The role of oestrogen and progesterone receptors in breast cancer - immunohistochemical evaluation of oestrogen and progesterone receptor expression in invasive breast cancer in women

Pre-clinical Evaluation of Karanjin Against DMBA-Induced Breast Cancer in Female Sprague-Dawley Rats Through Modulation of SMAR1 and CDP/CUx genes

PURPOSE

To investigate the chemoprotective potential of karanjin against 7,12-dimethylbenz(α)anthracene (DMBA)-induced breast cancer.

METHODOLOGY

Thirty-six female rats were utilized for the study. Breast cancer was induced through a subcutaneous injection of 35 mg/kg DMBA. The animals were allocated to six groups. Three groups were allocated for karanjin (50 mg/kg, 100 mg/kg, and 200 mg/kg), and received daily treatment for 20 weeks (including 2 weeks as pre-treatment). Doxorubicin (4 mg/kg) was administered to the standard control group twice a week for 20 weeks. The disease control (DC) and normal control (NC) groups received daily treatment with saline. After the treatment, oxidative stress parameters, biochemical parameters, and inflammatory parameters were estimated. CCAAT-displacement protein/cut homeobox (CUP/Cux) and scaffold/matrix attachment region binding protein 1 (SMAR1) expression levels were measured through gene expression analysis. Immunohistochemical (IHC) analysis was performed to estimate the expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2).

RESULTS

Tumor growth reduced significantly (P-value < 0.01) in karanjin-treated animals compared to the DC group. Karanjin significantly (P-value < 0.01) regulated the levels of oxidative stress parameters, biochemical parameters, and inflammatory parameters compared to the DC group. Karanjin treatment significantly (P-value < 0.001) regulated the expression levels of SMAR1 and CDP/Cux. A notable reduction in the IHC scores was observed for ER, PR, and HER2 expression in karanjin groups.

CONCLUSION

Karanjin demonstrated chemoprotective activity against DMBA-induced breast cancer in animals potentially through modulation of SMAR1 and CDP/Cux gene expression and reduction of ER, PR and HER2 expression levels.

Low progesterone receptor levels in high-grade DCIS correlate with HER2 upregulation and the presence of invasive components

Objective

In this study, we investigated pivotal molecular markers in human high-grade breast ductal carcinoma in situ (DCIS). Expression status of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth receptor 2 (HER2) was measured among various subtypes (Luminal (Lum) A, LumB HER2-, LumB HER2+, HER2-enriched and triple-negative).

Methods

In total, 357 DCIS cases were classified into respective subtypes, according to the 2013 St. Gallen guidelines. Each subtype was categorized into three subcategories: "Pure" (those without an invasive component), "W/invasive" (those with an invasive component), and "All" (the entire group of the given subtype). ER and PR expression were registered as intervals. Equivocal HER2 immunohistochemistry (IHC) cases (2+) were further investigated using dual-color in situ hybridization.

Results

The majority of patients (71%) were over the age of 50. We discovered no significant differences in the proportion of age between the "Pure" and "W/invasive" groups. There was no significant difference in ER/PR expression between "Pure" luminal subtypes of DCIS and "W/invasive" cases. We compared the HER2 IHC scores of "0", "1+", and "2+" among LumA and LumB HER2 subtypes and identified no statistically significant differences between "Pure" and "W/invasive" (p = 0.603). ER and PR expression ≥ 50% cutoff value was present in > 90% of all LumA cases. The incidences of cases with ER expression at cutoff values of < 10% and ≥ 50% in LumA were significantly different compared to other luminal subtypes (p < 0.0001). The proportion of cases with PR expression < 20% showed significant differences in the various luminal subtypes. In luminal B subtypes, low PR expression (< 20%) was significantly associated with both strong HER2 expression (3+) and the presence of an invasive component (p = 0.0001 and p = 0.0365, respectively).

Conclusions

ER and PR expression at ≥ 50% cutoff values were found in more than 90% of LumA cases. Samples with ER < 10% and ≥ 50% in LumA were significantly different compared to other luminal subtypes (p < 0.0001). Low PR expression in high-grade DCIS was strongly associated with HER2 overexpression (3+) and an invasive component (p = 0.0001 and p = 0.0365, respectively).

Expression Patterns of ER, PR, HER-2/neu and p53 in Association with Nottingham Tumour Grade in Breast Cancer Patients

Objectives

Recent molecular studies show that breast cancer (BC) is a heterogeneous disease, and several molecular changes may accumulate over time to influence treatment response. As a result, employing reliable molecular biomarkers to monitor these modifications may help deliver personalised treatment. However, this may be unrealistic in the resource-limited parts of the world. Thus, this study aimed to investigate the expression pattern of hormone receptors and p53 tumour suppressor using immunohistochemistry (IHC) in BC compared to the traditional tumour grade.

Methods

In total, 205 cases were investigated, and the Modified Bloom-Richardson score system was adopted in grading the tumours. The tissue sections of the cases were stained with specific primary antibodies at dilutions of 1:60 for oestrogen receptors (ER) and progesterone receptors (PR), 1:350 for the human epidermal growth factor (HER-2/neu) and 1:50 for p53.

Results

Invasive ductal carcinoma of no-specific type (n = 190, 92.7%) was predominant and grade II tumour (n = 146, 71.2%) was the most frequent. Hormone receptors ER (n = 127) and PR (n = 145) had 62.0% and 70.7% positive cases, respectively; 34.1% (n = 70) were positive for HER-2/neu, while 76.1% (n = 156) were positive for p53. Significant associations between Nottingham grade and expression patterns of ER (P <0.01), PR (P <0.001), HER-2/neu (P <0.001) and p53 (P = 0.001) were observed.

Conclusion

Nottingham grade had a high degree of concordance with the patterns of expression of hormone receptors, HER-2/neu and p53, suggesting that it may play an important role in connection with the predictive and prognostic biomarkers for BC.

Comparison of Mast Cell Density and Prognostic Factors in Invasive Breast Carcinoma: A Single-Centre Study in Malaysia

Background

Mast cells influence tumour growth, neo-angiogenesis and the propensity for metastasis by contributing to innate and adaptive immune responses in the tumour microenvironment. The number of mast cells has increased in various malignant tumours and their abundance has been associated with either a favourable or unfavourable prognosis. This study investigated the significant difference in stromal mast cell density among multiple prognostic factor groups in invasive breast carcinoma.

Methods

CD117 (c-KIT) antibodies were used to stain 160 formalin-fixed and paraffin-embedded invasive breast carcinoma tissues to demonstrate the presence of mast cells. Then the labelled mast cells were counted in 10 fields at 400× magnification and the mean value was used to represent the mast cell density.

Results

The demographic distribution revealed that most patients were 40 years old or older (92.5%) and of Malay ethnicity (66.3%). With regard to prognostic factors, the most prevalent subtype was invasive carcinoma of no special type (80.6%), followed by tumour grade 3 (41.3%), T2 tumour size (63.1%), N0 lymph node stage (51.3%), presence of lymphovascular invasion (59.4%), positive oestrogen (64.4%) and progesterone receptors (53.1%), and negative human epidermal growth factor receptor 2 (HER2) expression (75.0%). However, there was no significant difference in stromal mast cell density among the different demographic and prognostic factor groups in invasive breast carcinoma.

Conclusion

The findings from this study suggest that stromal mast cells do not play a significant role in preventing or promoting tumour growth in invasive breast carcinoma.

Proteomics-Based Identification of Dysregulated Proteins in Breast Cancer

Immunohistochemistry (IHC) is still widely used as a morphology-based assay for in situ analysis of target proteins as specific tumor antigens. However, as a very heterogeneous collection of neoplastic diseases, breast cancer (BC) requires an accurate identification and characterization of larger panels of candidate biomarkers, beyond ER, PR, and HER2 proteins, for diagnosis and personalized treatment, without the limited availability of antibodies that are required to identify specific proteins. Top-down, middle-down, and bottom-up mass spectrometry (MS)-based proteomics approaches complement traditional histopathological tissue analysis to examine expression, modification, and interaction of hundreds to thousands of proteins simultaneously. In this review, we discuss the proteomics-based identification of dysregulated proteins in BC that are essential for the following issues: discovery and validation of new biomarkers by analysis of solid and liquid/non-invasive biopsies, cell lines, organoids and xenograft models; identification of panels of biomarkers for early detection and accurate discrimination between cancer, benign and normal tissues; identification of subtype-specific and stage-specific protein expression profiles in BC grading and measurement of disease progression; characterization of new subtypes of BC; characterization and quantitation of post-translational modifications (PTMs) and aberrant protein-protein interactions (PPI) involved in tumor development; characterization of the global remodeling of BC tissue homeostasis, diagnosis and prognostic information; and deciphering of molecular functions, biological processes and mechanisms through which the dysregulated proteins cause tumor initiation, invasion, and treatment resistance.

Influence of the anti-oestrogens tamoxifen and letrozole on thyroid function in women with early and advanced breast cancer: A systematic review

INTRODUCTION

Breast cancer (BC) is a common type of cancer in women. Advances in therapy options have resulted in higher overall survival rates but side effects of cancer treatment are increasingly in the spotlight. The beneficial effects of anti-oestrogen therapy with tamoxifen and letrozole in the prevention of BC recurrence are well documented. While the most common side-effects of this therapy are well-defined, less is known about its effects on thyroid function. In women treated for early BC, an average of 1-5 kg weight gain has been observed after treatment with chemotherapy/anti-oestrogens. We aim to evaluate the current knowledge on the side effects of tamoxifen and letrozole treatments on thyroid function, followed by its potential influence on the observed weight gain.

METHODS

We searched PubMed and found 16 publications on thyroid function and tamoxifen treatment in pre- and post-menopausal women with early- and advanced BC, whereas five publications on letrozole treatment in post-menopausal women with advanced BC.

RESULTS

According to the current literature, there is an overall tendency towards a mild and transient thyroid dysfunction, that is, subclinical hypothyroidism in tamoxifen-treated patients. Only one publication reported further significant changes in thyroid hormones beyond one year of tamoxifen treatment. No significant changes in thyroid function have been observed among letrozole-treated patients.

CONCLUSION

Tamoxifen-treated patients can develop mild and transient thyroid dysfunction within the first 12 months, yet further significant changes in thyroid function beyond one year of tamoxifen treatment have been reported in a single study. There is no evidence of thyroid dysfunction in letrozole-treated patients. Current literature does not focus on subclinical hypothyroidism as a possible cause of weight gain in patients with BC. Subgrouping of BC patients and studies with a longer observation of thyroid hormones and weight changes during and after anti-oestrogen treatment are needed to further elucidate how anti-oestrogens affect thyroid function.

The Prognostic Value of Estrogen Receptor β Isoform With Correlation of Estrogen Receptor α Among Sudanese Breast Cancer Patients

Two estrogen receptor isoforms (ERα and ERβ) have been characterized with variable and sometimes contrasting responses to estrogens, partially explained by different receptor signaling pathways in estrogen-sensitive tissues. This is a retrospective, descriptive, cross-sectional study, aiming to evaluate the expression pattern of ERβ, employing immunohistochemical techniques using specific monoclonal antibody for ERβ, to correlate its expression with that of ERα in a Sudanese population. Two-hundred and fifty formalin-fixed paraffin-wax-embedded breast tissue blocks were used in this study. Of these, 200 were taken from breast cancer patients ascertained as study cases, and the remaining 50 were noninvolved surgical margin considered as normal breast tissue. Receptor expression was demonstrated using immunohistochemical techniques. The immune expression of ERβ was detected in 57.5% of breast cancers. It was differentially expressed in breast tissues encompassing normal, noninvasive, as well as invasive carcinoma (P = .02). There was no evidence of a significant relationship between ERβ and ERα expression. Among the ERα-negative tumor, 60.4% expressed ERβ. The expression of ERβ among this subgroup was significantly associated with good clinicopathological parameters such as negative Her2/neu, lower grade, and negative lymph node metastasis (P = .002). This study concludes that ERβ was commonly expressed among Sudanese patients with breast cancer, either co-expressed with ERα or expressed alone. In the ERα-negative subgroup, it was associated with better tumor outcomes suggesting ERβ should be included in the diagnostic protocol as an independent marker for favorable prognosis.

Zinc distribution within breast cancer tissue of different intrinsic subtypes

PURPOSE

To show feasibility of laser ablation inductively coupled mass spectrometry (LA-ICPMS) for analysis of zinc content and concentration in breast cancer tissue and to correlate this with validated prognostic and predictive markers, i.e. histological grading and expression of steroid receptors (estrogen receptor, ER; progesterone receptor, PR) and human epidermal growth-factor receptor 2 (Her2).

METHODS

28 samples of human invasive ductal breast cancer tissue were subclassified into groups of four different intrinsic subtypes according to the expression of ER, PR and Her2 by immunohistological staining and then analyzed for zinc content and distribution by LA-ICPMS applying a calibration technique based on spiked polyacrylamide gels. A correlation of zinc concentration with histological grading and molecular subtypes was analyzed.

RESULTS

Consistent with results of a pilot-study LA-ICPMS was feasible to show zinc accumulation in cancerous tissue, even more adjacent healthy stroma was with proportional increase of zinc. Zinc levels were most elevated in triple-positive (TPBC) and in triple-negative (TNB) breast cancers.

CONCLUSION

LA-ICPMS was feasible to confirm a connection between zinc and grade of malignancy; furthermore, focusing on a correlation of zinc and intrinsic breast cancer subtypes, LA-ICPMS depicted an upwards trend of zinc for "high-risk-cancers" with highest levels in Her2-positive and in triple-negative (TNBC) disease. The currently uncommon alliance of clinicians and analytical chemists in basic research is most promising to exploit the full potential of diagnostic accuracy in the efforts to solve the enigma of breast cancer initiation and course of disease.

Naturally-Occurring Canine Mammary Tumors as a Translational Model for Human Breast Cancer

Despite extensive research over many decades, human breast cancer remains a major worldwide health concern. Advances in pre-clinical and clinical research has led to significant improvements in recent years in how we manage breast cancer patients. Although survival rates of patients suffering from localized disease has improved significantly, the prognosis for patients diagnosed with metastatic disease remains poor with 5-year survival rates at only 25%. In vitro studies using immortalized cell lines and in vivo mouse models, typically using xenografted cell lines or patient derived material, are commonly used to study breast cancer. Although these techniques have undoubtedly increased our molecular understanding of breast cancer, these research models have significant limitations and have contributed to the high attrition rates seen in cancer drug discovery. It is estimated that only 3-6% of drugs that show promise in these pre-clinical models will reach clinical use. Models that can reproduce human breast cancer more accurately are needed if significant advances are to be achieved in improving cancer drug research, treatment outcomes, and prognosis. Canine mammary tumors are a naturally-occurring heterogenous group of cancers that have several features in common with human breast cancer. These similarities include etiology, signaling pathway activation and histological classification. In this review article we discuss the use of naturally-occurring canine mammary tumors as a translational animal model for human breast cancer research.

Outcomes of ovarian stimulation and fertility preservation in breast cancer patients with different hormonal receptor profiles

PURPOSE

To evaluate fertility preservation outcomes in breast cancer women with different hormonal receptor profiles before oncological treatment.

METHODS

The study population included women with a diagnosis of breast cancer who underwent fertility preservation from 2009 until 2018 at a university-affiliated tertiary hospital. Stimulation parameters and fertility preservation outcomes were compared among the following receptor-specific profile groups: (1) estrogen receptor positive (ER+) versus estrogen receptor negative (ER-), (2) triple-negative breast cancer (TNBC) versus estrogen and progesterone receptor positive (ER+/PR+), and (3) TNBC versus non-TNBC. Primary outcome was the total number of mature oocytes. Secondary outcomes included the number of retrieved oocytes, the peak estradiol level, and the number of follicles > 14 mm on the final oocyte maturation trigger day.

RESULTS

A total of 155 cycles were included in the final analysis. These were divided into the exposure groups of ER+ (n = 97), ER- (n = 58), ER+/PR+ (n = 85), TNBC (n = 57), and non-TNBC (n = 98). Cycle outcomes revealed similar number of retrieved oocytes and follicles > 14 mm on the trigger day. Women with TNBC had significantly lower number of mature oocytes compared with those with ER + PR+ (7 (5-11) versus 9 (7-15); p = 0.02) and non-TNBC (7 (5-11) versus 9 (7-16); p = 0.01) status. Triple-negative breast cancer profile was associated with a significant reduction in the chance of developing over 10 mature oocytes (OR 0.41; 95% CI 0.19-0.92).

CONCLUSION

Among the different hormonal receptor profiles in breast cancer, the TNBC subtype has a negative effect on fertility preservation outcomes.

Differences in race, molecular and tumor characteristics among women diagnosed with invasive ductal and lobular breast carcinomas

BACKGROUND

The dominant invasive breast cancer histologic subtype, ductal carcinoma, shows intrinsic subtype diversity. However, lobular breast cancers are predominantly Luminal A. Both histologic subtypes show distinct relationships with patient and tumor characteristics, but it is unclear if these associations remain after accounting for intrinsic subtype.

METHODS

Generalized linear models were used to estimate relative frequency differences (RFDs) and 95% confidence intervals (95% CIs) for the associations between age, race, tumor characteristics, immunohistochemistry (IHC) and RNA-based intrinsic subtype, TP53 status, and histologic subtype in the Carolina Breast Cancer Study (CBCS, n = 3,182) and The Cancer Genome Atlas (TCGA, n = 808).

RESULTS

Relative to ductal tumors, lobular tumors were significantly more likely to be Luminal A [CBCS RNA RFD: 44.9%, 95% CI (39.6, 50.1); TCGA: RFD: 50.5%, 95% CI (43.9, 57.1)], were less frequent among young (≤ 50 years) and black women, were larger in size, low grade, less frequently had TP53 pathway defects, and were diagnosed at later stages. These associations persisted among Luminal A tumors (n = 242).

CONCLUSIONS

While histology is strongly associated with molecular characteristics, histologic associations with age, race, size, grade, and stage persisted after restricting to Luminal A subtype. Histology may continue to be clinically relevant among Luminal A breast cancers.