Stability of oestrogen receptor status in sequential biopsies from patients with breast cancer

Effect of interferon alpha-2a on hormone receptor status in patients with advanced breast cancer

The aim of this study was to assess the effect of recombinant interferon alpha-2a (rh-IFN) on estrogen (ER) and progesterone (PR) receptor expression in patients with advanced breast cancer and the evaluation of the effect of rh-IFN pretreatment on response to endocrine therapy with tamoxifen (TAM). Between June 1990 and November 1992, 20 patients with disseminated breast cancer and with metastatic skin nodules suitable for biopsy were entered into this study. Eighteen assessable patients underwent biopsy before and 2 weeks after treatment with rh-INF. rh-INF 3 x 10(6) IU were administered subcutaneously per day. Patients with ER expression at second biopsy were subsequently treated with 20 mg TAM daily. One patient had rapid disease progression and died before rebiopsy could be performed, and an additional patient refused second biopsy. All other patients were considered assessable. Thirteen patients showed ER expression before rh-IFN treatment, and 5 PR presented with expression. Rh-IFN increased ER expression in three patients and PR in four patients. No change was observed in 8 patients for ER and in 12 patients for PR. ER expression decreased in seven patients and PR expression decreased in two patients, respectively. Two patients showed a partial remission after subsequent treatment with TAM. Adverse reactions caused by rh-IFN were mainly flu-like symptoms. In this trial we found no systematic impact of rh-IFN on hormone receptor expression and, subsequently, on the response rate in patients with advanced breast cancer.

Absence of progesterone receptor associated with secondary breast cancer in postmenopausal women

The relationship between expression of receptors for oestrogen and progesterone (ER and PR) and disease progression in breast cancer was investigated by comparing immunocytochemical determinations of ER and PR in fine needle aspirates from primary and secondary breast tumours. Rates of receptor expression were significantly higher in primary than in secondary lesions: for ER 63.3% (n = 689) compared with 45.3% (n = 223), and for PR 53.7% (n = 443) compared with 33.1% (n = 121). The effect of menopausal status was examined by subdividing the patient cohort into those over or under the age of 50 years. In both instances, ER expression in secondary tumours was relatively low; however, only postmenopausal patients had significantly lower rates of PR expression in secondary tumours. Consistent with this, an increase in the ER+PR- profile in secondary tumours compared with primary cases from postmenopausal patients was seen, and in a multivariate analysis, a specific absence of PR expression in secondary tumours was revealed. Comparison of ER and PR expression in simultaneously sampled primary tumours and lymph node metastases from the same patient showed that receptor expression was stable with progression to a metastatic site as results were concordant for ER in 92% (n = 88) and PR in 93.8% of cases (n = 65). These results suggest that absence of PR expression in primary breast cancer is associated with disease progression and may be a marker of an aggressive tumour phenotype.

Estrogen receptor status of breast cancer: a marker of different stages of tumor or different entities of the disease?

Breast cancer can be divided into two types according to the estrogen receptor (ER) level of the tumor: ER-positive and ER-negative. Two hypotheses have been raised about the relationship between ER-positive and ER-negative breast tumors. One hypothesis considers ER status as an indicator of a different stage of the disease. The other regards ER-positive and ER-negative tumors as different entities. For both etiological and biological studies of breast cancer it is important to know which hypothesis is correct. In this paper, we review evidence for and against each hypothesis and suggest issues to be addressed in future studies.

Estrogen and progesterone receptor content in bilateral breast cancer

Estrogen and progesterone receptor content was determined in 34 patients with synchronous and 23 patients with asynchronous bilateral breast cancer. Steroid receptor content was measured quantitatively by DCC method. It was shown that progesterone receptor content could not be predicted, as well as, that steroid receptor content of the second tumor significantly influenced the development of asynchronous bilateral breast cancer. The high discordance rate concerning histologic type between two tumors within synchronous as well as asynchronous biopsies was observed. The obtained results indicate that both synchronous and asynchronous bilateral breast tumors may be considered as biologically different tumors whose both steroid receptor levels should be determined whenever possible.

Estrogen and progesterone receptor concordance between primary and recurrent breast cancer

Estrogen and progesterone receptor status in breast cancer can determine therapeutic options and may provide prognostic information. The purpose of this study is to compare the concordance of the primary breast cancer steroid hormone receptor status to that of the recurrent breast cancer and to determine whether the type of second lesion (local recurrence, second primary, or metastatic lesion) and adjuvant therapy received changed the receptor concordance. The records of eighty-three patients with estrogen receptor (ER) analysis available for primary (p) and recurrent (r) breast cancer for 1976-1990 were reviewed. In addition, 32 of these patients also had available progesterone receptor (PR) values for primary and recurrent breast cancers. Statistical evaluation was performed by chi-square, Student's t-test, and Wilcoxon signed-rank test. ER concordance (primary/recurrent, p/r) was identified in 59/83 (71%) patients; PR concordance was identified in 18/32 (56%) patients. Whether the second lesion was a local recurrence, second primary, or a metastatic lesion did not affect ER concordance or PR concordance. Adjuvant chemotherapy, hormonal therapy, or radiation therapy, either alone or in combination, did not affect ER or PR concordance. The disease-free survival (DFS) for patients with ER (p+)/(r-) (primary receptor positive/recurrent receptor negative) was significantly shorter than those with ER (p-)/(r+)(27.6 +/- 7.4 months versus 50.6 +/- 7.6 mo, P = 0.04). The DFS for PR (p+)/(r-) patients was 28.8 +/- 7.9 months compared to the DFS of 46.8 +/- 11.8 months for PR (p-)/(r+) patients (P = NS). A significantly shorter DFS for ER (p+)/(r-) patients compared to ER (p-)/(r+) patients and a trend towards a shorter DFS for PR (p+)/(r-) patients compared to PR (p-)/(r+) patients may reflect a loss of hormonal regulation or an increase in cancer aggressiveness.

Type I IGF receptor and acquired tamoxifen resistance in oestrogen-responsive human breast cancer cells

Tamoxifen inhibited the oestrogen-stimulated proliferation of MCF-7 cells but had little effect on the oestrogen-stimulated proliferation of two tamoxifen-resistant variants (RL-3 and AL-1). The lack of oestrogen antagonist activity in the resistant cells was largely a result of an increased oestrogen agonist activity of tamoxifen on cell proliferation. Proliferation of the tamoxifen-resistant cells was also stimulated by 4-hydroxytamoxifen but not by ICI 164,384, a structurally distinct pure anti-oestrogen. Tamoxifen does not have increased oestrogen agonist activity for the induction of a series of oestrogen-regulated RNAs, and this suggests that the increased agonist activity may be restricted to key components involved in the proliferative response. Tamoxifen-stimulated cell proliferation was dependent on insulin-like growth factor I (IGF-1) in the resistant cells, suggesting that tamoxifen stimulates cell proliferation by sensitising cells to the proliferative effects of IGF-1. This may involve induction of the type-I IGF receptor.

Measurement of steroid hormone receptors in breast cancer patients on tamoxifen

Estrogen (ER) and progesterone receptor (PgR) positive breast tumors often respond to tamoxifen, but ultimately progress as they become tamoxifen resistant. An accurate assessment of receptor status in specimens from tamoxifen-resistant patients could help to understand potential mechanisms of resistance and to predict response to second line hormonal therapies. However, since tamoxifen itself can affect ER and PgR determinations, assay results can be misleading. We measured ER and PgR by both ligand binding (LBA) and immunohistochemical (IHC) assays in 34 tumors from patients on tamoxifen, 30 of whom were displaying resistance to the drug. These tumors were classified into several receptor phenotypes. Eleven patients, 8 of whom were clearly progressing, expressed both receptors while on tamoxifen. ER was significantly less often negative when measured by IHC, suggesting that ER status by LBA was falsely negative in this group due to receptor occupancy by tamoxifen. Six patients had no detectable ER by LBA or IHC but still expressed PgR. The presence of PgR suggests that ER could still be functional, though undetectable, in these tumors, or that PgR is constitutively expressed by them. Finally, 12 patients were ER and PgR-negative by both assays, suggesting hormonal independence as the mechanism for resistance in this group. In a subset of patients with receptor assays both prior to tamoxifen and at the time of progression while taking the drug, we found that most ER-positive tumors converted to an apparent ER-negative status when assayed by LBA, while PgR status frequently remained unchanged. The continued expression of ER and/or PgR in many patients with tumor progression on tamoxifen indicates that mechanisms for resistance other than receptor loss are common in breast cancer.

Change in the oestrogen receptor status of breast cancer with age--comparison of two types of assay

The oestrogen receptor (ER) is considered to be an essential component of the mechanism of response of a breast tumour to endocrine therapy, but ER measurements have proved to have only modest predictive value. In the present study, we have examined ER status by both immunocytochemical assay (ER-ICA) on a fine needle aspirate and by radioligand-binding assay (DCC) on an excised portion of tumour. There was a correlation between the ER level detected by the two assays (Spearman's r = 0.77 for DCC versus ER-ICA staining intensity, r = 0.70 for DCC versus ER-ICA percentage of cells stained, P < 0.0001, n = 137 in each case). Each assay showed an increasing proportion of ER+ve results with increasing patient age. In the case of ER+ve tissues only, while ER concentration by DCC assay increased steadily with age (r = 0.39, P < 0.0001, n = 108), the ER-ICA assay revealed that, staining intensity increased with age (r = 0.26, P = 0.001, n = 149) but the percentage of cells stained did not (r = 0.08, P = NS, n = 149). It is concluded that increasing endocrine responsiveness with advancing age could reflect the increasing proportion of ER+ve tumours with increased levels of ER per cell (as indicated by staining intensity) rather than increasing proportion of ER+ve cells.

The prognosis of breast cancer patients in relation to the oestrogen receptor status of both primary disease and involved nodes

Nodal involvement is accepted as the best single marker of prognosis in breast cancer. However, there is little information on the sub-division of node-positive patients according to the oestrogen receptor status of the nodal tissue. We have previously reported (Eur. J. Ca. 1987, 23, 31) that, in almost all cases, involved nodes are only oestrogen receptor positive (ER+) in patients whose primary tumours are uniformly ER+. This paper presents clinical follow-up on a larger group of patients with node positive breast cancer. For each patient, both soluble and nuclear receptor concentrations were determined in three separate parts of the primary tumour and in at least one involved node (we have previously defined tumours which contained ER in all six fractions of the primary as HS++, those lacking receptor in some fractions as HS+- and wholly receptor negative tumours as HS--). Median follow-up time was 71.5 months. As expected, patients whose tumours were HS++ had a significant (P less than 0.008) survival advantage. More importantly, patients with ER in both the soluble and nuclear fractions of their involved nodes survived significantly (P less than 0.003) longer than those with ER- nodes. Thus, full oestrogen receptor status of involved nodes will give sufficient prognostic information when adequate primary tissue is not available.

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)

Variations in the content of steroid receptors in breast cancer. Comparison between primary tumors and metastatic lesions

Steroid receptors were determined by the dextran-coated charcoal method in 193 breast cancer patients in different clinical stages of disease. Quantitative estrogen and progesterone values in primary tumors (n = 69) were compared with receptors in regional lymph node metastases (n = 28) and in distant malignant deposits (n = 65). The groups including receptor values from primaries and regional lymph node metastases (n = 15) and from primaries and distant metastatic lesions (n = 16) in the same patients were also analyzed. The obtained results indicated relative stability of both receptors in loco-regional disease, but with a tendency towards lower receptor values in lesions from advanced disease. This tendency is probably caused by the disease progression itself, but the influence of radio- or chemotherapy cannot be excluded.

Oestrogen and progesterone receptor status in bone biopsy specimens from patients with breast cancer

Of 16 breast cancer patients with histologically proven, tumour-infiltrating biopsy specimens most had low ER and PR values; the ER and PR contents varied between 0 and 135 and 0 and 44 fmol/mg protein, respectively. With the conventional clinical threshold of 10 fmol/mg protein, 8 specimens (50%) were ER-PR-, 4 (25%) ER-PR+, 3 (19%) ER+PR+ and 1 (6%) ER+PR-. ER levels were significantly lower in the tumoral bone lesion compared with the primary tumour. For 15 patients with negative biopsies and without endocrine treatment, ER and PR concentrations were quantifiable (2 fmol/mg protein or more) in 9 (60%) and 11 cases (73%), respectively. 8 of 9 patients over 55 (89%) were ER+ (2 fmol/mg protein or more). Conversely, for patients under 55, 1 of 6 (17%) was ER+ (P less than 0.001). Results for PR were similar. These data strongly suggest that steroid receptors are present in healthy bone tissue.

Epidermal growth factor receptor (EGFr) status associated with failure of primary endocrine therapy in elderly postmenopausal patients with breast cancer

We have used primary endocrine therapy for 61 elderly women with operable breast cancer (median age 77 years). Eleven patients (18%) had complete and 24 (39%) partial tumour regression, 12 (20%) had stable disease for a minimum of six months and 14 (23%) no response. Salvage surgery was undertaken in the 14 with no response and 8/9 with progressive disease following initial response, thus samples were available from relapse patients only. Assays for EGFr (two point radioreceptor assay) and oestrogen receptors (ER) (dextran coated charcoal method and an immunohistochemical method) were performed on 20/22 patients. Ten of these 20 tumours were EGFr+ (greater than 10 fmol mg-1 binding) and 9/13 patients progressing within six months had EGFr+ tumours. 15/22 were available for ER evaluation and there was no such association with ER status. EGFr status was also associated with early recurrence after surgery and death in the endocrine failure group (P less than 0.005 and P less than 0.05 respectively). Of a control population of 33 patients (median age 72 years) treated by primary surgery, only 6 were EGFr+. In this group early relapse was predicted by EGFr status, but not by ER status (median disease free survival for EGFr+ patients 15 months, and for EGFr- patients 40 months, P less than 0.01, logrank test). There was a significantly higher proportion of EGFr+ tumours in the endocrine failure group compared with the control population (P less than 0.001). EGFr status is a marker for rapid early progression on primary endocrine therapy and the development of non-excisional methods of EGFr analysis would allow better directed therapeutic decisions.

Relationship between estrogen receptor status in the primary tumor and its regional and distant metastases. An immunohistochemical study in human breast cancer

Treatment of metastatic breast cancer based on the estrogen receptor content (ER) of the primary tumor builds on the assumption that the ER status of the primary tumor and the metastases are largely equal. Studies addressing this question have used ligand-binding assays for ER determination and have consequently been subject to the limitations of this technique. Reported disparity rates have been 20%. In order to avoid some of these limitations, we used an immunohistochemical assay in paraffin-embedded tissue. Among a total of 92 examined regional lymph node metastases, ER status was equal with that of their 37 primaries in 84 cases (91%). Semiquantified ER content was significantly correlated in primary tumor and the metastases (r = 0.67, p less than 0.001). Among a total of 51 distant metastases, equal ER status was found in 44 (86%) cases and a quantitative relationship could not be established. Disparities can be due to methodological errors in the histochemical assay or tumor heterogeneity.