz, D., and Schwartz, M. K., Comparison of the quantitative measurement of human estrogen and progesterone receptor in tissue cytosol by the dextran-coated charcoal assay and the Abbott monoclonal enzyme immunoassay. Clin. Chem. (Winston-Salem, N.C.) 34(6), 1225 (1988). 

Figure 16.7 Immunohistochemical staining intensity as a function of the duration of formahn fixation. Immunostaining intensity was measured in triphcate.The coefficients of variation (CVs) were almost aU less than 10% and, for purposes of clarity, are not shown. Staining intensity is measured as mean pixel intensity units on a 1-256 scale. ER(1D5), ER(2-123), PR(636), PR(1294), and Ki-67(MIB-1), DakoCytomation, Carpinteria, CA PR(1A6) and HER2(CB11), Vision Biosystems, NorweU, MA. ER, estrogen receptor PR, progesterone receptor. Reproduced with permission from Reference 15, 2006 American Society for Clinical Pathology.

Formento, J.L. Moll, J.L. Francoual, M. Krebs, B.P. Milano, G. Renee, N. Khater, R. Frenay, M. Namer, M. HPLC micromethod for simultaneous measurement of estradiol, progesterone, androgen and glucocorticoid receptor levels. Application to breast cancer biopsies. Eur.J.Cancer Clin.Oncol., 1987, 23, 1307-1314... 

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