Characterization of estrogen receptor–negative/progesterone receptor–positive breast cancer

Clinical Outcomes and Intrinsic Subtypes of Breast Cancer Patients with Single Hormone Receptor-positive Receiving Neoadjuvant Chemotherapy

BACKGROUND

Extensive studies have highlighted the significance of estrogen receptor (ER) and progesterone receptor (PR) in breast cancer (BRCA). However, our understanding of patients with single hormone receptor (HR)-positive (sHR+) BRCA remains limited. This lack of understanding poses challenges in predicting prognosis and selecting appropriate treatments.

PATIENTS AND METHODS

We collected data from a total of 825 human epidermal growth factor receptor 2 negative (HER2-) BRCA patients who underwent neoadjuvant chemotherapy (NAC) in two distinct cohorts. Four subgroups were created within each cohort based on their HR expression: ER+/PR+, ER+/PR-, ER-/PR+, and ER-/PR-. We conducted comparative analyses to assess clinicopathological characteristics, chemotherapy responsiveness, clinical outcomes, and intrinsic subtyping among these subgroups.

RESULTS

ER+/PR- constituted 11.1% and 14.9% of samples in two cohorts, respectively, whereas ER-/PR+ comprised 8.3% and 3.7%. Higher histologic grades were more common in the ER-/PR+ group as compared to the ER+/PR+ subgroup (P = .0075 in cohort 1; P = .026 in cohort 2). Additionally, after multivariable analysis, ER-/PR+ were more likely to achieve pathological complete response (pCR) (cohort 1: OR =6.67; 95%CI, 2.63-16.94; P < .001; cohort 2: OR =3.70; 95%CI, 1.08-11.84; P = .030;). Between ER+/PR- and ER+/PR+, the distant recurrence-free survival (DRFS) was comparable. The survival outcomes in the ER-/PR+ subgroup present a partial inconsistency between the 2 cohorts. Furthermore, the ER-/PR+ subgroup exhibited a higher incidence of the basal-like subtype, while the ER+/PR- subgroup had a higher proportion of luminal-like subtypes.

CONCLUSION

This study highlighted the distinct clinical and genetic characteristics of sHR+ BRCA, emphasizing the potential need for optimized treatment strategies.

Estrogen receptor-negative/progesterone receptor-positive breast cancer has distinct characteristics and pathologic complete response rate after neoadjuvant chemotherapy

PURPOSE

The status of hormone receptors (HR) is an independent factor affecting survival and chemotherapy sensitivity in breast cancer (BC) patients, with estrogen receptor (ER) and progesterone receptor (PR) having the most significant effects. The ER-/PR + phenotype has been controversial in BC, and experts will face many challenges in determining treatment strategies. Herein, we systematically analyzed the clinicopathological characteristics of the ER-/PR + phenotype in BC patients and the response to chemotherapy.

PATIENTS AND METHODS

We included two cohorts. The first cohort counted the relationship between clinicopathologic data and survival outcomes for 72,666 female patients in the Surveillance, Epidemiology, and End Results (SEER) database. The second cohort analyzed the relationship between clinicopathological data and pathologic complete response (pCR) rate in 879 patients at the Harbin Medical University Cancer Hospital. The classification data were compared by the chi-square test and Fister's exact test of the Logistic regression model, and predictor variables with P < 0.05 in the univariate analysis were included in the multivariate regression analysis. The Kaplan-Meier method evaluated breast cancer-specific survival (BCSS) and overall survival (OS) to investigate the relationship between different HR typing and survival and pCR.

RESULTS

In the two cohorts, 704 (0.9%) and 11 (1.3%) patients had the ER-/PR + phenotype, respectively. The clinicopathologic features of patients with the ER-/PR + phenotype are more similar to those of the ER-/PR- phenotype. The ER-/PR + phenotype is more common in younger and premenopausal women, and most ER-/PR + phenotypes exhibit higher histological grades. Survival analysis showed that there were significant differences in OS and BCSS among patients with different HR states (P < 0.001). The survival results of patients with the ER + /PR + phenotype were the best. The prognosis of the ER-/PR + phenotype was similar to that of the ER-/PR- phenotype. On the other hand, we found that HR status was also an independent predictor of post-NAC pCR rate in BC patients. The ER + /PR- and ER-/PR- phenotypes were more sensitive to chemotherapy than the ER + /PR + phenotypes.

CONCLUSION

HR status is the main factor affecting BC's survival outcome and pCR rate. Patients with the ER-/PR + phenotype possess more aggressive biological factors and can benefit significantly from chemotherapy. We need to pay more attention to this group and achieve individualized treatment, which will help us treat BC better and provide new targets and blueprints for our clinical treatment.

Hormone receptors in breast cancer: An update on the uncommon subtypes

Breast cancer is the most common cancer affecting women and is the second leading cause of cancer death among US women. Estrogen receptor (ER) signaling plays a crucial role in mammary gland development and carcinogenesis. Near 80 % of invasive breast cancers are ER-positive (ER+). Endocrine therapies targeting ER have significantly improved the prognostic outcomes in the patients with ER+ breast cancer, and the therapeutic effects are strongly correlated with the levels of the ER expression in tumor cells. Despite being an ER-dependent gene product, PR is not always overexpressed in ER+ tumors, and a small subset of breast cancers demonstrates an ER+/PR- phenotype, and a rare ER-/PR+ subtype also exists. There have been controversies on the biology of these tumor types and the predictive and prognostic power of PR status. Compelling data have shown the distinct biologic characteristics of ER+/PR- and ER-/PR+ tumors. Despite that ER-low breast cancers demonstrate more similarity to ER- tumors, at least a subset of ER-low carcinomas may have a functional ER signaling. Thus, adequate PR expression is essential as its absence indicates impaired ER pathway. Assessment of PR status may not only distinguish the ER+/PR- subset from the ER+ and ER-low tumors, but also differentiate the ER-/PR+ phenotype from the ER- carcinomas, both with therapeutic implications. This article was aimed to provide an up-to-date review focusing on the clinicopathologic characteristics of uncommon subtypes of breast cancer, including ER+/PR-, ER-/PR+, and ER-low breast cancers.

Assessment of Predictive Biomarkers in Breast Cancer: Challenges and Updates

The management of patients with breast cancer (BC) relies on the assessment of a defined set of well-established prognostic and predictive markers. Despite overlap, prognostic markers are used to assess the risk of recurrence and the likely benefit of systemic therapy, whereas predictive markers are used to determine the type of systemic therapy to be offered to an individual patient. In this review, we provide an update and present some challenges in the assessment of the main BC-specific molecular predictive markers, namely hormone receptors (oestrogen receptor [ER] and progesterone receptor [PR]), human epidermal growth factor receptor 2 (HER2), and KI67. As the main platform for assessing these markers in BC is immunohistochemistry (IHC), we address the cut-off values used to define positivity, the ER-low subgroup, the existence and significance of the ER-/PR+ phenotype, the use of PR in routine practice, and the role of hormone receptors in ductal carcinoma in situ. We discuss the newly introduced HER2-low class of BC and the clinical/biological difference between different HER2 groups (e.g., HER2 IHC score 3+ BCs vs. those with a HER2 IHC score 2+ with HER2 gene amplification). The review concludes with an update on the applications of KI67 assessment in BC and observations on the role of immune checkpoint identification in BC.

A simplified breast cancer prognostic score: comparison with the AJCC clinical prognostic staging system

There have been many breast cancer prognostic models proposed in the last few decades, varying in their methods of development and validation, predictors, outcomes, and patients included. Most models were developed to assess prognostic outcomes for early breast cancers. In this study, we established a simplified prognostic score to predict survival outcomes in all breast cancer patients. A total of 36,152 breast cancer patients diagnosed between 2010 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database were used as the training dataset. Multivariate analyses were performed to identify independent factors for disease-specific survival (DSS). A prognostic score was calculated by summing the point values based on the magnitude of the hazard ratio for all independent factors. The authors institutional cohort (n = 4982) was used as the validation dataset. The prognostic score model consisting of histologic grade, ER, PR, HER2, and TNM status demonstrated a similar predictive power when compared to the revised 8th AJCC Clinical Prognostic Staging system in both training and validation datasets, whereas the addition of age and race did not facilitate stratification of prognostic groups. Pairwise comparison of hazard ratios showed a significant difference in all categories when compared to their proximate groups in both prognostic schemes in the SEER database, while the prognostic score model demonstrated a slightly better discriminating power in the validation dataset. Thus, the proposed prognostic score showed at least a comparable predicting power for survival outcomes in breast cancer patients receiving standard-of-care treatment when compared to the AJCC Clinical Prognostic Stage. This prognostic model provides a convenient and alternative modality in clinical practice thus warranting further validation using larger cohorts with longer follow-up.

Is oestrogen receptor-negative/progesterone receptor-positive (ER-/PR+) a real pathological entity?

Background

The existence of oestrogen receptor-negative (ER−)/progesterone receptor-positive (PR+) breast cancer continues to be an area of controversy amongst oncologists and pathologists.

Methods

To re-evaluate breast cancers originally classified as ER−/PR+ via Oncotype DX® assay and compare molecular phenotype with Recurrence Score® (RS) result, clinicopathologic features and clinical outcomes were retrospectively obtained from electronic health records between January 1998 and June 2005. Archived formalin-fixed, paraffin-embedded (FFPE) tumour specimens were tested for the expression of ER, PR and human-epidermal-growth-factor-2. The number of positive ER−/PR+ samples confirmed by transcriptional analysis was the primary outcome of interest with event-free and overall survival as secondary outcomes. Biopsies from 26 patients underwent Oncotype DX testing and analysis.

Results

Approximately 60% were middle-aged (40–50 years old) women, and 84.6% had invasive ductal carcinoma. Based on the Oncotype DX assay, approximately 65% (N = 17) had ER+/PR+ status; 23% (N = 6) had ER−/PR− status; and 12% had a single hormone positive receptor (1 ER–/PR+, 2 ER+/PR–) status. Almost one-quarter of patients were stratified into the low-RS (<18) or intermediate-RS (18–30) results, and half of the patients had a high-RS (>30) result.

Conclusion

Our findings suggest the ER−/PR+ subtype is not a reproducible entity and emphasises the value of retesting this subtype via molecular methods for appropriate treatment selection and patient outcomes. Multigene assay analysis may serve as a second-line or confirming tool for clinical determination of ER/PR phenotype in breast cancer patients for targeted therapies.

The Prognosis of Single Hormone Receptor-Positive Breast Cancer Stratified by HER2 Status

Single estrogen receptor (ER)+ and progesterone receptor (PR)+ tumors account for about10% of all breast cancers. However, the prognosis of these single hormone receptor-positive (HR+) tumor remains unclear. We aimed to investigate the characteristics of single HR+ breast tumors according to HER2 status in order to improve the treatment of patients with single HR+. Patients from the SEER program (2010-2016) were divided into ER+PR-, ER-PR+, ER+PR+ and ER-PR- molecular subtypes stratified by HER2 status. Overall survival (OS) and breast cancer-specific survival (BCSS) were compared by Kaplan–Meier curves after propensity score matching (PSM). A total of 203,406 patients were enrolled. Single ER+ and PR+ tumors account for 11.9% of the total population. For HER2- subtype, patients with ER+PR- (n = 16906 pairs) and ER-PR+ (n = 1395 pairs) had worse prognoses than those with ER+PR+ with hazard ratio (HR) and 95% confidence interval (CI) of 1.52 (1.41-1.64) and 2.25 (1.76-2.88) for OS; and 1.94 (1.76-2.14) and 2.57 (1.94-3.40) for BCSS, respectively; ER+PR- showed a better prognosis than ER-PR+ (n = 1394 pairs) and ER-PR- (n = 9626 pairs) with HR (95% CI) of 1.32 (1.06-1.65) and 1.44 (1.33-1.55) for OS, and 1.32 (1.03-1.69) and 1.46 (1.34-1.60) for BCSS, respectively; ER-PR+ had a similar prognosis relative to ER-PR- (n = 1395 pairs) after PSM. For HER2+ subtype, patients with ER-PR+, ER+PR-, and ER-PR- had similar OS and BCSS; ER+PR+ showed a similar prognosis compare with ER-PR+ (n = 535 pairs), but had better OS and BCSS than ER+PR- (n = 5376 pairs) and ER-PR- (n = 8143 pairs) after PSM. In addition, ER+PR+HER2+ showed similar OS and better BCSS compared with ER+PR+HER2- after PSM. In conclusion, single PR+ patients experienced poorer prognoses than single ER+ patients, and may be treated as ER-PR- patients in HER2- subtype. In HER2+ patients, both single ER+ and single PR+ cases showed similar prognoses compared with ER-PR- cases, and may be treated as ER-PR- patients.

ER-/PR+ breast cancer: A distinct entity, which is morphologically and molecularly close to triple-negative breast cancer

Determining the status of steroid hormone receptors [oestrogen (ER) and progesterone receptors (PR)] is a crucial part of the breast cancer workup. Thereby, breast cancers can be classified into four subtypes. However, the existence of ER-/PR+ tumours, often reported to be ill-classified due to technical errors, remains controversial. In order to address this controversy, we reviewed the hormone receptor status of 49 breast tumours previously classified as ER-/PR+ by immunohistochemistry, and compared clinical, pathological and molecular characteristics of confirmed ER-/PR+ tumours with those of ER+ and triple-negative tumours. We unequivocally confirmed the ER-/PR+ status in 27 of 49 tumours (0.3% of all breast cancers diagnosed in our institution between 2000 and 2014). We found that ER-/PR+ were morphologically and histologically similar to triple-negative tumours, but very distinct from ER+ tumours, with more aggressive phenotypes and more frequent basal marker expression than the latter. On the molecular level, RNA sequencing revealed different gene expression profiles between the three groups. Of particular interest, several genes controlled by the suppressor of zest 12 (SUZ12) were upregulated in ER-/PR+ tumours. Overall, our results confirm that ER-/PR+ breast cancers are an extremely rare but 'real' tumour subtype that requires careful diagnosis and has distinct features warranting different responsiveness to therapies and different clinical outcomes. Studies on larger cohorts are needed to further characterise these tumours. The likely involvement of SUZ12 in their biology is an interesting finding which may - in a long run - give rise to the development of new therapeutic alternatives.

Characterization of estrogen receptor-low-positive breast cancer

PURPOSE

The biology of breast cancer with a low expression level (1-10%) of estrogen receptor (ER) remains a matter of confusion. The recent American Society of Oncology/College of American Pathologist Guidelines have recommended reporting such tumors as a new "ER-low-positive" category with a recommended comment to emphasize the possible overall benefit of endocrine therapies in these patients. The aim of the study was to analyze the clinicopathologic features and clinical outcomes of ER-low-positive breast cancers.

METHODS

We characterized the clinicopathologic features and survival outcomes of ER-low-positive breast cancers in our 4179 patients diagnosed from 1998 to 2018.

RESULTS

The ER-positive, ER-low-positive, and ER-negative cases in our cohort were 2982 (71.4%), 97 (2.3%), and 1100 (26.3%), respectively. ER-low-positive tumors showed similar clinicopathologic characteristics yet significantly superior prognosis when compared to ER-negative tumors, while demonstrated largely overlapping survival outcomes with ER-positive tumors in the entire cohort. In the subcohort of tumors with a PR-positive phenotype, the prognosis of ER-low-positive tumors was intermediate between that of the ER-positive and ER-negative groups. ER-low-positive/PR-positive tumors had a significantly worse prognosis than ER-positive tumors, and a trend toward favorable survival outcomes when compared to ER-negative tumors, although no significant difference was identified for the latter. In contrast, the ER-positive and ER-low-positive groups showed similar survival outcomes in the subset of tumors with a PR-negative status, both being significantly better than ER-negative tumors.

CONCLUSIONS

PR status as a surrogate marker of functional ER signaling provides critical information in this regard. These findings suggest that while ER-low-positive tumors are themselves heterogeneous, they often respond to endocrine treatment. Analysis of molecular signatures and standardization of therapeutic strategies are important to understand the biology of ER-low-positive tumors and to enable optimal treatment in the pursuit of individualized medicine.

Receptor conversion in metastatic breast cancer: analysis of 390 cases from a single institution

Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2) status provide clinical utility in guiding therapeutic decision-making in metastatic breast cancer (BC). Increasing data have shown substantial differences between the receptor profiles of primary BCs and their paired metastases. In this study, we provide a large single center cohort to assess the frequency of receptor conversion in metastatic BC. The overall discordant rates were 18.3%, 40.3%, and 13.7% for ER, PR, and HER2, respectively. The discordance was significantly higher for PR when compared with ER and HER2. The conversion occurred significantly as a switch from positive to negative receptor status when compared with that from negative to positive for all three receptors. Semiquantitative analyses revealed a significantly decreased expression of both ER (25%) and PR (57%) in the metastases. There was a higher rate of PR discordance in bone metastases when comparing to other common organs of relapse. Furthermore, in the subset of patients with a single primary and multiple distant metastases, the discordant rates among the distant sites were 27.5%, 39.4%, and 14.3% for ER, PR, and HER2, respectively. A positive ER status, be it in primary or metastatic BC, was associated with a prolonged metastasis-free survival when compared with ER-negative primary tumors without conversion. Furthermore, a positive ER status in metastatic BC regardless of primary was associated with a superior overall survival when compared with an ER-negative tumor without conversion. Thus, receptor conversion is a frequent event in the course of BC progression, and can also be seen between different metastatic sites. Moreover, some conversions are of prognostic significance. The findings may reflect tumor heterogeneity, sampling or treatment effect, but may also indicate alteration in tumor biology. Repeat biomarker testing is warranted in making appropriate treatment plans in the pursuit of precision medicine.

Negative estrogen receptors and positive progesterone receptors breast cancers

CONTEXT

Hormone receptors (estrogen receptor ER and progesterone receptor PR) are prognostic and predictive factors of outcome for invasive breast cancer. Some tumors only express one of these hormone receptors (ER or PR). ER negative/PR positive breast cancer is a rare subtype (1-4 %) and its existence still controversial. The aim of this study was to evaluate characteristics of this group of tumors.

METHODS

We collected data of all consecutive patients managed in our institution for invasive breast cancer between the 1st January 2007 and 31 December 2013. The aim of the study was to compare data of patients with ER-/PR+tumors with the three other subgroups.

RESULTS

Of the 2071 patients included during the study period, 1.2 % were ER-/PR+. These patients were younger than those with the two ER+groups (p<0.0001). The ER-/PR+tumors differed from the ER+groups for several histological prognostic factors: greater histological size (p=0.0004), higher histological grade, more HER2 overexpression/amplification, more association with ductal carcinoma in situ, more lymphovascular invasion, more nodal metastasis (p<0.0001). Chemotherapy was more often used as an adjuvant treatment in addition of endocrine therapy. Survival was equivalent for patients with ER-/PR+tumors and ER+tumors and significantly higher than patients with ER-/PR- tumors (p<0.0001).

CONCLUSION

Women with ER-/PR+breast cancer have worse prognostic factors than women with ER+cancers but have better overall survival than women with ER-/PR- tumors. We may think that the more frequent association of chemotherapy and endocrine therapy is responsible for this better outcome.

Single Hormone Receptor-Positive Breast Cancers Have Distinct Characteristics and Survival

BACKGROUND

Estrogen receptor (ER) and progesterone receptor (PR) status is pivotal to determining the prognosis and treatment of human epidermal growth factor 2 (HER2) receptor-negative invasive breast cancer. Frequently ER-positive (ER+) and/or PR-positive (PR+) cancers are labeled nonspecifically as "hormone receptor-positive" although only one is positive. This study aimed to evaluate and characterize the ER+PR- and ER-PR+ breast cancer phenotypes in reference to ER+PR+ cancers.

METHODS

A retrospective cohort study of female patients with HER2-negative (HER2-) invasive breast cancer diagnosed in 2010-2015 was performed using the National Cancer Database. Cases were grouped into ER+PR+, ER-PR+, ER+PR-, and ER-PR- phenotypes to determine differences in patient demographics, tumor characteristics, and overall survival.

RESULTS

Of 823,969 cases, 619,050 (75.1%) were ER+PR+, 79,777 (9.7%) were ER+PR-, 7006 (0.9%) were ER-PR+, and 118,136 (14.3%) were ER-PR-. Compared with the ER+PR+ group, the ER+PR- and ER-PR+ groups were more likely to be high-grade cancer (16.0% vs. 34.2% and 80.0%, respectively; p < 0.001), to have lymphovascular invasion (17.9% vs. 19.6% and 23.0%; p < 0.001), to be node-positive (13.5% vs. 19.7% and 26.3%; p < 0.001), to be stage 4 cancer (3.6% vs. 5.9% and 6.7%; p < 0.001), to have a higher multigene assay score (mean, 16.0 vs. 27.8 and 38.1; p < 0.001), and to have a worse survival (90.6% vs. 83.8% and 78.1%; p < 0.001).

CONCLUSION

Single hormone receptor-positive breast cancer subtypes (ER+PR- and ER-PR+) are more likely to have unfavorable characteristics and worse survival than the ER+PR+ subtype, with the ER-PR+ subtype having outcomes similar to those for ER-PR- cancers. The single hormone receptor-positive subtypes, representing 10% of HER2- cancers, should be considered clinically distinct from ER+PR+ disease.

Clinical Features and Survival of Single Hormone Receptor-Positive Breast Cancer: A Population-Based Study of 531,605 Patients

PURPOSE

To investigate the prognosis of single hormone receptor-positive (HR⁺) breast cancer (estrogen receptor [ER] positive and progesterone receptor [PR] negative, and ER^-PR⁺) compared to double HR⁺ (ER⁺PR⁺) and double HR^- (ER^-PR^-) tumors.

METHODS

We included 531,605 cases of invasive breast cancer between 1990 and 2012 from the US Surveillance, Epidemiology, and End Results (SEER) database for study and classified cases into 4 phenotypes according to expression of ER and PR: ER⁺PR⁺, ER⁺PR^-, ER^-PR⁺, and ER^-PR^-.

RESULTS

Overall, 66,091 ER⁺PR^- tumors and 9320 ER^-PR⁺ tumors were identified. The clinical characteristics of the ER⁺PR^- group were similar to those of the double HR⁺ group, while those of the ER^-PR⁺ and double HR^- groups were similar. Overall survival of patients with single HR⁺ tumors was intermediate between that of double HR⁺ and double HR^- tumors. However, we observed no differences in disease-specific survival between ER^-PR⁺ and ER^-PR^- patients. In multivariate analysis, outcomes were similar. Relative to the double HR⁺ patient group, risk of death in the ER⁺PR^- group was higher (hazard ratio, 1.422, 95% confidence interval, 1.394-1.452). However, risk of death was comparable between ER^-PR⁺ and ER^-PR^- patients (hazard ratio, 1.03; 95% confidence interval, 0.98-1.08). Multivariate Cox proportional analysis showed that survival times of patients in the younger age bracket (< 60 years), those positive for human epidermal growth factor receptor 2 (HER2), and patients with tumor stage I-III were longer in the ER^-PR⁺ group.

CONCLUSION

Disease-specific survival of single HR⁺ tumor cases was longer than that of double HR^- tumors but poorer than double HR⁺ tumors. However, differences in disease-specific survival were not significant between the ER^-PR⁺ and ER^-PR^- groups.

Single hormone receptor-positive breast cancer patients experienced poor survival outcomes: a systematic review and meta-analysis

BACKGROUND

The prognostic and clinical significance of single hormone receptor expression in breast cancer has not been clearly established. The goal of this study was to conduct a meta-analysis to compare the clinical outcomes of patients with ER+PR- tumours and ER-PR+ tumours to those of patients with ER+PR+ tumours.

METHODS

A systematic review of the literature was conducted to identify studies that compared the clinical outcome of patients with ER+PR- tumours or ER-PR+ tumours with those of patients with ER+PR+ tumours. A total of 18 studies met the inclusion criteria and included 217,485 women. Standard methods for meta-analysis were used, including fixed-effect models.

RESULTS

Patients with ER+PR- tumours or ER-PR+ tumours had significantly worse DFS (HR 1.60, 95% CI 1.44-1.77 and HR 2.27, 95% CI 1.67-3.09), BCSS (HR 1.43, 95% CI 1.33-1.53 and HR 1.82, 95% CI 1.68-1.98) and OS (HR 1.38, 95% CI 1.28-1.47 and HR 1.48, 95% CI 1.17-1.89) than those of patients with ER+PR+ tumours. In subgroup analyses, patients who had ER+PR- tumours experienced a higher risk of recurrence than patients with ER+PR+ tumours in the HER2- (HR 1.57, 95% CI 1.32-1.87), LN - (HR 2.07, 95% CI 1.44-2.86) and endocrine therapy (HR 1.65, 95% CI 1.45-1.89) subgroup. Patients who had HER2- and ER-PR+ tumours had an increased risk of recurrence compared with patients who had HER2- and ER+PR+ tumours (HR 3.10, 95% CI 1.92-5.10).

CONCLUSIONS

Among patients with hormone receptor-positive breast cancer, patients with either ER+PR- tumours or ER-PR+ tumours have a higher risk of recurrence and a shorter survival time than those with ER+PR+ tumours. Patients with both types of breast cancer need additional or better treatments.

Characterization and prognosis of estrogen receptor-positive/progesterone receptor-negative male breast cancer: a population-based study

Background

The aim of this study was to explore the characteristics and prognostic information of estrogen receptor-positive/progesterone receptor-negative (ER+/PR−) male breast cancer.

Methods

Using the US National Cancer Institute’s Surveillance, Epidemiology, and End Results database, we compared the demographics, clinical characteristics, and outcome of estrogen receptor-positive/progesterone receptor-positive (ER+/PR+) patients with ER+/PR− male breast cancer patients from 1990 to 2010. Two thousand three hundred twenty-two patients with ER+/PR+ tumors and 355 patients with ER+/PR− tumors were included in our study.

Results

ER+/PR− patients were younger (P = 0.008) and more likely to be African American (P < 0.001) while presented with higher histological grade (P < 0.001), larger tumor size (P = 0.010), and more invasion to the lymph nodes (P = 0.034) and distant sites (P < 0.001), thus later stage (P = 0.001). Despite higher chance of receiving chemotherapy (51.0% vs 36.5%, P < 0.001), ER+/PR− patients experienced significantly worse breast cancer-specific survival (BSCC) (P < 0.001) and shorter overall survival (OS) (P = 0.003). Multivariate Cox model confirmed that tumor size, lymph node invasion, metastasis, and surgery were independent prognostic factors of both BSCC and OS for ER+/PR− male breast cancer. Age at diagnosis and chemotherapy were significantly associated with OS but not with BSCC.

Conclusion

ER+/PR− male breast cancer was more aggressive and experienced shorter survival than ER+/PR+ patients. The prognosis was mainly associated with tumor size, lymph node invasion, metastasis, and surgery.

Biological and clinical impact of imbalanced progesterone receptor isoform ratios in breast cancer

There is a consensus that progestins and thus their cognate receptor molecules, the progesterone receptors (PR), are essential in the development of the adult mammary gland and regulators of proliferation and lactation. However, a role for natural progestins in breast carcinogenesis remains poorly understood. A hint to that possible role came from studies in which the synthetic progestin medroxyprogesterone acetate was associated with an increased breast cancer risk in women under hormone replacement therapy. However, progestins have been also used for breast cancer treatment and to inhibit the growth of several experimental breast cancer models. More recently, PR have been shown to be regulators of estrogen receptor signaling. With all this information, the question is how can we target PR, and if so, which patients may benefit from such an approach? PR are not single unique molecules. Two main PR isoforms have been characterized, PRA and PRB, that exert different functions and the relative abundance of one isoform respect to the other determines the response of PR agonists and antagonists. Immunohistochemistry with standard antibodies against PR do not discriminate between isoforms. In this review, we summarize the current knowledge on the expression of both PR isoforms in mammary glands, in experimental models of breast cancer and in breast cancer patients, to better understand how the PRA/PRB ratio can be exploited therapeutically to design personalized therapeutic strategies.

Circulating anti-Müllerian hormone and breast cancer risk: A study in ten prospective cohorts

A strong positive association has been observed between circulating anti-Müllerian hormone (AMH), a biomarker of ovarian reserve, and breast cancer risk in three prospective studies. Confirming this association is important because of the paucity of biomarkers of breast cancer risk in premenopausal women. We conducted a consortium study including ten prospective cohorts that had collected blood from premenopausal women. A nested case-control design was implemented within each cohort. A total of 2,835 invasive (80%) and in situ (20%) breast cancer cases were individually matched to controls (n = 3,122) on age at blood donation. AMH was measured using a high sensitivity enzyme-linked immunoabsorbent assay. Conditional logistic regression was applied to the aggregated dataset. There was a statistically significant trend of increasing breast cancer risk with increasing AMH concentration (ptrend across quartiles <0.0001) after adjusting for breast cancer risk factors. The odds ratio (OR) for breast cancer in the top vs. bottom quartile of AMH was 1.60 (95% CI = 1.31-1.94). Though the test for interaction was not statistically significant (pinteraction  = 0.15), the trend was statistically significant only for tumors positive for both estrogen receptor (ER) and progesterone receptor (PR): ER+/PR+: ORQ4-Q1  = 1.96, 95% CI = 1.46-2.64, ptrend <0.0001; ER+/PR-: ORQ4-Q1  = 0.82, 95% CI = 0.40-1.68, ptrend  = 0.51; ER-/PR+: ORQ4-Q1  = 3.23, 95% CI = 0.48-21.9, ptrend  = 0.26; ER-/PR-: ORQ4-Q1  = 1.15, 95% CI = 0.63-2.09, ptrend  = 0.60. The association was observed for both pre- (ORQ4-Q1 = 1.35, 95% CI = 1.05-1.73) and post-menopausal (ORQ4-Q1  = 1.61, 95% CI = 1.03-2.53) breast cancer (pinteraction  = 0.34). In this large consortium study, we confirmed that AMH is associated with breast cancer risk, with a 60% increase in risk for women in the top vs. bottom quartile of AMH.

Prognostic role of progesterone receptor expression in a population-based analysis

PURPOSE

The role of progesterone (PR) expression in the management of breast cancer is controversial. The aim of this study is to evaluate the characteristics and prognosis of progesterone status among breast cancers patients in a population-based analysis.

MATERIALS AND METHODS

Through the Tuscan Cancer Registry data on all the invasive breast cancer cases diagnosed during the period 2004-2005 in the provinces of Florence and Prato, central Italy, were retrieved. Histological reports were re-examined to obtain information on the percentage of positive tumor cells for estrogen (ER), progesterone (PR) receptors, Ki67 marker and human epidermal growth factor 2 (HER2). Information on age, stage, differentiation grade were also obtained.

RESULTS

Out of 1487 patients, 28% had PR- breast cancer. These patients were older (p 0.006) than PR+ cancer patients, with more frequently high Ki67 (p < 0.0001), HER2 + (p < 0.0001), ER- (p < 0.0001) tumoral expression. The ER+/PR+ subtype was the most represented (n.1053), while ER-/PR+ was the most rare (n.23); 210 cases (14.1%) ER+ PR- and 201 (13.5%) ER-/PR- cases were found. Analysis of survival by the Cox proportional hazards model showed an independent prognostic value of PR expression (p < 0.0001), also when estrogen, Ki67, HER2 status and age were included. The 5-year cancer-specific survival was 82.1, 86.5, 100, 92% for ER-/PR-, ER+/PR-, ER-/PR+, ER+/PR+ subtype, respectively.

CONCLUSIONS

Our study revealed significant differences in clinicopathological characteristics among breast cancer according to PR expression and confirmed its prognostic independent role, suggesting a role of PR in the improvement of breast cancer prognostic characterization.

Breast cancer in Angola, molecular subtypes: a first glance

Purpose

The aim of this study was to investigate the breast cancer (BC) molecular subtypes according to its surrogate immunohistochemistry (IHC) markers. We conducted a preliminary study, to correlate the clinical pathological profiles and molecular subtypes of breast cancer in Luanda, Angola.

Methods

From January 2011 to 30 December 2014, 140 consecutive cases of microscopically confirmed invasive breast carcinoma were classified regarding histology and IHC (ER, PR, HER2, and Ki-67). Surrogate molecular subtypes were classified according to ESMO recommendations.

Results

All patients were female; the median age was 47 years (24–84 years). Invasive carcinoma NST was the most common type (91.4%) and grade 2 was prevalent (70.7%). Most tumours were locally advanced (stage III – 65% and stage IV – 3.6%). In 140 studied cases, 74 (52.8%) malignancies were hormone receptor positive; 25.7% were luminal A like, 19.3% luminal B and HER2 negative like, 7.9% luminal B and HER2-positive like, 15.7% HER2 positive, and 31.4% were triple negative.

Conclusion

Women’s BC in Luanda-Angola is diagnosed at a young age and at an advanced stage. The two predominant molecular subtypes are HR positive and triple negative. The percentage of HER2-positive BC cases was high. Determining the molecular subtype using surrogate IHC markers has important treatment and prognostic implications for Angolan women with BC. There is an urgent need to study a prospective BC series in order to confirm the present results.

Co-expression and significance of Dok2 and Ras p21 protein activator 1 in breast cancer

Docking protein 2 (Dok2) and Ras p21 protein activator 1 (RASA1) are tumor suppressors which have been identified in numerous solid tumors; however, the association between their expression in breast cancer and patient prognosis remains unclear. A total of 285 consecutive patients diagnosed histopathologically with breast cancer who underwent surgery at Jingzhou Central Hospital were selected for the present study. Dok2 and RASA1 protein were explored using histopathology and western blotting techniques, and the association of patient prognosis with clinicopathological parameters was investigated using univariate and multivariate analyses. Weak expression of Dok2/RASA1 was associated with poorly differentiated breast adenocarcinomas; negatively expressed Dok2 and RASA1 were associated with increased tumor size, a higher proportion of axillary lymph node metastasis and later clinical staging. Additionally, Dok2 and RASA1 expression were associated with disease-free survival of patients with breast cancer. As indicated by Cox's regression analysis, Dok2 and RASA1 expression and the high proportion of axillary lymph node metastasis served as significant independent predictors for the recurrence of breast cancer. The results of the present study suggested that combined Dok2 and RASA1 negative expression may serve as an independent prognostic factor for patients following breast cancer surgery.

Loss of steroid hormone receptors is common in malignant pleural and peritoneal effusions of breast cancer patients treated with endocrine therapy

Discordance in estrogen receptor alpha (ERα), progesterone receptor (PR), androgen receptor (AR) and human epidermal growth factor receptor 2 (HER2) status between primary breast cancers and solid distant metastases (“conversion”) has been reported previously. Even though metastatic spread to the peritoneal and pleural cavities occurs frequently and is associated with high mortality, the rate of receptor conversion and the prognostic implications thereof remain elusive.

We therefore determined receptor conversion in 91 effusion metastases (78 pleural, 13 peritoneal effusions) of 69 patients by immunohistochemistry (IHC) and in situ hybridization. Data were coupled to clinical variables and treatment history.

ERα, PR and AR receptor status converted from positive in the primary tumor to negative in the effusion metastases or vice versa in 25-30%, 30-35% and 46-51% of cases for the 1% and 10% thresholds for positivity, respectively. 19-25% of patients converted clinically relevant from “ERα+ or PR+” to ERα-/PR- and 3-4% from ERα-/PR- to “ERα+ or PR+”. For HER2, conversion was observed in 6% of cases. Importantly, receptor conversion for ERα (p = 0.058) and AR (p < 0.001) was more often seen in patients adjuvantly treated with endocrine therapy. Analogous to this observation, HER2-loss was more frequent in patients adjuvantly treated with trastuzumab (p < 0.001).

Alike solid distant metastases, receptor conversion for ERα, PR, AR and HER2 is a frequent phenomenon in peritoneal and pleural effusion metastases. Adjuvant endocrine and trastuzumab therapy imposes an evolutionary selection pressure on the tumor, leading to receptor loss in effusion metastases. Determination of receptor status in malignant effusion specimens will facilitate endocrine treatment decision-making at this lethal state of the disease, and is hence recommended whenever possible.

Estrogen receptor α (ERα) status evaluation using RNAscope in situ hybridization: a reliable and complementary method for IHC in breast cancer tissues

Estrogen receptor α (ERα) plays a significant role in the development of breast cancer and has been used clinically as an endocrine therapeutic target. Currently, clinical laboratories use immunohistochemistry (IHC) to determine the ERα status of patients in order to distinguish those who would benefit from endocrine therapy. This method is highly subjective, requires a large amount of tumor tissue, and may generate false-negative results. To improve the detection of ERα, we used a new RNA in situ hybridization technique (RNAscope) and compared its use with IHC in 72 breast cancer tissues (47 ERα positive and 25 ERα negative). Then we evaluated ERα mRNA by RT-qPCR with RNAscope. An unobvious difference was found between reverse-transcription quantitative polymerase chain reaction (RT-qPCR) and IHC, but a positive correlation was found between RNAscope and IHC. In addition, breast cancer is a highly heterogeneous cancer, and RNAscope could easily reveal the heterogeneity in breast cancer. Moreover, we found that some ERα IHC-based negative and RNAscope-based positive test results were detected as positive after testing with IHC again. Our findings suggest that RNAscope may be a complementary method for improving the detection of patient ERα status and has potential clinical utility.

Targeting PSG1 to enhance chemotherapeutic efficacy: new application for anti-coagulant the dicumarol

Chemotherapeutic response is critical for the successful treatment and good prognosis in cancer patients. In this study, we analysed the gene expression profiles of preoperative samples from oestrogen receptor (ER)-negative breast cancer patients with different responses to taxane-anthracycline-based (TA-based) chemotherapy, and identified a group of genes that was predictive. Pregnancy specific beta-1-glycoprotein 1 (PSG1) played a central role within signalling pathways of these genes. Inhibiting PSG1 can effectively reduce chemoresistance via a transforming growth factor-β (TGF-β)-related pathway in ER-negative breast cancer cells. Drug screening then identified dicumarol (DCM) to target the PSG1 and inhibit chemoresistance to TA-based chemotherapy in vitro, in vivo, and in clinical samples. Taken together, this study highlights PSG1 as an important mediator of chemoresistance, whose effect could be diminished by DCM.

Multimodal Assessment of Estrogen Receptor mRNA Profiles to Quantify Estrogen Pathway Activity in Breast Tumors

BACKGROUND

Molecular markers have transformed our understanding of the heterogeneity of breast cancer and have allowed the identification of genomic profiles of estrogen receptor (ER)-α signaling. However, our understanding of the transcriptional profiles of ER signaling remains inadequate. Therefore, we sought to identify the genomic indicators of ER pathway activity that could supplement traditional immunohistochemical (IHC) assessments of ER status to better understand ER signaling in the breast tumors of individual patients.

MATERIALS AND METHODS

We reduced ESR1 (gene encoding the ER-α protein) mRNA levels using small interfering RNA in ER⁺ MCF7 breast cancer cells and assayed for transcriptional changes using Affymetrix HG U133 Plus 2.0 arrays. We also compared 1034 ER⁺ and ER^- breast tumors from publicly available microarray data. The principal components of ER activity generated from these analyses and from other published estrogen signatures were compared with ESR1 expression, ER-α IHC, and patient survival.

RESULTS

Genes differentially expressed in both analyses were associated with ER-α IHC and ESR1 mRNA expression. They were also significantly enriched for estrogen-driven molecular pathways associated with ESR1, cyclin D1 (CCND1), MYC (v-myc avian myelocytomatosis viral oncogene homolog), and NFKB (nuclear factor kappa B). Despite their differing constituent genes, the principal components generated from these new analyses and from previously published ER-associated gene lists were all associated with each other and with the survival of patients with breast cancer treated with endocrine therapies.

CONCLUSION

A biomarker of ER-α pathway activity, generated using ESR1-responsive mRNAs in MCF7 cells, when used alongside ER-α IHC and ESR1 mRNA expression, could provide a method for further stratification of patients and add insight into ER pathway activity in these patients.

Clinicopathological characteristics of oestrogen receptor negative, progesterone receptor positive breast cancers: re-evaluating subsets within this group

Aims

The presence of oestrogen and progesterone receptors (ER, PR) in breast carcinoma is an important prognostic indicator as well as a predictor of likely response to hormonal treatment. Current ambiguity surrounds ER-negative (–)/PR-positive (+) breast cancer (BC) as to whether this phenotype exists as a distinct entity. The independent predictive value of PR for treatment considerations is also in question, as some investigators believe ER status to be the single most important therapeutic predictive factor in BC. We undertook this study to determine the existence of ER(–)/PR(+) BC and the prognostic effect, if any, of this phenotype.

Methods

We investigated 267 archival documented ER(–)/PR(+) BCs diagnosed between January 1994 and July 2009. Histological slides were retrieved and reviewed. Tissue microarrays were constructed by selecting two 1 mm cores of tumour per case. Repeat immunohistochemistry was performed for confirmation of the ER(–)/PR(+) status. Clinicopathological parameters including age, ethnicity, tumour size, histological grade, histological subtype, associated ductal carcinoma in situ, lymphovascular invasion and lymph node status were evaluated.

Results

On repeat immunohistochemistry, 92 tumours were confirmed as ER(–)/PR(+) BCs. This phenotype accounted for 1.1% of all BC phenotypes and exhibited different clinicopathological features and survival outcome when compared with other phenotypes. ER(–)/PR(+) tumours showed a trend for an early recurrence and poorer overall survival as compared with the patients with ER(+)/PR(+) tumours and similar to ER(–)/PR(–) tumours.

Conclusions

Our findings suggest that ER(–)/PR(+) BCs exist, although rare, with distinct pathological and clinical characteristics from patients with ER(+)/PR(+) BCs.