Assessment of oestrogen receptor content of breast carcinoma by immunohistochemical techniques on fixed and frozen tissue and by biochemical ligand binding assay

Systematic review on hormone receptor testing in breast cancer

Assessment of hormone receptors (estrogen and progesterone) helps to direct therapy for women with breast cancer. Immunohistochemistry is most commonly used to assess hormone receptor status and it is essential that these tests are performed accurately and reliably within and across laboratories. The overall purpose of this guideline is to improve the quality and accuracy of hormone receptor testing and its utility as a prognostic and predictive marker for invasive and in situ breast cancer. Medline, EMBASE, the Cochrane Database of Systematic Reviews, and abstracts from the San Antonio Breast Cancer Symposium were searched. An environmental scan of the internet and of international guideline developers and key organizations was performed. Preanalytic elements such as the collection, fixation, and storage of samples, and analytic elements such as selection of antibodies and scoring methods that seem to offer the best results for immunohistochemical assessment of hormone receptors are presented. Proficiency testing or quality assurance of immunohistochemistry is described.

Cancer care Ontario guideline recommendations for hormone receptor testing in breast cancer

Hormone receptor testing (oestrogen and progesterone) in breast cancer at the time of primary diagnosis is used to guide treatment decisions. Accurate and standardised testing methods are critical to ensure the proper classification of the patient's hormone receptor status. Recommendations were developed to improve the quality and accuracy of hormone receptor testing based on a systematic review conducted jointly by the American Society of Clinical Oncology/College of American Pathologists and Cancer Care Ontario's Program in Evidence-Based Care. Evidence-based recommendations were formulated to set standards for optimising immunohistochemistry in assessing hormone receptor status, as well as assuring quality and proficiency between and within laboratories. A formal external review was conducted to validate the relevance of these recommendations. It is anticipated that widespread adoption of these guidelines will further improve the accuracy of hormone receptor testing in Canada.

Identification of ABCA1 and ABCG1 in milk fat globules and mammary cells--implications for milk cholesterol secretion

The ATP-binding cassette (ABC) transporters ABCA1 and ABCG1 play an important role in cellular cholesterol homeostasis, but their function in mammary gland (MG) tissue remains elusive. A bovine MG model that allows repeated MG sampling in identical animals at different functional stages was used to test whether 1) ABCA1 and ABCG1 protein expression and subcellular localization in mammary epithelial cells (MEC) change during the pregnancy-lactation cycle, and 2) these 2 proteins were present in milk fat globules (MFG). Expression and localization in MEC were investigated in bovine MG tissues at the end of lactation, during the dry period (DP), and early lactation using immunohistochemical and immunofluorescence approaches. The presence of ABCA1 and ABCG1 in MFG isolated from fresh milk was determined by immunofluorescence. The ABCA1 protein expression in MEC, expressed as arbitrary units, was higher during the end of lactation (12.2±0.24) and the DP (12.5±0.22) as compared with during early lactation (10.2±0.65). In contrast, no significant change in ABCG1 expression existed between the stages. Throughout the cycle, ABCA1 and ABCG1 were detected in the apical (41.9±24.8 and 49.0±4.96% of cows, respectively), basal (56.2±28.1 and 54.6±7.78% of cows, respectively), or entire cytoplasm (56.8±13.4 and 61.6±14.4% of cows, respectively) of MEC, or showed combined localization. Unlike ABCG1, ABCA1 was absent at the apical aspect of MEC during early lactation. Immunolabeling experiments revealed the presence of ABCA1 and ABCG1 in MFG membranes. Findings suggest a differential, functional stage-dependent role of ABCA1 and ABCG1 in cholesterol homeostasis of the MG epithelium. The presence of ABCA1 and ABCG1 in MFG membranes suggests that these proteins are involved in cholesterol exchange between MEC and alveolar milk.

Estrogen receptor alpha, estrogen receptor beta, and progesterone receptor as possible prognostic factor in radically resected gallbladder carcinoma

BACKGROUND

Gallbladder carcinoma is a relatively rare malignancy with a poor prognosis. We have often encountered patients in whom the course of their disease differed substantially from what would be predicted based on their clinical staging, which highlights the needs to consider additional predictive factors. Gallbladder carcinoma occurs more frequently in women than men, yet expression of the estrogen receptor (ER) and progesterone (PR) have not been studied. We applied an immunohistochemical stain to examine the expression of ER(alpha), ER(beta), and PR in radically resected gallbladder carcinoma.

MATERIAL AND METHODS

We immunohistochemically investigated 30 specimens of gallbladder adenocarcinoma tissues using ER(alpha), ER(beta), and PR antibodies.

RESULTS

Adenocarcinoma of gallbladder is negative for both ER(alpha) and PR. However, 22 of 30 cases (73.3%) were confirmed positive for ER(beta), which was significantly correlated with tumor differentiation. Five-year survival rates of ER(beta) positive and negative patients were 53.3% and 31.1%, respectively (P = 0.034). In multivariate analysis, only a low proportion score of ER(beta) status was a statistically significant factor (P = 0.033).

CONCLUSIONS

Evaluation of ER(beta) expression in gallbladder carcinoma may be an important factor in identifying a poor prognostic group of gallbladder carcinoma.

Heat-induced antigen retrieval: mechanisms and application to histochemistry

Since the introduction of the fluorescence-labeled antibody method by Coons et al. [Immunological properties of antibody containing a fluorescent group. Proc Soc Exp Biol Med 47, 200-2002], many immunohistochemical methods have been refined to obtain high sensitivity with low background staining at both light and electron microscopic levels. Heat-induced antigen retrieval (HIAR) reported by Shi et al. in the early 1990s has greatly contributed to immunohistochemical analysis for formalin-fixed and paraffin-embedded (FFPE) materials, particularly in the field of pathology. Although antigen retrieval techniques including enzyme digestion, treatment with protein denaturants and heating have been considered tricky and mysterious techniques, the mechanisms of HIAR have been rapidly elucidated. Heating cleaves crosslinks (methylene bridges) and add methylol groups in formaldehyde-fixed proteins and nucleic acids and extends polypeptides to unmask epitopes hidden in the inner portion of antigens or covered by adjacent macromolecules. In buffers having an appropriate pH and ion concentration, epitopes are exposed without entangling the extended polypeptides during cooling process, since polypeptides may strike a balance between hydrophobic attraction force and electrostatic repulsion force. Recent studies have demonstrated that HIAR is applicable for immunohistochemistry with various kinds of specimens, i.e., FFPE materials, frozen sections, plastic-embedded specimens, and physically fixed tissues at both the light- and electron-microscopic levels, and have suggested that the mechanism of HIAR is common to aldehyde-fixed and aldehyde-unfixed materials. Furthermore, heating has been shown to be effective for flow cytometry, nucleic acid histochemistry (fluorescein in situ hybridization (FISH), in situ hybridization (ISH), and terminal deoxynucleotidyl transferase-mediated nick labeling (TUNEL)), and extraction and analysis of macromolecules in both FFPE archive materials and specimens processed by other procedures. In this article, we review mechanism of HIAR and application of heating in both immunohistochemistry and other histochemical reactions.

Comparative analysis of the biochemical and immunohistochemical determination of hormone receptors in invasive breast carcinoma influence of the tumor-stroma ratio

Tumor samples obtained from 106 primary breast cancer patients were examined biochemically (DCCA) and immunohistochemically (IHC) for estrogen (ER) and progesterone receptors (PR) to assess a quantitative relationship between both assays and to study the influence of the tumor-stroma ratio on this quantitative relationship. We used a model of logit transformation of IHC values (% of positive cells) and logarithmic transformation of DCCA values (fmol receptor/mg cytosolic protein). Tumors were subdivided into three categories according to the tumor-stroma ratio (more (t > s), equal amounts (t = s) or less (t < s) tumor than stroma), and the influence of the tumor-stroma ratio was studied using multiple regression analysis. We report a mathematical relationship between the results of the biochemical and immunohistochemical assays for the determination of ER status and PR status in primary breast cancer patients (ER: log DCCA(fmol/mg) = 0.369 logit (IHC(%pos cells)) + 2.328 (r = 0.573; p < 0.0001); PR: log DCCA (fmol/mg) = 0.474 logit (IHC(%pos cells)) + 0, 00 (r = 0.634; p < 0.0001)). In tumors overexpressing ER immunohistochemically (>10% nuclear positivity), median ER-DCCA is significantly higher if the tumor-stroma ratio is greater than 1. As these patients respond to hormonal treatment, depending on the degree of expression of both receptors, this study suggests that the biochemical assay be avoided because this technique is hampered by false-negative or falsely low results due to the loss of morphological information on the tumor-stroma ratio.

Immunohistochemical evaluation of hormone receptor for routine practice of breast cancer: highly sensitive procedures significantly contribute to the correlation with biochemical assays

Immunohistochemical evaluation of hormone receptors for breast cancer has been performed parallel to biochemical assays. Recently, immunohistochemistry has tended to substitute the biochemical method in Japan. To clarify the factors concerned and problems to be resolved, we reviewed our evaluation system for hormone receptors by immunohistochemistry from 1990. A total of 861 breast cancer samples were examined by immunohistochemistry and biochemistry. In 3 main periods, phase 1 (1990-1993), phase 2 (1995-1998), and phase 3 (1999-2001), increasing sensitivity of the immunohistochemical method was provided by commercially available staining systems and shown to range from 83.6% (phase 1) to 92.0% (phase 3). The highly sensitive procedures of the antigen retrieval and peroxidase-conjugated polymer method are main contributing factors. The authors examined how these procedures influenced the distribution of positive cell population; concordance rate, including sensitivity and specificity; cutoff points; and evaluation categories. The correlation between biochemistry and immunohistochemistry was extensively studied in the 1980s and 1990s. In reference to the progress achieved in the United States and United Kingdom to control the current situation in Japan, it should be recognized that recently developed, highly sensitive procedures boost the immunoreactivity, which will affect the basic factors for technical validation.

Determination of estrogen receptor in primary breast cancer using two different monoclonal antibodies, and correlation with its mRNA expression

Estrogen receptor (ER) protein status was investigated in the MCF-7 cell line and 70 invasive ductal carcinomas of the breast. This was achieved by immunohistochemical assay (IHA) using two different monoclonal antibodies (ER-1D5 and AER311), which are able to recognize either the amino or carboxyl terminal. The staining results were assessed in terms of index score, and compared with the ERalpha mRNA expression, which was determined by reverse transcription-polymerase chain reaction for the positions of exons 5 and 7. MCF-7 showed similar immunoreactions with both antibodies, and expressed the wild-type (WT) ER mRNA coexpressing deletions of exons 5 and 7. Although there was a significant difference between the ER-1 D5 and AER311 indices in the tissue samples (20.5 +/- 27.2 and 5.7 +/- 16.4; P < 0.001), in the majority of cases ER mRNA expression patterns were similar to that of MCF-7, and WT ER mRNA was expressed in all cases that yielded PCR products. It was concluded that a number of palpable breast cancers lack the carboxyl terminal of the ER protein, regardless of WT ER mRNA expression. These results suggest that the incidence of WT ER mRNA in such cancers is lower than that in the MCF-7 cell line, or that WT ER is less stable.

Prognostic significance of estrogen receptors in 405 primary breast cancers: a comparison of immunohistochemical and biochemical methods

Over the last few years, estrogen receptor determination by means of immunohistochemistry has been extensively used. The aim of this study was to compare this technique with estrogen receptor determination by means of dextran-coated charcoal, and to evaluate whether one of the two methods is more predictive of prognosis. Estrogen receptors were determined by means of both the dextran-coated charcoal method and immunohistochemistry in 405 patients with primary breast cancer; age, pathological tumor size, nodal status, and progesteron receptors by dextran-coated charcoal method were also recorded. The disease-free and overall survival probabilities were estimated using the product-limit method; Cox's proportional hazard model was used to evaluate the prognostic role of estrogen receptors as determined by the two methods. There appears to be a close association between estrogen receptor determination by the two methods (81.5% of concordant results) and their prognostic role was similar, even when the patients were divided into different groups (on the basis of their estrogen receptor status) and adjustments for the effect of other prognostic variables were taken into account. Our study shows that the two methods can be used indifferently to evaluate estrogen receptor status as a prognostic factor in breast cancer patients.

Immunohistochemical detection of oestrogen receptors in ductal carcinoma in situ of the breast

The expression of oestrogen receptor (ER) protein in invasive carcinoma of the breast and its clinical significance has been extensively evaluated. Little information is available regarding ER expression in ductal carcinoma in situ (DCIS). In this study, 46 formalin-fixed, paraffin-embedded tissue specimens of mammographically detected DCIS were evaluated immunohistochemically for the presence of ER using specific monoclonal antibodies against ER (ER-ICA Abbott Lab). The associations between ER expression and histological type, degree of differentiation and patient menopausal status were evaluated. Positive ER staining was present in 72% of cases. Non-comedo types of DCIS were more frequently ER-positive than comedocarcinoma. ER-positive tumours were inversely correlated with the presence of nuclear pleomorphism. The incidence of ER in pre-menopausal and post-menopausal women was similar. In conclusion, ER expression is present in a considerable percentage of DCIS, and ER-positivity is associated with the degree of differentiation and non-comedo carcinoma variants.

Estrogen receptors in 699 primary breast cancers: a comparison of immunohistochemical and biochemical methods

BACKGROUND

Over the last few years, estrogen receptor (ER) determination by immunohistochemistry (ER-ICA) has been extensively used, but it still remains to be established whether this method can replace the standard biochemical technique using dextran-coated charcoal (ERDCC).

PATIENTS AND METHODS

ER were determined by both the dextran-coated charcoal (DCC) method and immunohistochemistry (ICA) in 699 patients with primary breast cancer; other parameters (age, pathological T-pT- and nodal status -pN-, progesterone receptors by DCC, proliferative index by ICA) were also recorded. The 'best' cut-off for ERICA was evaluated by means of Receiver Operating Characteristics (R.O.C.) analysis; logistic regression analysis was used to find adequate 'weights' for stain intensity.

RESULTS AND CONCLUSIONS

A significant correlation was found between the two methods (p < 0.001). R.O.C. analysis revealed that the 'best' cut-off for the ERICA score was 45% (sensitivity 0.810, specificity 0.804). Logistic regression analysis showed that an ERICA score which also considers staining intensity does not add any useful information concerning ER content in breast cancers.

A new immunohistochemical antibody for the assessment of estrogen receptor status on routine formalin-fixed tissue samples

We describe a method for the immunocytochemical assessment of estrogen receptor (ER) status on routinely processed, formalin-fixed tissue using a recently developed commercially available monoclonal antibody (Dako 1D5) with a microwave antigen retrieval technique. A series of 90 cases of human breast carcinoma was analyzed and the staining was assessed using a semiquantitative microscopic scoring method and by assessment of the percentage of nuclei showing positive staining. The results were compared with assessment using another commercially available antibody (Abbott H222) and with clinical response to tamoxifen therapy. Direct comparison of the paired sets of H scores and the percentage of positively stained nuclei using the two different techniques showed a significant correlation. By assigning an arbitrary cut-off for positivity of H score = 50, assessment of ER status using DAKO 1D5 antibody was found to correlate with response to tamoxifen therapy with a sensitivity of 90% and a specificity of 51%, similar to values in previous studies using other methods. We conclude that assessment of ER status using this new antibody and technique gives accurate results on routinely processed, formalin-fixed tissue and may be used as an alternative to other methods.

Wet autoclave pretreatment for immunohistochemical demonstration of oestrogen receptors in routinely processed breast carcinoma tissue

The immunohistochemical demonstration of oestrogen receptor (OR) was performed on 32 randomly selected and routinely processed breast carcinomas after wet autoclave pretreatment of sections. The autoclave method was compared to the OR status found on frozen sections as well as to alternative pretreatment methods such as enzymatic predigestion and microwave irradiation. Using four different monoclonal antibody clones (H222, LH1, CC4-5, 1D5.26), the OR status was evaluated for each of the various pretreatment methods applied. All cases with a high OR content on frozen sections (n = 11) also showed a high OR status on wet autoclave-pretreated paraffin tissues using antibody clones 1D5.26 and CC4-5; in cases with low OR content on frozen sections, no false-negative cases were recorded using only the antibody 1D5.26 neither after wet autoclave nor microwave pretreatment. In addition, with this antibody, OR was detectable after autoclave pretreatment in two cases which were considered to be OR-negative even on frozen sections. When the primary antibody was omitted, no false-positive cases were observed after wet autoclave pretreatment. Thus, in our hands, wet autoclave pretreatment, in combination with the antibody 1D5.26, offers a highly sensitive method for the immunohistochemical demonstration of OR in routinely formalin-fixed, paraffin-embedded sections of breast carcinomas.

The estrogen receptor expression in the male rabbit urethra and prostate following castration

The influence of castration on estrogen receptor (ER) expression in the male rabbit prostate and urethra, was investigated immunohistochemically and biochemically in 18 mature male, rabbits 14 days after bilateral orchiectomy, and in 15 controls. Immunohistochemical scores of ER were increased significantly in the prostatic stroma and the urethral submucosa (p < 0.05 Mann-Whitney), while the increase in the urothelium was not significant. Biochemically, the ER content was 87.4 +/- 42.6 f mol/mg protein in the normal prostate, and 190.0 +/- 28.0 f mol/mg protein following castration. The corresponding values for the posterior urethra were 228.3 +/- 43.2 f mol/mg protein and 354.9 +/- 60.1 f mol/mg protein. In both cases the increase was not significant. We conclude, that ERs in the prostate and the urethra of the male rabbit can be modified by hormonal manipulation. ERs may therefore be functionally active and not rudimentary.

Methodology of immunohistological detection of oestrogen receptor in human breast carcinoma in formalin-fixed, paraffin-embedded tissue: a comparison with frozen section methodology

We describe a method of immunohistochemically assessing estrogen receptor status on routinely processed formalin-fixed tissue, using a commercially available monoclonal antibody (Abbott H222), with pronase predigestion of tissue sections and overnight antibody incubation. The staining was assessed using the H score system. A series of 94 cases of breast cancer were analysed and the results were compared with assessment by oestrogen receptor immunocytochemical assay performed on frozen section. Direct comparison of the paired sets of H scores obtained with frozen tissue and formalin-fixed tissue showed a highly significant correlation of 0.8 (P < 0.001) between the two methods of oestrogen receptor assessment. Chi-squared analysis using H score cut off points of 50 and 100 also showed a similar significant association (P < 0.001). We conclude that this oestrogen receptor method, applicable to formalin-fixed, paraffin-embedded tissue, gives accurate results on routinely fixed tissue and could be used as an alternative to other methods.

Oestrogen receptor expression in ductal carcinoma in situ of the breast: relationship to flow cytometric analysis of DNA and expression of the c-erbB-2 oncoprotein

The expression of oestrogen receptor protein (ER) was examined in 151 cases of symptomatic or screening detected pure ductal carcinoma in situ (DCIS) of the breast by immunocytochemical assay (ERICA), in formalin-fixed paraffin-embedded tissue, with the monoclonal antibody H 222 (Abbott). Forty-eight tumours (31.8%) of cases were ER positive. Twenty-seven (17.9%) of cases showed high level ER expression and 21 (13.9%) of cases showed low level ER immunoreactivity. Significant associations of positive tumour ER immunoreactivity and non-comedo architecture chi 2 = 6.76; (d.f. = 1): P < 0.001, small cell size chi 2 = 4.49; (d.f. = 1): P = 0.034, higher S-phase fraction chi 2 = 4.71; (d.f. = 1): P = 0.03 and lack of c-erbB-2 protein overexpression chi 2 = 7.96; (d.f. = 1): P < 0.01 were identified. No significant associations of ER expression and patient age, histological grade of necrosis in DCIS, or DNA ploidy were found. ER expression is detectable in less than one third of symptomatic and screening detected cases of DCIS, implying that endocrine therapy of DCIS may be a more appropriate form of management for morphological subtypes of DCIS which show higher rates of oestrogen receptor expression, particularly those of non-comedo and small cell type.

Influence of menstrual cycle, parity and oral contraceptive use on steroid hormone receptors in normal breast

Steroid receptor was assessed immunohistochemically in 158 samples of normal breast for variation through the menstrual cycle. Patterns and intensity of reaction were used in a semi-quantitative scoring system to examine the influence of cycle phase, cycle type, parity and age. The changes in oestrogen receptor for natural cycle and oral contraceptive (OC) cycles indicated down-regulation by progestins. Progesterone receptor did not vary significantly in natural cycles, but increased steadily through OC cycles. This study provides strong evidence that both oestrogen and progesterone influence breast epithelium, but dissimilarities from the endometrium are apparent. The interval since pregnancy had a significant negative effect on frequency and score of oestrogen receptor and score of progesterone receptor. Multivariate analysis established the phase of cycle and OC use as independent significant influences on oestrogen receptor. The interval since pregnancy was an independent significant factor for both oestrogen and progesterone receptor presence.

Comparative evaluation of fresh, fixed, and cryopreserved solid tumor cells for reliable flow cytometry of DNA and tumor associated antigen

Five different protocols for the short-term preservation of cells used for multiparameter flow cytometric assay of tumour associated antigens (TAA) and DNA were assessed in cell suspensions prepared by mechanical disaggregation of 15 gynecological tumors. The protocols at 4 degrees C were 1) storage in buffer, 2) storage in 50% methanol, and 3) storage in buffer after formalin fixation. Tissues were also cryopreserved as cell suspensions and tissue blocks. When the TAA expression and DNA histograms of the preserved cells were compared with those in fresh cell suspensions, cryopreservation was found to be the best method: TAA expression was well preserved and there was a good correlation between TAA expression and the quality of the DNA histograms, respectively, in fresh and cryopreserved cells (RS: 0.82-0.91, P less than 0.001 for all TAAs). The cell suspensions preserved at 4 degrees C all showed a significant increase in background fluorescence (P less than 0.05) and a reduction in the TAA specific fluorescence (P less than 0.011). Methanol fixation was better than buffered formalin for the proteins studied, though both gave significantly worse results than cryopreservation. The quality of these cell suspensions and the correlation with TAA measurements in fresh cell suspensions deteriorated progressively with time, particularly if they were stored more than a week.

Oestrogen receptor assay of breast cancer by immunocytochemistry of fine needle aspirates

Sixty-five patients with operable breast cancer were studied to assess the reliability of immunocytochemical analysis of oestrogen receptor (ER-ICA) in specimens obtained by percutaneous fine needle aspiration. Results obtained with the commercially available ER-ICA kit were compared with those obtained by the routine biochemical radioligand assay of oestrogen receptor (ER) on excised tumour specimens. Fifty-two of 65 percutaneous aspirates were evaluable. Of these, thirty-five (67%) were ER positive by the radioligand method. ER-ICA was found to be a reliable method for oestrogen receptor assay, with a high concordance (90.4%) between it and the radioligand essay. The ER-ICA assay had a sensitivity of 89%, specificity of 94%, positive predictive value of 97% and negative predictive value of 80%. ER-ICA assay performed on material obtained by fine-needle aspiration is a reliable method of ER assay. It can replace formal biopsy for patients with inoperable primary tumours or accessible metastases.