Immunohistologic localization of estrogen receptors in breast cancer with monoclonal antibodies. Correlation with biochemistry and clinical endocrine response

Estrogen, Progesterone Receptors and Proliferating Activity Evaluated by Immunocytochemistry in Breast Cancer

The correlation of the most important prognostic indicators was evaluated in 75 breast cancer cases. Estrogen-progesterone receptors and proliferating activity were analyzed by immunocytochemical methods (ER-ICA, PR-ICA, Ki-67). Both steroid receptors were inversely correlated with the proliferating activity (ER-ICA vs Ki-67, p < 0.003; PR-ICA vs. Ki-67, p < 0.0001). No correlation was found between steroid receptors or cell kinetics and tumor size or lymph node status. These findings confirm the relevance of biochemical and kinetic parameters as independent markers in breast cancer and suggest a routine use of the simple immunocytochemical methods in assessing the biological behavior of tumors.

Functional and molecular characterisation of EO771.LMB tumours, a new C57BL/6-mouse-derived model of spontaneously metastatic mammary cancer

The translation of basic research into improved therapies for breast cancer patients requires relevant preclinical models that incorporate spontaneous metastasis. We have completed a functional and molecular characterisation of a new isogenic C57BL/6 mouse model of breast cancer metastasis, comparing and contrasting it with the established BALB/c 4T1 model. Metastatic EO771.LMB tumours were derived from poorly metastatic parental EO771 mammary tumours. Functional differences were evaluated using both in vitro assays and spontaneous metastasis assays in mice. Results were compared to non-metastatic 67NR and metastatic 4T1.2 tumours of the 4T1 model. Protein and transcript levels of markers of human breast cancer molecular subtypes were measured in the four tumour lines, as well as p53 (Tp53) tumour-suppressor gene status and responses to tamoxifen in vivo and in vitro. Array-based expression profiling of whole tumours identified genes and pathways that were deregulated in metastatic tumours. EO771.LMB cells metastasised spontaneously to lung in C57BL/6 mice and displayed increased invasive capacity compared with parental EO771. By immunohistochemical assessment, EO771 and EO771.LMB were basal-like, as was the 4T1.2 tumour, whereas 67NR had a luminal phenotype. Primary tumours from all lines were negative for progesterone receptor, Erb-b2/Neu and cytokeratin 5/6, but positive for epidermal growth factor receptor (EGFR). Only 67NR displayed nuclear estrogen receptor alpha (ERα) positivity. EO771 and EO771.LMB expressed mutant p53, whereas 67NR and 4T1.2 were p53-null. Integrated molecular analysis of both the EO771/EO771.LMB and 67NR/4T1.2 pairs indicated that upregulation of matrix metalloproteinase-3 (MMP-3), parathyroid hormone-like hormone (Pthlh) and S100 calcium binding protein A8 (S100a8) and downregulation of the thrombospondin receptor (Cd36) might be causally involved in metastatic dissemination of breast cancer.

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.

A pathologist's perspective on emerging genomic tests for breast cancer

Emerging molecular tests for breast cancer indicate how future progress in diagnostic pathology might guide patient care. However, the challenge will be to bring the best results from this exciting research into clinical use as accurate and reliable standardized tests that integrate into the diagnostic work-up.

Cytometrical image analysis for immunohistochemical hormone receptor status in breast carcinomas

A cytometrical image analyzing method for nuclear protein was established using WinROOF, a commercially available, inexpensive software, to determine the status of both estrogen and progesterone receptors. Immunohistochemical evaluation of estrogen receptors (ER) and progesterone receptors (PR) was performed with the anti-ER (clone 1D5) and the anti-PR (clone PgR636), respectively, combined with dextran polymer reagent EnVision+, all of which are approved in vitro diagnostics in Japan. The immunostained results were captured as digital images in Windows, and then analyzed in WinROOF with macroinstructions for analyzing each captured area either immunolabeled with chromogen or counterstained with hematoxylin. This image analysis method graded the immunostained nuclei of carcinoma cells based on staining intensities, and calculated the labeling index (LI) for both ER and PR. Furthermore, the LI correlated highly with the results from a histology score (HSCORE) when 20 breast carcinomas were quantified. Regarding ER, when 20% in the LI was considered as the cut-off point for positive, the positivity of ER in computer-assisted analysis was 75% (15 of 20 cases), and was completely concordant with that of HSCORE-based analysis. These results indicate that the cytometrical image analysis-based quantification could be appropriately applied to the objective determination of the immunohistochemical status of both ER and PR.

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.

Issues and barriers to development of clinically useful tumor markers: a development pathway proposal

There are few tumor markers that are clinically useful in predicting therapeutic responses or patient outcomes despite nearly 20 years of advances in molecular biology. We discuss a variety of issues and barriers that have affected movement of clinical tests from research into clinical practice. Studies of new markers frequently lack clear hypotheses and are generally underpowered to reach statistically valid conclusions. Relevant clinical endpoints may not be possible to evaluate, often leading to suboptimal study designs. Major stumbling blocks exist because studies are rarely comparable. This makes it difficult to determine why results vary from study to study. It also prevents pooling of small datasets for analysis. We propose a tumor marker development pathway that we think will be more efficient and effective. The pathway depends on developing statistically valid study designs, focusing on assay refinement and standardization early in the process, including assay details in publications, and providing data in a format that allows comparison with other studies. The process described should be applicable to development of new technologies that include analysis and interpretation of large, complex datasets. The proposed marker development pathway will require thoughtful refinement and expansion, but it should begin a productive dialog.

Steroid Hormone Receptor Immunohistochemistry in Breast Cancer: Past, Present, and Future

This article reviews the development of steroid hormone receptor detection using the biochemical approach and the disadvantages inherent in these systems. The early history of methods for the in situ detection of receptors is related, culminating in the development of histologic immunoassays using monoclonal antibodies. Correlation of the latter with disease-free and overall survival and with clinical endocrine response are presented together with preliminary findings utilizing a new generation of antireceptor antibodies. Current problems with test scoring and interpretation are detailed with a section devoted to image analysis for assay quantification. Emphasis is placed on the fact that because so many different antibodies and tissue substrates have been employed in the past, these histologic receptor immunoassays cannot yet be considered to be fully validated. It is stressed that different laboratories must employ the same antibodies, substrates, detection systems and methods of scoring, and then correlate findings with measurable clinical end points. Only then can the assays be included in the brief list of approved breast cancer prognostic and predictive markers to eventually replace the routine biochemical methods of steroid receptor detection.

Computer-assisted immunocytochemical determination of breast cancer steroid receptors. Frozen sections vs paraffin sections

Previously we have demonstrated that determination of oestrogen (ER) and progesterone (PR) receptors by immunocytochemical assay (ICA) on frozen sections (FS) and cytological smears with image analysis is effective for evaluating steroid receptors. The aim of this study was to determine concordance between ER and PR assessed by ICA on FS and paraffin sections (PS) both evaluated by image analysis. There were 115 breast carcinomas selected. For all cases, ER and PR determination was performed on FS and PS. Computer-assisted image analysis was performed using CAS 200. Results were expressed as percent positive area of neoplastic nuclei compared with total nuclear area of the examined neoplastic cells. Good correlation was demonstrated for both ER (r=0.759; concordance=83.4%) and PR (r=0.800; concordance=87.8%). The unexpected relatively low concordance for ER led to further investigations. We divided the 115 cases in two groups. The first group included specimens from our hospital; the second group specimens from suburban hospitals. In the first group there was better correlation for both ER (r=0.897) and PR (r=0.915) with a concordance of 91.5% and 93.6%, respectively. In the second group, correlation was worse for both ER (r=0.724) and PR (r=0.708), with a concordance of 77.9% and 83.9% respectively. From analysis of discordant cases we conclude that reduction in correlation and concordance with increased false negative cases in group 2 are probably due to delayed fixation. Our data suggest that ICA with automated image analysis is efficient in evaluating ER and PR on paraffin section only when the tumour samples are correctly fixed.

Absence of type I estrogen receptors in choroidal melanoma: analysis of Collaborative Ocular Melanoma Study (COMS) eyes

PURPOSE

To evaluate choroidal melanomas in enucleated eyes for the presence of type I estrogen receptors.

METHODS

Fourteen consecutive eyes with large choroidal melanomas (defined as >16-mm basal diameter and >8 mm thickness) from 14 patients (eight women and six men with a mean age of 57 years; range, 25--74 years) enucleated in accordance with the Collaborative Ocular Melanoma Study (COMS) protocol were investigated. Immunohistochemical techniques were employed to label the choroidal melanomas for the presence of type I estrogen receptors. Each specimen was then evaluated in a masked fashion by an experienced ophthalmic pathologist for positive nuclear staining.

RESULTS

No tumors showed immunohistochemical evidence of a type I estrogen receptor.

CONCLUSION

Type I estrogen receptors are not present in choroidal melanoma. Estrogens are not likely to influence choroidal melanoma growth through traditional receptors.

Estrogen-receptor-directed neoadjuvant therapy for breast cancer: results of a randomised trial using formestane and methotrexate, mitozantrone and mitomycin C (MMM) chemotherapy

BACKGROUND

We wanted to determine whether neoadjuvant systemic chemoendocrine therapy guided by the estrogen receptor (ER) status of the primary breast cancer, followed by conventional surgery and/or radiotherapy, reduces local and distant recurrence and improves survival compared with adjuvant treatment given conventionally postoperatively.

PATIENTS AND METHODS

Two hundred ten patients with primary breast cancer (T1-T4, N0, N1-2) were randomised to receive treatment with neoadjuvant chemoendocrine therapy or conventional post-operative chemoendocrine therapy. Systemic therapy was based on the estrogen receptor (ER) status of the primary tumour obtained by trucut core biopsy. ER-negative patients received MMM chemotherapy (methotrexate (30 mg/m2), mitozantrone (7 mg/m2) and mitomycin (7 mg/m2) three-weekly for three months and ER-positive patients who were premenopausal received goserelin (3.75 mg monthly), and post menopausal women formestane (250 mg every two weeks) over three months.

RESULTS

With a minimum of five years follow-up, there is no evidence of any survival benefit from the pretreatment neoadjuvant therapy regimen, with five year overall survival being 79% +/- 4.7% (neoadjuvant) and 87% +/- 3.4% (adjuvant). Similarly, there was no apparent benefit in terms of disease-free survival. There was, however, a significant reduction in the incidence of distant metastases in responders (4 of 51; 8%) compared with non-responders (17 of 49; 35%) (P < 0.01). There was a reduction in the need for surgery in responding patients with T1 and T2 tumours, since 10 of 74 (14%) had no detectable residual tumour, without any apparent increase in the risk of local or distant recurrence.

CONCLUSION

In this study neoadjuvant treatment with endocrine or chemotherapy provided no obvious survival benefit to women with breast cancer. However, it does allow avoidance of surgery in some cases. Also, the patients whose tumours respond to neoadjuvant systemic therapy have a lower incidence of distant metastases after five year follow-up compared to those whose tumours fail to respond.

Estrogen receptor beta expression in invasive breast cancer

The aim of this work was to determine the extent of estrogen receptor beta (ER-beta) expression in invasive breast cancer (BrCA) and whether ER-beta expression is correlated with response to adjuvant hormonal therapy with tamoxifen (AHTT). Immunohistochemical staining (IHC) for estrogen receptor alpha (ER-alpha) and ER-beta was performed on sections of formalin-fixed and paraffin-embedded tissue from 47 unselected invasive breast carcinomas (BrCA). IHC for ER-beta was also performed on sections of BrCA from 118 women who were treated with mastectomy and AHTT. Survival analysis was performed using the Kaplan-Meier method and the log-rank test. Of the 47 unselected BrCA, 17 (36%) were negative for ER-alpha and of these, 8 (47% of ER-alpha negative cases and 17% of all 47 patients) were ER-beta positive. Five of the 8 ER-alpha negative and ER-beta positive cases were positive for ER biochemically. There was no correlation between ER-beta positivity and overall survival in the unselected group. By contrast, in the group of women treated with AHTT, expression of ER-beta in more than 10% of cancer cells was associated with better survival (P = .0077), even in women with node-negative BrCA (P = .0069). In conclusion, our results show that a significant number of women with BrCA are positive for ER-beta only, and may be determined to be ER-negative when currently available IHC is used. ER-beta status is a significant predictor of response to AHTT in women with BrCA. Larger studies with multivariate analysis are needed to confirm these findings.

Estrogen receptor status by immunohistochemistry is superior to the ligand-binding assay for predicting response to adjuvant endocrine therapy in breast cancer

PURPOSE

Immunohistochemistry (IHC) is a newer technique for assessing the estrogen receptor (ER) status of breast cancers, with the potential to overcome many of the shortcomings associated with the traditional ligand-binding assay (LBA). The purpose of this study was to evaluate the ability of ER status determination by IHC, compared with LBA, to predict clinical outcome-especially response to adjuvant endocrine therapy-in a large number of patients with long-term clinical follow-up.

PATIENTS AND METHODS

ER status was evaluated in 1,982 primary breast cancers by IHC on formalin-fixed paraffin-embedded tissue sections, using antibody 6F11 and standard methodology. Slides were scored on a scale representing the estimated proportion and intensity of positive-staining tumor cells (range, 0 to 8). Results were compared with ER values obtained by the LBA in the same tumors and to clinical outcome.

RESULTS

An IHC score of greater than 2 (corresponding to as few as 1% to 10% weakly positive cells) was used to define ER positivity on the basis of a univariate cut-point analysis of all possible scores and disease-free survival (DFS) in patients receiving any adjuvant endocrine therapy. Using this definition, 71% of all tumors were determined to be ER-positive by IHC, and the level of agreement with the LBA was 86%. In multivariate analyses of patients receiving adjuvant endocrine therapy alone, ER status determined by IHC was better than that determined by the LBA at predicting improved DFS (hazard ratios/P = 0.474/.0008 and 0.707/.3214, respectively) and equivalent at predicting overall survival (0.379/.0001 and 0.381/.0003, respectively).

CONCLUSION

IHC is superior to the LBA for assessing ER status in primary breast cancer because it is easier, safer, and less expensive, and has an equivalent or better ability to predict response to adjuvant endocrine therapy.

Immunoperoxidase staining for estrogen and progesterone receptors in archival formalin fixed, paraffin embedded breast carcinomas after microwave antigen retrieval

Immunoperoxidase staining was performed for estrogen and progesterone receptors in 93 cases of primary breast carcinoma. Breast tumor samples were fixed in formalin and embedded in paraffin. Antigen retrieval was performed by microwave heating in citrate buffer, pH 6.0, using precisely defined and reproducible conditions. The cases studied included material from the current year and from paraffin blocks retrieved from archival storage dating back to 1981. In all cases, estrogen and progesterone receptor values determined by biochemical assay were available for comparison with the immunohistochemical results. We found 94% agreement of results between the two methods.

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.

Hormonal receptors in mammary carcinoma: comparison between quantitative and qualitative methods

Alternatives to the traditional hormone receptor dosages for prognostic evaluation and clinical approach to breast cancer have been proposed for immunohistochemical determinations. For correlation purposes, such procedures were compared in 37 patients presenting 5 to 15 years of survival. Considering 30 fm/mg as the positivity index, the disagreement between both methods reached 35.1% with estrogen and 48.5% with progesterone receptors. When the positiveness level was changed to 20 fm/mg, the discrepancies were reduced to 32% with ER and increased to 57% with PgR. This study leads us to not recommend the immunohistochemical method applied to paraffin sections as an alternative procedure to the dextran-charcoal dosage for prognosis and therapeutic management of mammary carcinoma.

Tumor proliferative activity and response to first-line chemotherapy in advanced breast carcinoma

The relationship between tumor proliferative activity and response to first-line chemotherapy and survival was investigated in 76 advanced breast cancer patients. Proliferative activity was determined by means of Ki-67 immunohistologic staining on primary tumors (55 patients) or at the relapse site (21 patients), and was classified as low ( < or = 25% of stained cells) or high ( > 25% of stained cells). The usual WHO response criteria were used. The median duration of follow-up was 18 months (range 3-58). Forty-seven patients (62%) had tumors with low, and 29 (38%) had tumors with a high rate of proliferative activity. The two groups were well balanced in terms of important variables such as disease-free survival, performance status, age, menopausal status, and the type of first-line chemotherapy (anthracycline-based regimens versus cyclophosphamide-methotrexate-5-fluorouracil). The estrogen receptor (ER) content, measured by means of immunohistochemical assay, was markedly different in the two groups, with 27/47 tumors with low proliferative activity (57%) and 6/29 with high-proliferative activity (21%) being ER positive ( > or = 45% of stained cells) (p = 0.003). Moreover, a significant difference in the metastatic pattern was also evident, with a higher incidence of bone and a lower incidence of soft tissue metastases in the group of patients with tumors with low proliferative activity (p = 0.004). Overall, 10/47 responses (21%: PR = 7, and CR = 3) were observed in the group with a low rate of proliferative activity, versus 14/29 (48%: PR = 9, and CR = 5) in the group with highly proliferative tumors, the difference being statistically significant (p = 0.03). When a multivariate analysis was performed, the only factor that retained independent prognostic significance was the predominant site of disease, particularly soft tissues (p = 0.003). Despite the difference in response rate, when survival analysis was performed according to the Kaplan-Meier method, no significant difference was observed in the two groups, but when the analysis was limited to responsive patients, the median survival observed in those with a low and those with a high rate of proliferation was 35 and 19 months respectively (p = 0.02). The same results were obtained when multivariate survival analysis was carried out using Cox's regression model. These data suggest that there is a link between tumor proliferative activity and response to chemotherapy in advanced breast cancer, and may indicate the need to use more intensive treatments in selected patients with highly proliferative tumors.

pS2 protein: a marker improving prediction of response to neoadjuvant tamoxifen in post-menopausal breast cancer patients

Tamoxifen as sole initial therapy is gaining importance in the management of post-menopausal breast cancer patients. Age oestrogen (ER) and progesterone (PR) receptor status are accurately considered to select patients for hormonal treatment. However, additional markers are needed. By immunohistochemistry (IHC), we studied tumour expression of ER, PR, pS2, c-erbB-2 and glutathione S-transferase pi (GST pi) on initial core biopsies of 208 post-menopausal patients with a non-metastatic invasive ductal carcinoma, treated by neoadjuvant tamoxifen therapy. A good response to tamoxifen was defined as tumoral regression > or = 50% (110 patients). Relationship between response and age, tumour size, T, N, histological grade, ER and PR contents evaluated by radioimmunoassay, ER, PR, pS2, c-erbB-2 and GST pi expression evaluated by IHC were studied. Univariate and multivariate analysis showed that tumoral regression was linked only to pS2 (P = 0.004) and ER (P = 0.018) IHC expression. According to the immunohistochemical profile, three groups could be defined: pS2- and ER-positive tumours, pS2- or ER-positive tumours and pS2- and ER-negative tumours with response rates of 60%, 45% and 8% respectively. Although prospective studies are needed to confirm these results, we conclude that pS2 and ER immunohistochemical status are useful tools for predicting tumour regression with neoadjuvant tamoxifen in post-menopausal breast carcinoma patients.

Estrogen and progesterone receptor status determined by the Ventana ES 320 automated immunohistochemical stainer and the CAS 200 image analyzer in 236 early-stage breast carcinomas: prognostic significance

The quantitation of estrogen and progesterone receptors (ER and PgR) has become the standard of care in the evaluation of patients with primary breast carcinoma. It has been demonstrated that ER and PgR detected by immunohistochemical methods in formalin-fixed paraffin-embedded tissue can be quantified by computerized image analysis. In this study, ER and PgR levels were determined by using an automated immunochemistry stainer (Ventana ES 320) and an image analyzer (CAS 200) in a series of 236 patients with stage I/II carcinoma of the breast. The degree of correlation of the ER and PgR levels determined by the dextran-coated charcoal method (DCC) with image analysis quantitation was high (r=0.75). The agreement between both methods was 77% for ER and 73% for PgR. Hormone receptor levels were correlated with prognosis as determined by overall survival. An ER level of 30 fmol/mg as determined by image analysis was established to stratify the patient population most effectively into favorable and unfavorable prognostic groups (P=0.003). An ER level of 20 fmol/mg for prognostic stratification reached statistical significance (P=0.03). The DCC method was not able to stratify the patients into prognostic groups at the traditionally accepted cutpoint of 10 fmol/mg (P=0.52). We conclude that when used in combination, automated immunohistochemistry and quantitative image analysis offer a favorable alternative to the DCC method in assessment of ER and PgR status in human mammary carcinoma. In addition, quantitative immunocytochemistry techniques may prove superior to the DCC method in specimens in which there is limited tumor volume (including fine-needle aspirates), stroma-rich tumors, and early-stage lesions including intraductal carcinoma.

Prognostic factors in breast cancer: use of cytologic preparations

There is increasing evidence that certain morphological features and biological markers found in breast tumors may provide prognostic information by predicting the risk of recurrence and metastasis in early breast cancer. This information may also be important in choosing therapeutic options in patients with advanced disease. Prognostic testing is commonly performed on surgically excised lesions. However, there are clinical conditions in which a surgical specimen may not be suitable or available for such analysis. In these circumstances, fine-needle aspiration biopsy and imprint preparation provide an attractive sample for prognostic testings. This review summarizes the current approach to the use of cytologic preparation for assessment of established and newly recognized prognostic factors.

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.

Relationship between low estrogen receptor values and other prognostic factors in primary breast tumors

BACKGROUND

The current study compared the immunocytochemical expression of estrogen (ER) and progesterone (PgR) receptors by malignant breast cells to the hormone receptor concentrations reported from radioligand assays. These values were examined in relation to DNA ploidy and the fraction of cells in S phase.

METHODS

ER and PgR concentrations, DNA ploidy, and S-phase fractions were measured by standard techniques with 124 samples of invasive ductal carcinoma. Suspensions of tumor cells were examined by immunocytochemical assay (ICA) for the percentages of ER and PgR positive cells.

RESULTS

Twenty-six of the 38 tumors from patients 50 years of age or younger were classified as high S-phase fraction, and 28 tumors had aneuploid levels of DNA. The 20 ER positive tumors each contained less than 100 fmol/mg. Thirty-nine of the 86 tumors from patients older than 50 years were classified as high S phase, and 41 were aneuploid. Sixty-five samples were considered ER positive by radioligand assay. ICA showed that tumors in either age group with less than 40 fmol/mg did not contain ER positive cells. The proportion of samples with PgR levels between 10 and 100 fmol/mg was small, and fewer PgR positive tumors were categorized as negative when examined by ICA for receptor containing cells. The reclassification of the hormone receptor status of a tumor based on ICA appeared to be independent of S-phase and ploidy values.

CONCLUSIONS

Tumors that are classified as ER or PgR positive based on accepted cutoff values for radioligand assays may actually be receptor negative because the tumors do not appear to contain receptor positive cells.

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.

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.

Immunohistochemical detection of female sex hormone receptors in meningiomas: correlation with clinical and histological features

Sixty-one meningiomas from 60 patients were screened for estrogen receptors and progesterone receptors (PgR) with monoclonal antibodies in an immunohistochemical assay. In addition, 43 of the cases were evaluated for tumor size and peritumoral edema, as seen on computed tomographic scans and magnetic resonance images. Sixty-one percent of the tumors contained significant amounts of PgR, whereas no estrogen receptor-positive tumor was observed. Thirteen percent of all tumors were classified as nonbenign variants (atypical and anaplastic meningiomas) and were more frequently found in male patients (P < 0.05). Nonbenign tumors more frequently showed an absence of PgR (P < 0.05), and there was a tendency for PgR-negative tumors to be larger than PgR-positive ones. No correlation was found between PgR status and edema. It is concluded that PgR status in meningiomas is related to tumor differentiation and may be of prognostic value with regard to biological behavior and clinical outcome.

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.

Isoform-specific immunological detection of newt retinoic acid receptor delta 1 in normal and regenerating limbs

Retinoic acid (RA) exerts a variety of effects on the regenerating urodele limb including positional respecification of the blastema. The major RA receptor expressed in the newt limb and blastema is the delta 1 isoform and, in order to detect delta 1 in this context, we have made five affinity-purified antibodies against fusion proteins and peptides from non-overlapping regions of the molecule. These antibodies have been evaluated by reaction with transfected COS-7 cells, newt limb cells in culture and newt limb tissue sections. The most informative antibodies were RP6, directed against N-terminal region A sequence, and RP8, directed against C-terminal sequence. In western blots of blastemal extracts, delta 1 protein was detected as two major bands of immunoreactivity at positions consistent with the employment of two candidate methionine initiators identified by cDNA sequencing. Staining of adult limb sections with RP6 and RP8 showed reactivity in half of the nuclei in epidermal and mesenchymal tissues, a heterogeneity that was observed with adjacent nuclei in muscle fibres. In the regenerating limb, nuclei in the blastemal mesenchyme and wound epidermis were strongly reactive, although no axial variation in expression was detected.

Quantitative microscopical and confocal laser scanning microscopy for intermediate endpoint biomarkers in breast cancer: potential and reproducibility

Diagnostic quantitative pathological (QP) determinations are increasingly used in our hospital. The number of requests for QP for reference materials is rising rapidly. This is understandable; quantitative assessments have a strong prognostic value and can be very reproducible, depending on the care taken with a number of factors including cell and tissue processing, application of the appropriate stains, and the measurement protocol used. As to the latter, systematic random sampling gives the best intra- and interobserver agreement (with correlation coefficients between observers for certain features > or = 0.94). Flow cytometric determinations are often regarded as more reproducible than interactive morphometry due to the high speed of the assessments, the large number of objects measured per specimen, and the lack of observer interaction. Indeed, flow cytometrically assessed DNA ploidy is very reproducible, even though the % S-phase fraction is much more variable. Unlike image cytometry (ICM), visual inspection of cells is not easily accomplished with flow cytometry (FCM). With ICM, the fully automated measurement of DNA in thousands of cells is possible in 3-5 minutes, with a very low coefficient of variation (< or = 2% for the diploid and tetraploid peak of liver cell nuclei). ICM also allows measurement of texture features. However, quantitative immunohisto/cytochemical determinations may not always be as reproducible as sometimes believed. Recently, we found large variations in the measurements, made by a commercially available image processing instrument, of the estrogen and progesterone receptors, Ki-67, cathepsin D, and neu protein overexpression in breast cancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Progesterone receptor determined by immunocytochemical and biochemical methods in human breast cancer

Immunocytochemical assay (ICA) of the progesterone receptor (PgR) was performed on 152 patients with stage I-II breast cancer. We employed the rat monoclonal antibody KD-68 and a peroxidase/antiperoxidase displaying system. The results obtained by ICA (Pg(RICA)) were compared with those by the biochemical dextran-coated charcoal assay (PgRDCC). Comparing the two methods we found an overall agreement (accuracy) of 77.5%, a PgR(ICA) sensitivity of 83.5% and a specificity of 73%. Both methods were significantly associated with oestrogen receptor expression, detected by DCC (P less than 0.001 for PgRDCC and P = 0.0014 for PgR(ICA)). No significant association was found between PgR(ICA) or PgRDCC and the other clinicopathological features analysed. After a median follow-up of 36 months, the overall survival probability was 91% in PgRDCC-positive versus 81.5% in PgRDCC-negative patients (log-rank test, chi 2 = 0.91) compared to 87.5% in PgR(ICA)-positive versus 82% in PgR(ICA)-negative ones (log-rank test, chi 2 = 0.93). Disease-free survival probability was 74.5% in both PgRDCC-positive and PgRDCC-negative patients (log-rank test, chi 2 = 0.02) compared to 78% in PgR(ICA)-positive versus 71.5% in PgR(ICA)-negative cases (log-rank test, chi 2 = 0.37). The present study demonstrates that ICA is a reliable method to detect PgR, correlating well with the DCC assay. Moreover, the ICA assay seems to provide clinical information complementary to the biochemical method. The definition of its prognostic value in operable breast cancer needs additional studies, particularly in node-negative patients.

Densitometric and morphometric study of immunocytochemical estrogen receptors detection in breast carcinomas

Immunohistochemical quantitative evaluation of estrogen receptors (ER) detected in tissue sections from 30 breast tumors by monoclonal antibody was performed using a densitometric method. In particular, ER concentration was calculated by nuclear mean optical density (nMOD), while heterogeneity in ER content was calculated by the coefficient of variation (CV) of the nuclear optical density histogram. Tumors which showed more than 60% of positive cells had a mean value of ER-nMOD of 0.116 +/- 0.002 a.u. and of ER-CV of 33.74 +/- 0.68. Tumors which showed 30% to 60% of positive cells had a mean value of ER-nMOD of 0.082 +/- 0.006 a.u. (arbitrary units) and of ER-CV of 36.25 +/- 3.44. Tumors showing less than 30% of positive cells had ER-nMOD of 0.052 +/- 0.009 a.u. and ER-CV of 48.49 +/- 5.61. These results indicate that the greater the concentration the lower the ER heterogeneity within the tumor sample. No significant differences between ER-ICA results, nuclear size and form factors were found.

Immunobiochemical assay for determination of nuclear steroid receptors

Knowledge of receptor status is important for therapeutic strategies in hormone-dependent tumors. Therefore, methods specifically predicting biological response to endocrine therapy are essential. We investigated the receptor modulation of two breast tumors and one endometrial tumor in the nude mice model after injection of 20 micrograms 17 beta-estradiol. To differentiate the unoccupied and the occupied receptor sites, we used the enzyme immunoassay (EIA) for estrogen receptors (ER) under low- and high-salt conditions. With low-salt extraction we found a sharp decrease of the ER-EIA values within the first hour after estradiol treatment. This decrease continued for 24 hr until recovery to pretreatment levels occurred. In contrast, the ligand-receptor complexes tightly bound to acceptor sites on the DNA increased more than three times within 1 hr. These high levels could be measured for almost 12 hr, and then pretreatment levels were reestablished. The PgR-EIA values under low-salt conditions increased 10-fold within 12 hr, indicating an intact receptor mechanism. We conclude that this immunobiochemical method is a useful tool in determining receptor sites: those both unbound and those tightly bound to nuclear acceptors.

Determination of estrogen receptors in paraffin-embedded tissue. Techniques and the value in breast cancer treatment

Estrogen receptor (ER) analysis in breast cancer has been used in three clinical situations: to select patients with advanced breast cancer for hormonal therapy, as a prognostic parameter, and for selection of women with early breast cancer to adjuvant hormonal treatment. ER has traditionally been measured using labelled hormone in binding assays--often in dextran-coated charcoal assays (DCC). Monoclonal antibodies to ER has permitted development of a solid phase enzyme immunoassay (ER-EIA) used for quantitative determination of ER in tissue homogenates, and have also been used for determination of ER using an immunohistochemical assay in frozen sections (ER-ICA) or in formalin-fixed, paraffin-embedded tissue (ER-PAR). A large number of studies has compared ER-EIA with ER-DCC assays. There is a good linear correlation between the two types of assay but ER-EIA measure more ER and classify a larger fraction of tumors ER-positive than conventional ER assays. Lack of clinical data makes the significance of this uncertain. Numerous studies have reported on the correlation between ER-ICA and ER-DCC or ER-EIA. There is a good correlation among the assays on classification of ER status with a median 86% concordance, but a somewhat poorer correlation between semiquantified ER of immunohistochemical assays and ER determined by the quantitative methods (median coefficient of correlation 0.67). There is a large variation in the cut-off level for definition of ER-positive in immunohistochemical assays emphasizing the need for quality control studies. The major problem involved in ER analysis in paraffin-embedded tissue is a considerable loss of immunoreactivity compared to sections from frozen tissue. This can partly be overcome by modifications of the immunohistochemical technique using enzyme pretreatment and other amplification systems, but the sensitivity of ER-PAR remains lower than ER-ICA despite these modifications, and the ER status is less reliably determined in tumors with low ER contents (< 100 fmol). The prognostic value of ER-PAR was evaluated with a multivariate analysis. The endpoint was disease-free interval in systemically untreated patients with early breast cancer, and the variables used were: ER-DCC, ER-PAR, age, tumor size, tumor grade, and nodal status. A total of 133 patients from the Danish Breast Cancer Cooperative Group's (DBCG) 77c protocols had a complete set of variables. The analysis showed that only nodal status, ER-DCC, and tumor grade were significant and independent prognostic variables. An overview of larger multivariate studies on mainly node-negative patients failed to show independent prognostic significance of ER-DCC.(ABSTRACT TRUNCATED AT 400 WORDS)

A rapid method for the quantitation of estrogen receptors in small amounts of tissue

A rapid and highly reproducible protocol which permits the detection of quantities of estrogen receptor as low as 5 fmol/mg protein is described. The separation of free and receptor-bound hormone is achieved by specific immunoprecipitation of the hormone-receptor complex. This procedure can be performed without perturbing the equilibrium of the binding reaction.

Comparison of estrogen receptor and epidermal growth factor receptor content of primary and involved nodes in human breast cancer

Estrogen receptors (ER) and epidermal growth factor receptors (EGFR) in the tumor cells of breast cancer tissues (primary tumors) and metastatic lymph nodes (involved nodes) were analyzed by immunocytochemical study in 19 patients; 12 were ER positive, and seven were ER negative. Microscopic study was used to determine the percentage of positive cells and the staining index. The percentage of EGFR-positive cells and the EGFR staining index were higher in the ER-negative primary tumors than ER-positive primary tumors. In ER-positive cases, both the number of ER-positive cells and ER content per cell was less in the involved nodes than in the primary tumors, whereas the number of EGFR-positive cells and EGFR content per cell was greater in affected nodes. On the other hand, in the ER-negative cases the number of EGFR-positive cells and EGFR content per cell remain almost unchanged between the primary tumors and involved nodes. The authors supposed a probability, in this study, that estrogen may exert inhibitory action on EGFR production through binding to ER.

Hormone sensitivity in breast cancer: influence of heterogeneity of oestrogen receptor expression and cell proliferation

The percentage of oestrogen receptor (ER) positive cells in a series of 118 breast cancers has been examined by immunohistochemistry in relation to patients' response to endocrine therapy. Positive and negative predictive values have been used to calculate appropriate cut-off points. The rate of response to treatment was significantly higher in women with receptor positive tumours, especially where the tumours contained more than 70% positive cells. Tumours that were apparently negative for ER expression rarely responded to endocrine therapy. The hormone sensitivity of ER positive breast cancer was also influenced by the rate of tumour cell proliferation, with tumours expressing high levels of Ki67 immunostaining rarely responding to therapy.