Oestrogen receptors and breast cancer: current status

Correlation of expression of hormone and HER2 receptors with various clinico-pathological prognostic parameters and with each other in malignant breast lesion

BACKGROUND

Estrogen receptors (ER), progesterone receptors (PR) and the human epidermal growth factor receptor-2 (HER2) are basic breast cancer molecular markers that are also best recognized prognostic factors and predictors of type of targeted therapy to be given. The objectives are to study the correlation of expression of hormone and HER2receptors with various clinico-pathological prognostic parameters like patient's age at diagnosis, menopausal status, tumor size, histological grade and lymph node status of tumor and with each other in malignant breast lesion.

METHODS

For this study histopathology (HP) and immunohistochemistry (IHC) slides of excised specimens of 330 female patients with a palpable breast lump deposited to the pathology department of a hospital as a part of routine diagnostic procedure, were evaluated under the guidance of trained doctors who have minimum 5 years of experience in oncopathology. The author has no direct involvement with patients, informed consent was not necessary and data were collected after getting permission from concerned authority.

RESULTS

This study finds significant relationship between hormone receptors and all clinico-pathological prognostic parameters taken for comparison except age at diagnosis. HER2 status has significant relationship with all clinico-pathological prognostic parameters; hormone and HER2 status suggests an inverse relationship.

CONCLUSIONS

Mien of hormone receptors expression in breast cancer is related with better prognostic factors such as older age, postmenopausal status, smaller tumor size, low histological grade and negative lymph node status, however the opposite is correct for HER2. Hormone receptors and HER2 have an inversely proportionate relationship with each other.

Breast cancer development and progression: Risk factors, cancer stem cells, signaling pathways, genomics, and molecular pathogenesis

As the most commonly occurring cancer in women worldwide, breast cancer poses a formidable public health challenge on a global scale. Breast cancer consists of a group of biologically and molecularly heterogeneous diseases originated from the breast. While the risk factors associated with this cancer varies with respect to other cancers, genetic predisposition, most notably mutations in BRCA1 or BRCA2 gene, is an important causative factor for this malignancy. Breast cancers can begin in different areas of the breast, such as the ducts, the lobules, or the tissue in between. Within the large group of diverse breast carcinomas, there are various denoted types of breast cancer based on their invasiveness relative to the primary tumor sites. It is important to distinguish between the various subtypes because they have different prognoses and treatment implications. As there are remarkable parallels between normal development and breast cancer progression at the molecular level, it has been postulated that breast cancer may be derived from mammary cancer stem cells. Normal breast development and mammary stem cells are regulated by several signaling pathways, such as estrogen receptors (ERs), HER2, and Wnt/β-catenin signaling pathways, which control stem cell proliferation, cell death, cell differentiation, and cell motility. Furthermore, emerging evidence indicates that epigenetic regulations and noncoding RNAs may play important roles in breast cancer development and may contribute to the heterogeneity and metastatic aspects of breast cancer, especially for triple-negative breast cancer. This review provides a comprehensive survey of the molecular, cellular and genetic aspects of breast cancer.

Prognostic Significance of Progesterone Receptors Alone or in Association with Estrogen Receptors in Human Breast Cancer

Estrogen (ER) and progesterone (PgR) receptors were measured simultaneously in 1144 consecutive breast cancer patients to determine the distribution of patients according to receptor and menopausal status when receptor occurrence rates were considered. The prognostic signicance of PgR, either alone or in association with ER, was studied on 187 consecutive breast cancer patients treated only by radical mastectomy. All the cases, as regards axillary node status, were pathologically assessed as node negative. These patients did not receive any adjuvant treatment after mastectomy. At 36 months after mastectomy, the follow-up indicated that PgR- patients have a worse prognosis than PgR+ ones. This is evident when PgR alone is considered as a prognostic factor as well as when it is used to identify, within ER+ cases, those with a higher probability of relapse. In conclusion, it can be stated that although PgR status is an independent prognostic factor, it is useful to evaluate ER and PgR simultaneously for better patient management.

Estrogen and Progesterone Receptors in Breast Carcinoma and in Nonmalignant Breast Tissue

Since 1983 we have studied the relationship, in the same patient, between receptor status in breast carcinoma and in nonmalignant breast tissue. Fifty patients have been evaluated to date. The total unoccupied cytosol estrogen and progesterone receptors were determined by a dextran-coated charcoal method. In nonmalignant breast tissue we found a measurable receptor concentration above the sensitivity of the method in 62 % of cases for estrogen receptors and in 44 % of cases for progesterone receptors. No relationships were found between the receptor level of each tumor and that of the corresponding benign tissue. The data suggest that the levels of the receptors in the tumor and in the nonmalignant tissue are totally independent.

Digital image analysis in breast pathology-from image processing techniques to artificial intelligence

Breast cancer is the most common malignant disease in women worldwide. In recent decades, earlier diagnosis and better adjuvant therapy have substantially improved patient outcome. Diagnosis by histopathology has proven to be instrumental to guide breast cancer treatment, but new challenges have emerged as our increasing understanding of cancer over the years has revealed its complex nature. As patient demand for personalized breast cancer therapy grows, we face an urgent need for more precise biomarker assessment and more accurate histopathologic breast cancer diagnosis to make better therapy decisions. The digitization of pathology data has opened the door to faster, more reproducible, and more precise diagnoses through computerized image analysis. Software to assist diagnostic breast pathology through image processing techniques have been around for years. But recent breakthroughs in artificial intelligence (AI) promise to fundamentally change the way we detect and treat breast cancer in the near future. Machine learning, a subfield of AI that applies statistical methods to learn from data, has seen an explosion of interest in recent years because of its ability to recognize patterns in data with less need for human instruction. One technique in particular, known as deep learning, has produced groundbreaking results in many important problems including image classification and speech recognition. In this review, we will cover the use of AI and deep learning in diagnostic breast pathology, and other recent developments in digital image analysis.

"Triple negative breast cancer": Translational research and the (re)assembling of diseases in post-genomic medicine

The paper examines the debate about the nature and status of "Triple-negative breast cancer", a controversial biomedical entity whose existence illustrates a number of features of post-genomic translational research. The emergence of TNBC is intimately linked to the rise of molecular oncology, and, more generally, to the changing configuration of the life sciences at the turn of the new century. An unprecedented degree of integration of biological and clinical practices has led to the proliferation of bio-clinical entities emerging from translational research. These translations take place between platforms rather than between clinical and laboratory settings. The complexity and heterogeneity of TNBC, its epistemic and technical, biological and clinical dualities, result from its multiple instantiations via different platforms, and from the uneven distribution of biological materials, techniques, and objects across clinical research settings. The fact that TNBC comes in multiple forms, some of which seem to be incompatible or, at least, only partially overlapping, appears to be less a threat to the whole endeavor, than an aspect of an ongoing translational research project. Discussions of translational research that rest on a distinction between basic research and its applications fail to capture the dynamics of this new domain of activity, insofar as application is built-in from the very beginning in the bio-clinical entities that emerge from the translational research domain.

Intratumor Heterogeneity in Breast Cancer

Intratumor heterogeneity is the main obstacle to effective cancer treatment and personalized medicine. Both genetic and epigenetic sources of intratumor heterogeneity are well recognized and several technologies have been developed for their characterization. With the technological advances in recent years, investigators are now elucidating intratumor heterogeneity at the single cell level and in situ. However, translating the accumulated knowledge about intratumor heterogeneity to clinical practice has been slow. We are certain that better understanding of the composition and evolution of tumors during disease progression and treatment will improve cancer diagnosis and the design of therapies. Here we review some of the most important considerations related to intratumor heterogeneity. We discuss both genetic and epigenetic sources of intratumor heterogeneity and review experimental approaches that are commonly used to quantify it. We also discuss the impact of intratumor heterogeneity on cancer diagnosis and treatment and share our perspectives on the future of this field.

Cellular heterogeneity and molecular evolution in cancer

Intratumor heterogeneity represents a major obstacle to effective cancer treatment and personalized medicine. However, investigators are now elucidating intratumor heterogeneity at the single-cell level due to improvements in technologies. Better understanding of the composition of tumors, and monitoring changes in cell populations during disease progression and treatment, will improve cancer diagnosis and therapeutic design. Measurements of intratumor heterogeneity may also be used as biomarkers to predict the risk of progression and therapeutic resistance. We summarize important considerations related to intratumor heterogeneity during tumor evolution. We also discuss experimental approaches that are commonly used to infer intratumor heterogeneity and describe how these methodologies can be translated into clinical practice.

Ductal Carcinoma in Situ: Trends in Geographic, Temporal, and Demographic Patterns of Care and Survival

While long-term prognosis is excellent, treatment of ductal carcinoma in situ (DCIS) remains controversial and inconsistent. The purpose of this study was to track geographic and temporal patterns of care for women diagnosed with DCIS, and analyze subsequent cancer-specific risk of mortality. Subjects for this study were 41,245 women diagnosed with primary DCIS in the National Surveillance, Epidemiology, and End Results (SEER) program from 1973 through 2000. Variables analyzed included patient age, year of diagnosis, SEER site of residence at the time of diagnosis, treatment (surgery, radiation), race, age, and hormone (estrogen and progesterone) receptor status. The percentage of women diagnosed with DCIS out of the total number of women diagnosed with breast cancer increased steadily between 1973 and 2000, with the largest increase occurring around 1985. Breast conserving surgery (BCS) utilization increased over time for each SEER site to the current proportions, ranging from 49.5% in Utah to 76.9% in Connecticut. Younger women were significantly more likely to receive mastectomy and had significantly lower risk of death. Women receiving BCS who also had radiation therapy (RT) had a significantly lower risk of death, although those receiving mastectomy had the lowest risk of death. Black women and Asian/Pacific island women were significantly more likely to receive BCS, although black women were less likely to receive follow-up RT and had a significantly increased risk of death. Racial and age differences in the treatment of DCIS resulted in significantly disparate rates of survival, which should be considered in public health programming. Mastectomy utilization resulted in improved survival, although additional studies may elucidate the interaction of treatment with patient age.

Hormonal influences on cancer progression and prognosis

Cell differentiation, proliferation, apoptosis, and cell motility are induced and regulated by a host of growth factors, vitamins, and hormones. The mode of function of these modifiers of biological response, the signaling pathways that they activate, and the interacting pathways that can influence the biological outcome have been the focus of attention. Especially recognized and discussed in this review is the deregulation of their function, leading to abnormalities in cell proliferation, alteration of intercellular adhesive cohesion, remodeling of the extracellular matrix, and invasive behavior and metastatic deposition that are so characteristic of tumor development and progression, which strongly underscores the concept of molecular progression of cancer constructed on the basis of the relationship between genetic changes and the biological events associated with cancer progression. The molecular changes associated with hormone- and vitamin-driven responses and the deregulation of the expression and function of their target genes seem to correlate with specific biological events linked with cancer invasion and progression, and these findings could lead to the establishment of new markers of progression and to the development of new strategies for patient management. The scope of this work has been restricted by design and is dictated by the field of interest of the author's laboratory, but it is hoped that this field would be regarded adequately to reflect the wide genre of scientific interest in this field of human disease.

Immunohistochemical study of androgen receptors in breast carcinoma. Evidence of their frequent expression in lobular carcinoma

Androgens and androgen receptors (AR) are involved in the pathogenesis of breast cancer. Epidemiological studies have shown a significant association between the risk of breast cancer and androgens. However, the functional role and clinical value of AR expression in breast carcinoma have still not been clearly defined. The present study was set up to investigate the prevalence of ARs in a series of consecutive invasive breast carcinomas (IBCs) and to evaluate the patterns of AR phenotypes in a series of selected invasive lobular carcinomas (ILCs). Among the 250 consecutive IBCs (consisting of 212 ductal and 38 lobular neoplasms), AR immunoreactivity was observed in 151/250 (60.4%) cases, being expressed in 118/212 (56%) ductal and 33/38 (87%) lobular carcinomas (a statistically significant difference, chi2=11.82). AR expression was frequently associated with ER (65.2%, chi2=14.33) and PR positivity (66.9%, chi2=7.36). Most AR positive cases showed a low proliferative index (63.7%) and a low or intermediate histological grade (G1-G2, 63.9%). Among the 80 selected ILCs, AR expression was observed in 64/80 (80%) cases. Our results confirm that ARs are expressed in most breast cancers. Moreover, we demonstrated that AR positivity is particularly marked in lobular neoplasms. In addition, AR positive carcinomas are frequently characterized by a low or intermediate grade, a low proliferative index and ER and/or PR co-expression.

Influence of cellularity in human breast carcinoma

Ninty-three cases of both invasive ductal and lobular carcinoma were examined to clarify the relationship between the clinicopathological factors and cellularity (cell density) or total cancer cells number in carcinoma tissues. The cellularity showed significant correlation with tumor size and vascular invasion, but not with other clinicopathological factors (menopausal status, operation method, ER status, histological grade or type, lymph node stage) and prognosis. The total cancer cell number revealed a positive relationship with survival (overall survival) and disease-free interval (DFI) by univariate analysis, even though it did not show any positive correlation with other clinicopathological factors in this study. Moreover, it was not found to have any stronger impact than other previously reported prognostic factors such as tumor size, lymph node stage or tumor grade by multivariate analysis. From these evidences, we speculate that the cellularity correlates with expansion or invasion of tumor cells and the total number of cancer cells reflects the prognosis of the tumor-bearing host, although it does not play a major role in prediction.

Prediction of nodal spread of breast cancer by using artificial neural network-based analyses of S100A4, nm23 and steroid receptor expression

The expression of tumour promoter gene S100A4, metastasis suppressor gene nm23, oestrogen and progesterone receptors, and tumour grade and size have been investigated for their potential to predict breast cancer progression. The molecular and cellular data have been analysed using artificial neural networks to determine the potential of these markers to predict the presence of metastatic tumour in the regional lymph nodes. This study shows that tumour grade and size are poor predictors. The relative expression of S100A4 and nm23 genes is the single most effective predictor of nodal status. Inclusion of oestrogen- and progesterone-receptor status with tumour grade and size markers improves prediction; however, there may be some overlap between steroid receptors and molecular markers. This study also underscores the power of artificial neural network techniques to predict the potential of primary breast cancers to spread to axillary lymph nodes. This could aid the clinician in determining whether invasive procedures of axially node dissection can be obviated and whether conservative forms of treatment might be appropriate in the management of the patient.

Racial differences in treatment and survival from early-stage breast carcinoma

BACKGROUND

African-American women have a significantly worse prognosis from breast carcinoma compared with white women, even when the stage at diagnosis is equivalent. The purpose of this study was to analyze racial differences in the treatment (use of breast-conserving surgery and radiation therapy) of women with early-stage breast carcinoma and the resulting effects on survival rates.

METHODS

Subjects included 10,073 African-American and 123,127 white women diagnosed with Stage I, IIA, or IIB breast carcinoma in the National Cancer Institute's Surveillance, Epidemiology, and End Results program between 1988 and 1998. Comparisons were made by race with treatment, age, hormone receptor status, and stage at the time of diagnosis. Survival analyses were conducted to compare risk of death for African-American and white women while controlling for age, stage, and hormone receptor status.

RESULTS

Among women diagnosed with early-stage breast carcinoma who receive breast-conserving surgery, African-American women were significantly less likely to receive follow-up radiation therapy in every 10-year age group except in the older than 85 age group. Whether treatment was equivalent or suboptimal, survival for African-American women with early-stage breast carcinoma was significantly worse. However, when treatment was equivalent, the effects of racial differences on survival were significantly less compared with survival associated with suboptimal treatment.

CONCLUSIONS

Significant racial differences exist in the treatment of women with early-stage breast carcinoma. Public health efforts to eliminate suboptimal treatment would reduce, but not eliminate, racial disparity in survival.

Hormone receptors in breast cancer: racial differences in distribution and survival

The purpose of this study was to describe hormone receptor status and analyze the effect of receptors on survival from breast cancer. Comparisons were made between African-American and Caucasian racial categories. Breast cancer data from 1990 through 1997 collected by the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program were analyzed. Subjects were 993 Caucasian men, 12,303 African-American women, and 141,045 Caucasian women. The number of African-American men was too small to analyze separately (n = 93). In addition to analysis of estrogen and progesterone receptor status by sex and race, tumor and patient characteristics included age, stage at time of diagnosis, and tumor histology. The proportion of Caucasian men with hormone receptor positive tumors remained relatively high and stable for all ages. In women, the proportion of hormone receptor positive tumors increased with age, with African-American women having the highest proportion of hormone receptor negative tumors. Caucasian men had highest proportions of hormone receptor positive tumors in all histology and stage groups, while African-American women had lowest proportions of hormone receptor positive tumors in all stage and histologic categories. Survival for African-American women was significantly worse for each hormone receptor category. In multivariate analyses, race was a significant independent predictor of survival, but sex was not. Although reasons for differences in hormone receptor status by sex and race are unknown, several hypotheses are discussed with respect to differences in tumor histopathology and risk factors.

Association between estradiol, estrogen receptors, total lipids, triglycerides, and cholesterol in patients with benign and malignant breast tumors

This study addresses the correlation between the levels of estradiol (E2), total lipids, triglycerides, and cholesterol in serum and tissue samples of age-matched patients with benign (40 cases; 16 were premenopausal and 24 were postmenopausal) and malignant (50 cases; 17 were premenopausal and 33 were postmenopausal) breast tumors. Estradiol levels were determined in serum and cytosol, estrogen receptors (ER) were assayed in cytosol, and total lipids, triglycerides and cholesterol were determined in serum and membrane fractions of all benign and malignant breast disease patients. Serum E2 was significantly higher in malignant cases than benign ones (P<0.05) with a significant reduction (40%) in postmenopausal than premenopausal women. ER-positive tumors were significantly higher in postmenopausal women with malignant breast tumors than benign cases (P<0.05). Tissue levels of total lipids, triglycerides, and cholesterol were highly significantly increased in breast cancer women than women with benign breast diseases (P<0.05, P<0.005 and P<0.05 respectively) and they were also significantly correlated with estradiol levels. It could be concluded that the uptake of lipids from plasma by the tumor tissue is greatly correlated to estradiol and it may confirm the possible role of lipids as risk factor in breast cancer.

Variations in prognostic factors in primary breast cancer throughout the menstrual cycle

AIMS

We investigated whether menstrual cycle dependent variations in prognostic factors are detectable in malignant breast tissue.

METHODS

Since 1977 the Danish Breast Cancer Cooperative Group has collected population-based information about primary clinical data, treatment regimens and follow-up status on Danish women with breast cancer. Information about last menstrual periods prior to surgery was obtained from files recorded at the time of admission for primary surgery. Included in this study were 1060 patients self-reported to be regularly menstruating and with a menstrual period within 6 weeks of surgery and who were operated in a single-step procedure. None of the patients were current users of exogenous hormones at the time of surgery. Variations of prognostic factors throughout the menstrual cycle were evaluated.

RESULTS

Overall, no significant correlation between endogenous hormone fluctuations and oestrogen receptor (ER) status and progesterone receptor (PgR) status were found. Furthermore, we observed no cycle-dependent variation for mitotic index, lymph node involvement or tumour size.

CONCLUSIONS

The classical prognostic factors in breast cancer did not differ significantly throughout the menstrual cycle in the present study.

Immunolocalization of BRCA1 protein in normal breast tissue and sporadic invasive ductal carcinomas: a correlation with other biological parameters

AIM

BRCA1, a nuclear phosphoprotein, normally functions as a negative regulator of the cell cycle and may be an active inhibitor of neoplastic progression. Mutation of the BRCA1 gene has been demonstrated in 80% of familial breast cancer. Decreased mRNA levels or aberrant subcellular locations of BRCA1 have been identified in breast cancer lines and in sporadic cases of breast cancer tissues. The expression of BRCA1 in large series of variously differentiated breast carcinomas with correlation with other biological parameters has not been clarified.

METHODS AND RESULTS

The BRCA1 expression in normal breast tissue (n = 15) and in sporadic cases of invasive ductal carcinoma (n=108) was determined using immunohistochemistry. BRCA1 expression was correlated with other prognostic parameters including p53, c-erbB-2, bcl-2, oestrogen receptor (ER), histological grade, tumour size, axillary lymph node status and age. BRCA1 was exclusively (100%) localized in the nuclei of normal ductal and lobular epithelia. However, this nuclear expression pattern was variable in breast carcinoma (76.8%). Loss of nuclear BRCA1 expression (22 of 108 cases, 20.4%) correlated well with high histological grade (P<0.025) and bcl-2-negative tumours (P<0.05) and frequently in ER-negative tumours.

CONCLUSION

BRCA1 nuclear expression could be considered to represent the normal or physiological phenotype. Complete loss of BRCA1 nuclear expression in breast cancer and its correlation with other poor prognostic markers suggest that BRCA1 expression may play an important role in the pathogenesis and prognosis of sporadic breast carcinoma. Altered BRCA1 phenotype may therefore provide an additional prognostic parameter for breast cancer.

Prolactin: the forgotten hormone of human breast cancer

Prolactin (PRL) is both a mitogen and a differentiating agent in the mammary gland. It has been shown to be involved in mammary cancer development in rodents, but in human breast cancer, its role has long been overlooked. Three criteria are applied to demonstrate PRL's involvement in this disease: (1) PRL receptors are present in human breast cancer cells, (2) human breast cancer cells in culture respond to PRL as a mitogen, and (3) PRL is synthesized by human breast cancer cells and inhibition of the binding of PRL to its receptors inhibits cell growth.

New monoclonal antibodies to oestrogen and progesterone receptors effective for paraffin section immunohistochemistry

Assessment of oestrogen and progesterone receptors (ER and PgR) in breast cancer is widely used for the prediction of response to endocrine therapy and as a prognostic marker. Cytosolic assays have been replaced in many centres by immunochemical techniques, which have many advantages including applicability to small samples, simplicity, and cost-effectiveness. This study describes the generation and characterisation of two novel murine monoclonal antibodies recognizing ER and PgR, designated NCL-ER-6F11 and NCL-PGR respectively, which are effective in heat-treated formalin-fixed, paraffin-embedded tissue. The antibodies have been characterized by Western blotting and by immunohistochemistry on normal and pathological breast and other tissues. NCL-ER-6F11 has been shown to compare favourably with a currently available ER antibody. These antibodies may prove of value in the assessment of hormone receptor status in human breast cancer.

Steroid hormones and cancer: (III) observations from human subjects

Epidemiological evidence strongly suggests that steroid hormones are implicated in the risk of cancers of the breast, ovary and endometrium. However, it has proved difficult to implicate specific hormones or show that measurement of circulating hormones can identify women who will go on to develop malignant disease. There are, however, more convincing data that a proportion of established cancers are dependent upon steroid hormones for their continued growth and these underpin the use of endocrine manoeuvres in the treatment of these malignancies. Increased knowledge of the synthesis, release and mechanism of action of steroid hormones has led to the development of novel therapies for endocrine sensitive cancer and on-going research can reasonably be expected to identify tumour markers which can accurately predict hormone-dependency and provide better understanding of the mechanism by which response and resistance to therapy occur. The hope is that this knowledge will translate into more effective and rational endocrine treatment benefiting increased numbers of patients.

Tamoxifen inhibits nitrobenzylthioinosine-sensitive equilibrative uridine transport in human MCF-7 breast cancer cells

Tamoxifen inhibits the binding of [3H]nitrobenzylthioinosine ([3H]NBMPR) to human MCF-7 breast cancer cells with an IC50 of 8 microM. Tamoxifen at 30 microM changed the apparent Kd for [3H]NBMPR binding from 0.63 +/- 0.12 to 4.75 +/- 0.58 nM, with little effect on the Bmax (311000 +/- 76000 and 263000 +/- 46000 sites per cell for untreated and tamoxifen-treated cells respectively). Corresponding to this decrease in binding of [3H]NBMPR in the presence of tamoxifen was an inhibition of NBMPR-sensitive equilibrative transport of 50 microM [3H]uridine (IC50 7-10 microM). In the presence of 15 microM tamoxifen, the apparent K(m) for [3H]uridine transport was increased from 390 +/- 30 to 1500 +/- 250 microM, with no change in Vmax (12.0 +/- 0.1 and 11.3 +/- 4.3 microM/s for untreated and tamoxifen-treated cells respectively). The inhibitory effect of tamoxifen on NBMPR-sensitive equilibrative uridine transport was specific, as similar results were also observed in HL-60 leukaemia and EL4 lymphoma cells. Furthermore a similar concentration of tamoxifen had no effect on the NBMPR-insensitive equilibrative transport of uridine in MCF-7, HL-60 and Morris 7777 hepatoma cells, and on the Na(+)-dependent transport of uridine in murine splenocytes. In this paper we demonstrate that tamoxifen by itself might have some antiproliferative effects through inhibition of DNA synthesis by blocking the nucleoside salvage pathway.

8-hydroxydeoxyguanosine levels in DNA of human breast cancer are not significantly different from those of non-cancerous breast tissues by the HPLC-ECD method

8-Hydroxydeoxyguanosine (oh8dG) is a promutagenic DNA lesion produced by oxygen radicals, and a high level of 8-hydroxyguanine in breast cancers was previously demonstrated by the gas chromatography-mass-spectrometry method. To confirm the previous observation, the oh8dG levels of DNA of 22 breast cancers and corresponding adjacent non-cancerous breast tissues were analyzed by high performance liquid chromatography-electrochemical detector (HPLC-ECD) system, and the correlation of the oh8dG levels in breast cancer DNAs with clinical and immunohistochemical parameters was examined. However, the levels of oh8dG in DNA of breast cancers are not significantly different from those of corresponding non-cancerous breast tissues (P = 0.084) by the HPLC-ECD method. Furthermore, the oh8dG levels in breast cancers were not associated with p53 and erbB-2 immunoreactions, with expression of estrogen and progesterone receptors, and with clinical stage and histological grade. Thus, in contrast to the previous data, the present study using the HPLC-ECD method does not indicate an increase of oh8dG levels in breast cancers.

Modulatory influence of oral contraceptives on mammary growth pattern of normal and ovariectomised mice

The present study reports the modulatory influence of oral contraceptive formulations, Ovral (0.05 mg ethinylestradiol plus 0.5 mg norgestrel per pill), Noracycline (0.05 mg ethinylestradiol plus 0.1 mg lynestrenol per pill), Pearl (0.03 mg ethinylestradiol plus 0.30 mg norgestrel) and Centchroman (30 mg), on the growth and developmental pattern of murine mammary epithelium in normal as well as ovariectomised mice. Oral treatments of ovariectomised mice for 15 days with doses D1 (1/5th of a pill) and D2 (1/10th of a pill) of Ovral, Noracycline and Pearl enhanced the diameter of the terminal end buds (TEBS) and lateral buds (LBS) significantly. The increase in the diameters of TEBS and LBS on treatment with similar doses of Centchroman were not much significant. Hence, it may be concluded from the present study that the growth and development pattern of mammary epithelium can be modulated by treatment with oral contraceptives Oral, Noracycline, Pearl and Centchroman which is indicated by the increase in the diameters of TEBS and LBS.

Characteristics of a membrane-associated antilactogen binding site for tamoxifen

The antilactogen binding site (ALBS) is a membrane associated protein to which tamoxifen (TAM) and related non-steroidal antiestrogens, but not estrogen, bind. It is through this site that TAM inhibits lactogen binding to the prolactin (Prl) receptor and subsequent Prl induced growth and differentiation in target tissues. Binding of lactogens to the Prl receptor is inhibited by TAM or 4-hydroxy-TAM at 4 degrees C as well as room temperature, thus suggesting that the ALBS is not an enzyme. TAM acts by inhibiting the binding of lactogens to the receptor rather than promoting dissociation of the hormone-receptor complex. Lactogens bind to mammary gland membranes with an Kd of 4.3-8.2 x 10(-10) M. In the presence of 10(-7) M TAM the affinity decreased to a Kd of 0.8-1.6 x 10(-9) M. Binding of 3H-TAM to mammary gland membranes was effectively inhibited by an anti-Prl receptor antibody, thus suggesting a close relationship between the Prl receptor and the ALBS. Separate affinity purification of the ALBS and the Prl receptor resulted in peak fractions demonstrating specific binding activity for both TAM and lactogenic hormones. Re-isolation of the affinity purified Prl receptor on a TAM-Sepharose affinity resin again resulted in co-elution of both binding activities. The isolates from both affinity resins contained primarily a single band with an apparent molecular mass of 90 kDa. This band was precipitated with the anti-Prl receptor antibody and specifically bound the affinity label ring-3H-TAM aziridine.(ABSTRACT TRUNCATED AT 250 WORDS)

Histologic types and hormone receptors in breast cancer in men: a population-based study in 282 United States men

Histologic slides from 282 incident cases of breast cancer in men, that were identified in 10 population-based cancer registries in the United States, were reviewed by a single pathologist. Breast cancer more often presented in the noninvasive stage in men (10.8 percent of all cases) than would be expected among women. All noninvasive carcinomas were of the ductal type. Of invasive carcinomas, compared with women, men had smaller proportions of lobular and mucinous types and larger proportions of ductal and papillary types and Paget's disease. No case of tubular or medullary carcinoma was seen. The breast in men is composed only of ducts and normally contains no lobules, and the histologic types of breast carcinomas that predominate in men are likely of ductal origin. Estrogen and progesterone receptors were present in 86.7 percent and 76.3 percent of invasive carcinomas, respectively, which are higher proportions than would be expected among women. Also, unlike findings in women, receptor content was not associated with patient age at diagnosis.

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.

Steroid receptor status and the epidemiology of breast cancer

This case-control study examined risk factors for breast cancer according to tumor estrogen receptor (ER) status and progesterone receptor (PR) status. The data included 607 case patients and 1214 control subjects matched by age and residence. Of 528 case patients with steroid receptor information, 67% had ER-positive tumors and 55% had PR-positive tumors. Odds ratios for ER-positive and ER-negative breast cancer were similar with respect to menopausal status, age at menarche, history of cystic breast disease, and Quetelet Index. Family history of breast cancer was a stronger risk factor for ER-negative than for ER-positive breast cancer and the odds ratios for number of births were suggestive of a different effect. While ER and PR status were highly correlated, there were some differences in their associations with risk factors. Odds ratios for PR-positive and PR-negative breast cancer differed for number of births and were suggestive of differences with respect to menopausal status, Quetelet Index, and family history of breast cancer. These findings do not suggest different causal pathways for ER-positive and ER-negative breast cancer. However, they do indicate that PR status may play a role in the etiology of breast cancer.

Steroid receptors in breast cancer

Recent advances in steroid receptor structure and function now indicate that oestrogen binds to the oestrogen receptor (ER) molecule at a specific site, denoted region E. This allows binding of the oestrogen-ER complex to DNA via cysteine residues in region C of the ER molecule, which tetrahedrally co-ordinate zinc. This modulates transcription and stimulates cell growth. A number of newly discovered growth factors are also regulated by ER, as is the progesterone receptor. Steroid receptor concentrations in tissues can now be measured on smaller tissue samples using enzyme immunoassay or on cells obtained by fine needle aspiration using monoclonal antibody technology. The prognostic value of steroid receptor is limited, but still constitutes the best marker for predicting response to endocrine therapy. The role of steroid receptors in selecting patients for adjuvant therapy is discussed.

Transition of human breast cancer cells from an oestrogen responsive to unresponsive state

An in vitro model system is described for studying the problem of loss of steroid sensitivity in breast cancer cells. Growth of cloned oestrogen-sensitive human breast cancer cells in the long-term absence of steroid gives rise to a population of oestrogen-insensitive cells. In ZR-75-1 cells, the effect is clonal but occurs at high frequency suggesting a mechanism affecting a wide proportion of the cell population synchronously. This does not involve any reduction in oestrogen receptor number. Furthermore, there is no coordinated loss of oestrogen-sensitive molecular markers, showing that oestrogen receptors remain not only present but functional. These growth changes are not accompanied by any loss of growth inhibition by antioestrogen. Although steroid deprivation does not result in loss of oestrogen-sensitive markers, this does not hold true for other steroids. There was a reduction in progestin, androgen and glucocorticoid regulation on transfected LTRs. Loss of steroid-sensitive growth was accompanied by changes in response to exogenous growth factors and altered endogenous growth factor mRNA production. Steroid-deprived T-47-D cells acquire sensitivity to stimulation by TGF beta and have raised TGF beta 1 and TGF beta 2 mRNA levels. ZR-75-1 cells are growth inhibited by TGF beta and have reduced TGF beta 1 mRNA levels. In MCF-7 cells, increased IGFII mRNA, following transfection, can result in an increased basal cell growth rate in the absence of steroid. These findings are discussed in relation to possible autocrine mechanisms in the loss of steroid sensitivity of breast cancer cells.

Relationship between tumour aromatase activity, tumour characteristics and response to therapy

Aromatase activity has been measured in human breast cancers by incubating tumour minces with [7 alpha-3H]testosterone and characterizing purified oestradiol (E2) fractions by chemical derivative formation. Of 247 primary tumours, 178 showed evidence of oestrogen biosynthesis, levels varying between 0.5 and 12.5 fmol E2 produced/h/g tissue. These values were quantitatively small but at least comparable with those in other peripheral tissues. There was no correlation between presence or level of aromatase activity and the histopathology of the tumours although oestrogen biosynthesis was more likely to be present in more cellular tumours. Aromatase activity was also unrelated to age, menopausal status, lymph node status and T stage of the patient from which the tumour was derived. In a subgroup of patients presenting without clinical evidence of distant metastatic disease, no significant relation was detected between tumour aromatase and disease-free interval, but tumours without aromatase activity were associated with increased survival at 36 months after primary treatment. A statistically significant correlation was also detected between the presence of tumour aromatase and oestrogen receptors. Furthermore, in small subgroups of patients with "advanced" breast cancer tumour aromatase was related to response to aminoglutethimide but not tamoxifen therapy. Whilst these results do not conclusively define a role for local synthesis of oestrogen in the progression of breast cancer, this possibility still exists and further studies on tumour aromatase are warranted.

Endocrine treatment for breast cancers: biological rationale and current progress

Endocrine therapy is a major treatment modality for the systemic management of breast cancer. In comparison with alternatives such as chemotherapy, hormone manipulations have the advantage of lower toxicity but suffer from the disadvantages of producing responses in only 30-40% of patients with metastatic disease and seldom being curative. Nevertheless in recent years there have been significant advances in the endocrine treatment of breast cancer which have stemmed from a better understanding of the sources from which breast tumours may be supplied with hormones, the mechanism by which hormones regulate tumour proliferation and the more accurate identification of hormone sensitive tumours. As a result agents such as antioestrogens, aromatase inhibitors. LHRH agonists have largely superseded surgical and radiological ablation of endocrine organs. The major reduction in morbidity associated with these medical regimes means that they are much more acceptable to patients and may be used as adjuvants to local treatment of the breast in patients with "earlier" stages of the disease. At the same time patients can now be offered rational treatment selected on the basis of tumour biology rather than on more empirical criteria. The aims of this review are to provide details of the research which has led to this progress in endocrine treatment of breast cancer and to put into perspective the prospects for further advances.

The significance of steroid metabolism in human cancer

Epidemiological and clinical evidence suggests that steroid hormones are intimately involved in the natural history of many cancers, including those of the breast, endometrium and prostate. However, it has been difficult to demonstrate that progressive changes in tumour development are related to circulating levels of steroids. This may be because further metabolism of steroids occurs locally within the tumour and its adjacent host tissue. Using the breast as an example, data has been reviewed that such local metabolism may (a) markedly change the biological potency of steroid hormones and (b) be associated with the risk, presence, pathology, stage and hormone sensitivity of cancer. The implications of these findings are discussed including the need to identify factors which regulate steroid metabolism in peripheral tissue and tumours. In this way the potential to influence the microenvironment around and within tumour cells may be realized in favour of the patient.

A clinical evaluation of nuclear estrogen receptors combined with cytosolic estrogen and progesterone receptors in breast cancer

Breast cancer tissue from 95 women was simultaneously assayed for three receptors: cytosolic estrogen (CER), cytosolic progesterone (CPR), and nuclear estrogen (NER). The main objective was to determine whether the addition of NER assay to the currently accepted practice with only CER and CPR could improve the predictive capacity of receptors. Forty-two patients were studied for response to hormone therapy and 95 patients were studied for survival; the median follow-up period was 73 months (range, 8 to 300 months). The incidence of CER+, CPR+, and NER+ was 74%, 70%, and 52%, respectively. Each receptor appeared more frequently, although not significantly so, in higher age groups. Forty percent of tumors had all three receptors positive and 14% had all negative; the remaining tumors showed all possible combinations of receptors. Both the rate of response and survival curves among 70 patients with CER+ did not show any significant difference whether NER was positive or negative. Also, among 38 patients with CER+, CPR+, and NER+, there was no significant difference in the clinical outcome as compared to 17 patients with CER+, CPR+, and NER-. Among 25 patients with CER- the rare occurrence of NER+ in only three patients did not suggest any clinical implication. It is concluded, therefore, that on overall clinical grounds the current series does not support the addition of NER assay whenever data is available on both CER and CPR.

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

The oestrogen receptor content of 61 breast carcinomas was assessed by biochemical ligand binding assay and three immunohistochemical techniques--a frozen section method (Abbott ER-ICA) and on paraffin wax sections after fixation by two methods. The two fixatives used were Carson's buffered formalin and methacarn, and a DNAse pretreatment of sections was used. Overall agreement for the immunohistochemical methods with the ligand binding technique were 95%, 85%, and 86% for the frozen, formalin, and methacarn methods, respectively. A semiquantitative staining score was performed and all three methods gave significant correlations of staining scores with biochemical ligand binding values. The frozen section method was best (r = 0.88) with the fixed tissue methods yielding poorer correlation coefficients. Several factors affected staining, including the nature of the fixative and variable activity of DNAse. It is concluded that immunohistochemical assessment of oestrogen receptor content on fixed tissue provides acceptable qualitative information but that standardisation of protocols for tissue processing will be necessary for optimal utility and especially for quantitative assessments.

Season of tumour detection influences factors predicting survival of patients with breast cancer

The rate of initial detection of breast tumours varies during the year in a seasonal fashion, more tumours being discovered in late spring/early summer than at other times of the year. This phenomenon is particularly pronounced in young women (less than 50 years) with progesterone receptor positive tumours. The present study investigates whether season of tumour detection influences the predictive capacity of several recognised prognostic and risk factors in patients with breast cancer. Axillary nodal status, tumour progesterone receptor status, and season of tumour detection significantly influenced survival in both older (greater than 50 yrs) and younger (less than 50 yrs) patients. Parity, lactational history, body mass index, tumour oestrogen receptor status, and patient age also influenced survival, but these effects were significant only in age groups less than 50 or greater than 50 yrs. Season of detection of tumour did not effect the prognostic significance of axillary nodal status. However, the effect of oestrogen receptor status on survival was more significant in patients who detected their tumours in the spring/summer compared with winter (odds ratio 0.52 and 0.73 respectively). Negative progesterone receptor status was associated with significant poorer survival only in patients with tumours found in the winter. There was a significant survival disadvantage for nulliparous compared with parous women with breast cancer who were greater than or equal to 50 years at diagnosis, and for women who had never lactated compared with those who had lactated, but this disadvantage was restricted to those who found their tumours in the summer. An increased body mass index (greater than or equal to 28) was associated with decreased survival, but this was significant only for those detecting tumours in winter. The increased incidence of detection of breast cancer in spring/summer may reflect cyclic influences on tumour growth. Such influences may be hormonal in nature and may underlie the effect of season of tumour detection on the prognostic influence of lactation, parity, body mass index, and oestrogen and progesterone receptor status in patients with breast cancer.

Functional estrogen receptors as biochemical marker for the detection of hormone-dependent breast cancer

The translocatable receptors categorized as functional receptors were quantitated in a cross-incubation study of breast cancer nuclei with receptor-rich uterine cytosol. Data demonstrated that tumors that contained cytosolic estrogen receptor (ER) but had translocation defect might not be hormone dependent, whereas tumors with low ER but intact nuclear translocation step will respond to antiestrogen therapy. Cytosolic ER was estimated in 114 primary breast cancer tissues and ten metastatic axillary lymph nodes; 58% of postmenopausal and 54% of premenopausal breast cancer tissues were ER+ with a cutoff value of 10 fmoles and 3 fmoles/mg protein, respectively. Of tumors in the premenopausal and postmenopausal state, 62% and 57%, respectively, were positive for nuclear ER, with a cutoff value of 10 fmoles/100 micrograms DNA. This study suggested that evaluation of functional ER level would reduce the number of false-negative and false-positive tumors.

Expression of glutathione S-transferase B1, B2, Mu and Pi in breast cancers and their relationship to oestrogen receptor status

The concentrations of glutathione S-transferase (GST) B1 and B2 (Alpha), Pi and Mu have been measured by radioimmunoassay in cytosols from 28 oestrogen receptor (ER) rich an 30 ER-poor breast tumours. GST B1, B2 and Pi was detected in all 58 breast tumour cytosols whilst GST Mu was found in only 28. Of the GSTs, Pi was expressed most strongly in all cytosols and the concentration was significantly higher in ER-poor tumour cytosols than in ER-rich tumours (P less than 0.01). As with GST Pi, the highest levels of GST B1 and GST B2 were found in ER-poor tumour cytosols; the levels of GST B1 and GST B2 were positively correlated (r = 0.66, P less than 0.001). No quantitative or qualitative association was found between ER status and GST Mu which was expressed in 46% of ER-rich and 50% of ER-poor tumour cytosols. No relationship could be found between GST expression and age, menopausal status, lymph node involvement or tumour T stage in the subgroup of patients in whom this information was available. These data suggest that a common mechanism is responsible for GST induction in ER-poor tumours and that the nulled Mu phenotype has no increased susceptibility to developing breast cancer.

Immunological and physiological analysis of human breast cancer progesterone receptor heterogeneity, following KCl dissociation and size exclusion chromatography

Progesterone receptor (PR) levels were determined in 69 human breast cancer specimens by both radioligand assay (RLA) and enzyme immunoassay (EIA). These methods did not detect the same number of sites, and for each tumor there was a constant ratio between epitopes and PR-binding sites corresponding to 1/4, 2/4, ... 8/4. High performance size exclusion chromatography was performed to separate the various PR isoforms, and the ability of these isoforms to interact with the monoclonal antibodies was assessed. Determination of PR in the chromatographic fractions by EIA and RLA showed that the various isoforms isolated by chromatography presented variable quantities of steroid-binding sites and epitopes, thus confirming the differences observed in the cytosol assays. The dissociation of molybdate-stabilized PR by KCl and measurement by RLA and EIA of the isoforms obtained showed two different types of chromatographic patterns, particularly in the 8S polymeric form where the monoclonal antibodies appeared to detect mainly the heavier 8S fraction, which may correspond to the 8S-B form of the progesterone receptor. The monoclonal antibodies also detected an intermediate PR polymeric form (236 kDa) which was not always detected by the tritiated ligand. Our results suggest that breast cancer PR exhibit a marked molecular heterogeneity which may partially explain the differences in response to hormonal therapy, particularly for tumors with high receptor levels which nonetheless fail to respond to treatment.

The predictive value of progesterone receptor levels in endometrial cancer

Recent reports have suggested that the presence of progesterone receptor correlates with other well known predictors of a favorable outcome for endometrial cancer patients. To test this hypothesis, we reviewed the records of 154 patients who had undergone a hysterectomy for adenocarcinoma of the endometrium, and pelvic irradiation if poor prognostic factors were present. The 3 year disease-free survival for all clinical Stage I patients was 80%. Patients with progesterone receptor levels greater than or equal to 100 had a 3 year disease-free survival of 93% compared with only a 36% 3 year disease-free survival for patients with progesterone receptor less than 100 (p less than .0001, log rank test). To determine whether elevated progesterone receptor was an independent prognostic factor for disease-free survival in endometrial cancer, or just correlated with the other well-known predictors, bivariate and multivariate analyses were conducted. Our results indicate the progesterone receptor levels are the single most important prognostic indicator of 3 year disease-free survival in clinical Stage I endometrial cancer, with only cervical involvement and peritoneal cytology being significant prognostic variables after adjusting for progesterone receptor levels.

Relation between estrogen receptor concentration and clinical and histological factors: their relative prognostic importance after radical mastectomy for primary breast cancer

After modified radical mastectomy, 490 primary breast cancer patients were followed for a median of 75 months. Bloom grade was measured in 340 patients and ER status in 341. Follow-up of these patients has yielded the following results: (a) The value of traditional indices has been reaffirmed. (Cox's multivariate analysis identified, in order of decreasing importance, the number of invaded lymph nodes, the initial tumor size and the histological grade. Other variables were found to be of lesser importance and were correlated with the three main indices.) (b) The value of ER status disappeared after more than 3 years of follow-up. (c) ER positive patients fared better after recurrence. This was interpreted as being a consequence of their responsiveness to hormonal treatment.

Bowel function and breast cancer in US women

We studied bowel function in relation to 123 breast cancer cases among 7,702 women from the US NHANES I Epidemiologic Follow-up Study. Results suggest a slight increased risk of breast cancer for both decreased frequency of bowel movements (relative risk = 1.5, 95% confidence interval = 0.8, 2.7) and firm stool consistency (RR = 1.8, 95% CI = 1.0, 3.2.) These observations are consistent with an hypothesized association between constipation and increased risk of breast cancer.