Immunohistological study of oestrogen receptors in breast carcinomas that are biochemically receptor negative

The epidemiology of triple-negative breast cancer, including race

OBJECTIVE

Predictors of intrinsic breast cancer subtypes, including the triple-negative (TN) subtype, are largely unknown. We evaluated whether anthropometrics, demographics, and reproductive history were associated with distinct breast cancer subtypes.

METHODS

Invasive breast tumors from a population-based case-control study of 476 (116 black and 360 white) Atlanta women aged 20-54, diagnosed between 1990 and 1992, were centrally reviewed and immunohistochemically analyzed for estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2); then grouped [TN (ER-PR-HER2-); ER-PR-HER2+; ER/PR+HER2+; ER/PR+HER2- (case-only reference group)]. Data were from interviews and anthropometric measurements; adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression, including both case-only and case-control comparisons.

RESULTS

From the case-only analyses and compared with the ER/PR+HER2- subtype, women with TN tumors were more likely to be obese than normal/underweight [OR = 1.89 (95% CI = 1.22, 2.92)]. Regardless of HER2 status, ER-PR- tumors were associated with black race, young age at first birth, having a recent birth, and being overweight.

CONCLUSIONS

Distinct breast cancer subtypes have unique sociodemographic, anthropometric and reproductive characteristics and possibly different pathways for development.

Race and triple negative threats to breast cancer survival: a population-based study in Atlanta, GA

BACKGROUND

Breast cancers with a triple negative tumor (TNT) subtype (as defined by lacking protein expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)) preclude the use of available targeted therapies and may contribute to poor outcome and to the historically poorest survival observed among African-American (AA) women. This study examines association of the ER/PR/HER2 subtypes with race and breast cancer survival.

METHODS

Breast tumors from a population-based cohort of 116 AA and 360 white Atlanta women aged 20-54, diagnosed from 1990 to 1992 were centrally reviewed and tested by immunohistochemistry. Multivariate survival analyses within subtypes (TNT, ER-PR-HER2+, ER+/PR+HER2+, ER+/PR+HER2-) were conducted using weighted Cox regression and included socio-demographic, prognostic, and treatment factors.

RESULTS

TNTs were more prevalent among young women and particularly among AA women (Odds Ratio [OR] = 1.9, 95% Confidence Interval [CI] 1.2-2.9), adjusting for age, stage, grade, and poverty index. Overall mortality was higher for AA women (Hazard Ratio [HR] = 1.9, 95% CI, 1.5-2.5) and differed by subtypes (P < 0.001). Within the TNT subtype, racial differences in survival persisted, after additional adjustment for treatment and comorbidities (HR = 2.0, 95% CI 1.0-3.7). TNTs were uniquely associated with high expression of p16, p53, and Cyclin E; and low Bcl-2 and Cyclin D1 expression.

CONCLUSIONS

The high prevalence of TNTs among younger women and particularly younger AA women, along with unique protein expression patterns and poorer survival, suggests varying gene-environment etiologies with respect to age and race/ethnicity and a need for effective therapies.

Racial differences in the expression of cell cycle-regulatory proteins in breast carcinoma

BACKGROUND

African-American (AA) women are more likely to be diagnosed with an advanced stage of breast carcinoma than are white women. After adjustment for disease stage, many studies indicate that tumors in AA women are more likely than tumors in white women are to exhibit a high level of cell proliferation and features of poor prognosis. The purpose of the current study was to compare tumor characteristics and cell cycle alterations in AA women and white women that might affect the aggressiveness of breast carcinoma.

METHODS

The study included 124 AA and 397 white women, ages 20-54 years. These women were enrolled in a case-control study in Atlanta, Georgia, between 1990 and 1992. Breast tumor specimens obtained from these women were centrally reviewed for histologic characteristics and evaluated for expression of estrogen and progesterone receptors (ER/PR), c-ErbB-2, Ki-67, p53, cyclin E, cyclin D1, p27, p16, pRb, and p21 by immunohistochemistry. Logistic regression models were used to assess the age- and stage-adjusted associations of various tumor characteristics with race.

RESULTS

The odds of a breast carcinoma diagnosis at a younger age and at a later stage were higher for AA women than for white women. After adjustment for disease stage and age at diagnosis, AA women also were found to have increased odds of having a higher-grade tumor, a higher mitotic index, marked tumor necrosis, ductal histology, loss of ER and PR, overexpression of cyclin E, p16, and p53 and low expression of cyclin D1 at diagnosis.

CONCLUSIONS

The observed differences between tumor specimens obtained from AA women and tumor specimens obtained from white women, independent of stage and age at diagnosis, indicated that race may be a determinant, or a surrogate for other determinants, of aggressive breast carcinoma and specific cell cycle defects.

Male breast cancer: a retrospective study with immunohistochemical analysis of hormone receptor expression

Of twenty-two cases of breast carcinoma diagnosed in men in Singapore since 1969, 17 were classified as infiltrative ductal carcinoma, three as papillary and one as mucinous carcinoma. The remaining case could not be classified and further immunohistochemical workup suggested the possibility of metastasis from an occult prostatic primary. Fourteen cases that were staged revealed a majority of seven (50%) cases in Stage II, with three (21%) Stage I, one (8%) Stage III and three (21%) Stage IV cases. Estrogen and progesterone receptor (ER and PR) expression was determined in 20 cases using immunohistochemical staining of archival paraffin embedded tissue blocks, which demonstrated ER and PR positivity in 65% of the cases respectively.

Comparison of estrogen receptor determinations by a biochemical ligand-binding assay and immunohistochemical staining with monoclonal antibody ER1D5 in females with lymph node positive breast carcinoma entered on two prospective clinical trials

BACKGROUND

The measurement of estrogen receptors (ER) in breast cancer specimens has traditionally been assessed with a dextran-coated charcoal assay (DCCA). More recently the immunohistochemical staining (IHC) method has gained increasing popularity because of its ability to use fixed tissue, assess needle biopsies, and reduce cost. Controversy exists over the accuracy of IHC compared with that of DCCA in determining ER. We compared these two techniques using tumor tissue obtained from a large group of females with lymph node positive breast carcinoma with long term follow-up.

METHODS

Breast carcinoma tissue was obtained from a large group of females with node positive breast carcinoma participating in two adjuvant chemotherapy trials. ER was determined by the traditional DCCA method and by IHC using the ER1D5 antibody. Disease free survival (DFS) and overall survival (OS) were assessed by each of these methods.

RESULTS

ER status was determined by DCCA and IHC in tumor tissue obtained from 316 females. A concordance of 79% was observed for the determination of ER-positive tumors. Of the discordant results, the majority of DCCA-negative, IHC-positive tumors could be explained by a low level of DCCA positivity (< 10 fmol) or IHC staining of nonmalignant cells. A much higher rate of discordant results was observed in premenopausal females. Of the DCCA-negative, IHC-positive patients 97% were premenopausal and of the DCCA-positive, IHC-negative patients 79% were premenopausal. ER by DCC appears to perform better than ER by IHC as a prognostic factor in terms of DFS and OS.

CONCLUSIONS

When compared with DCCA, IHC with monoclonal antibody ER1D5 appears to be a reasonable substitute for the determination of ER. Although DCCA appeared to perform better as a determinant of prognosis, ER detection is used primarily for deciding on hormonal therapy. Review of discordant cases indicates IHC may more accurately reflect the ER status of malignant cells in some patients. Attention must be paid to quality control considerations in performance of IHC staining.

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.

Expression of cathepsin D and estrogen receptor in male breast carcinoma

Male breast cancer is probably hormone dependent, but studies are few due to the rarity of this tumor. We have studied 21 cases of male breast cancer immunohistologically for estrogen receptor (ER) and cathepsin D (CD) expression. In carcinoma of the female breast ER expression is associated with longer patient survival and responsiveness to hormonal manipulation. Cathepsin D is an estrogen-regulated lysosomal protease with proteolytic and mitogenic properties whose presence denotes a functioning ER. In our series of male breast carcinomas 86% were ER positive and 62% were CD positive; this compares with typical figures of 50% and 66%, respectively, for female breast cancer. We observed no trends between expression of ER and CD and patient survival; immunostaining for ER and CD is unlikely to be clinically useful in carcinoma of the male breast. The high rate of ER positivity in males suggests that male and female breast carcinomas are biologically different tumors.

Oestrogen and progesterone receptors in screen-detected breast carcinoma: an immunohistological study using paraffin sections

The presence of oestrogen and progesterone receptors was studied in paraffin sections of 81 screen-detected breast carcinomas using the monoclonal antibodies ER-ICA and PgR-ICA (Abbott) and the immunoperoxidase technique. The immunohistological results were compared with the results of the standard dextran-coated charcoal biochemical assay in 28 tumours which were big enough to provide tumour tissue for this assay. Sixty-three cases (78%) were oestrogen receptor positive and 62 (77%) were progesterone receptor positive. There was no statistical difference between receptor positivity in palpable or impalpable, in situ or invasive tumours. In the 28 cases where the biochemical assay was carried out, the two methods gave similar results in 23 (82%) and 21 (75%) tumours for oestrogen and progesterone receptors respectively. The majority of the remaining tumours, with one exception, were positive with immunohistology and negative with biochemistry. A good correlation was also present between the mean numerical biochemical values and the semiquantitative histological scores for both receptors. It is concluded that assessment of receptor status of small screen-detected carcinomas is feasible using routinely processed paraffin sections. There is reasonably good correlation with the results obtained by the standard dextran-coated charcoal biochemical assay, but more genuine receptor positive cases are detected by immunohistology.

Oestrogen receptor and epidermal growth factor receptor expression in male breast carcinoma

Male breast carcinomas are probably hormone-dependent, but receptor studies are few because this is a relatively rare tumour. We have studied 21 cases of male breast carcinoma immunohistochemically for oestrogen receptor (ER) and epidermal growth factor receptor (EGFR) expression employing the antibodies ER-ICA and 12E on formalin-fixed, paraffin-embedded material. In our series, 86 per cent of male breast cancers were ER-positive and 76 per cent were EGFR-positive. Male breast carcinomas do not exhibit the inverse correlation between ER and EGFR expression that characterizes female breast carcinomas. Owing to the limitations of a small series, we were unable to comment on the relationship between ER and EGFR expression and patient survival. However, the relatively high incidence of ER expression may provide a growth advantage for this tumour in a male environment characterized by low levels of oestrogen. In addition, high EGFR expression may also contribute to a poor prognosis independent of ER status.

Demonstration of progesterone receptors in paraffin wax sections of breast carcinoma

Several immunohistological methods for the demonstration of progesterone receptors were tried on routinely processed paraffin wax sections of breast carcinoma, using Abbott's PgR-ICA monoclonal antibody. The best results were obtained with the avidin-biotin-immunoperoxidase complex method with no prior trypsinisation or DNAse digestion, and with imidazole added to the final diaminobenzidine developing solution. A simple semiquantitative scoring system was used to assess the staining results which were then compared with the results obtained by a standard dextran-coated charcoal biochemical assay. Of 31 cases examined, the results of the two methods were concordant in 25 (81%) of cases. This is near the higher end of the concordance range obtained by several other authors using frozen sections. The discordance encountered in a few cases was possibly the result of sampling errors which are more likely to occur with the chemical rather than the histological method. It is concluded that the method described here is fairly reliable and would greatly simplify the process of assessment of progesterone receptors in breast, and possibly other tumours.