Prognostic and predictive value of low estrogen receptor expression in breast cancer

Is Oncotype DX testing informative for breast cancers with low ER expression? A retrospective review from a biomarker testing referral center

PURPOSE

It remains unclear whether patients with HER2-negative, low-estrogen receptor (ER-low)-positive early breast cancer (BC) benefit from Oncotype DX® (ODX) testing.

METHODS

We conducted a retrospective review of cases referred for ODX testing over a seven-year period from a breast biomarker testing referral center (n = 854). For each case, we recorded the ODX Recurrence Score (RS) along with percentage of ER nuclear positivity and staining intensity on immunohistochemistry. Our criteria for ER-low was defined as ≤10% cells with nuclear positivity and/or weak intensity of staining. Slides from all ER-low cases were reviewed and the reported ODX ER gene scores were recorded. We randomly selected a comparator group of 56 patients with ER > 10% positivity and non-weak staining intensity (ER-high).

RESULTS

We identified 27 cases (3.2%) that met our criteria for ER-low. Of these, 92.6% had a high RS (>25), and 7.4% had a RS of 25. All cases with ≤10% ER nuclear positivity had a high RS. Most ER-low cases (85.2%) had ODX quantitative ER gene scores in the negative range, whereas all (100%) ER-high cases had positive ER gene scores.

CONCLUSION

ODX does not appear to add significant additional information to inform treatment decisions for most patients with ER-low BC. Incorporating weak ER staining intensity in addition to low percentage of nuclear positivity identifies about twice as many ER-low patients, although with reduced specificity for high RS. Our study supports the contention that most ER-low early BC should be regarded similarly to ER-negative BC.

Quantitative expression of oestrogen receptor in breast cancer: Clinical and molecular significance

BACKGROUND

Oestrogen receptor (ER) positive breast cancer (BC) patients are eligible for endocrine therapy (ET), regardless of ER immunohistochemical expression level. There is a wide spectrum of ER expression and the response to ET is not uniform. This study aimed to assess the clinical and molecular consequences of ER heterogeneity with respect to ET-response.

METHODS

ER expression, categorised by percentage and staining intensity in a large BC cohort (n = 7559) was correlated with clinicopathological parameters and patient ET response. The Cancer Genome Atlas Data BC cohort (n = 1047) was stratified by ER expression and transcriptomic analysis completed to better understand the molecular basis of ER heterogeneity.

RESULTS

The quantitative proportional increase in ER expression was positively associated with favourable prognostic parameters. Tumours with 1-9% ER expression were characteristically similar to ER-negative (<1%) tumours. Maximum ET-response was observed in tumours with 100% ER expression, with responses significantly different to tumours exhibiting ER at < 100% and significantly decreased survival rates were observed in tumours with 50% and 10% of ER expression. The Histochemical-score (H-score), which considers both staining intensity and percentage, added significant prognostic value over ER percentage alone with significant outcome differences observed at H-scores of 30, 100 and 200. There was a positive correlation between ER expression and ESR1 mRNA expression and expression of ER-regulated genes. Pathway analysis identified differential expression in key cancer-related pathways in different ER-positive groups.

CONCLUSION

ET-response is statistically proportionally related to ER expression with significant differences observed at 10%, 50% and 100%. The H-score adds prognostic and predictive information.

The Clinical and Biological Significance of Estrogen Receptor-Low Positive Breast Cancer

Estrogen receptor (ER) status in breast cancer (BC) is determined using immunohistochemistry (IHC) with nuclear expression in ≥1% of cells defined as ER-positive. BC with 1%-9% expression (ER-low-positive), is a clinically and biologically unique subgroup. In this study, we hypothesized that ER-low-positive BC represents a heterogeneous group with a mixture of ER-positive and ER-negative tumor, which may explain their divergent clinical behavior. A large BC cohort (n = 8171) was investigated and categorized into 3 groups: ER-low-positive (1%-9%), ER-positive (≥10%), and ER-negative (<1%) where clinicopathological and outcome characteristics were compared. A subset of ER-low-positive cases was further evaluated using IHC, RNAscope, and RT-qPCR. PAM50 subtyping and ESR1 mRNA expression levels were assessed in ER-low-positive cases within The Cancer Genome Atlas data set. The reliability of image analysis software in assessment of ER expression in the ER-low-positive category was also assessed. ER-low-positive tumors constituted <2% of BC cases examined and showed significant clinicopathological similarity to ER-negative tumors. Most of these tumors were nonluminal types showing low ESR1 mRNA expression. Further validation of ER status revealed that 45% of these tumors were ER-negative with repeated IHC staining and confirmed by RNAscope and RT-qPCR. ER-low-positive tumors diagnosed on needle core biopsy were enriched with false-positive ER staining. BCs with 10% ER behaved similar to ER-positive, rather than ER-negative or low-positive BCs. Moderate concordance was found in assessment of ER-low-positive tumors, and this was not improved by image analysis. Routinely diagnosed ER-low-positive BC includes a proportion of ER-negative cases. We recommend repeat testing of BC showing 1%-9% ER expression and using a cutoff ≥10% expression to define ER positivity to help better inform treatment decisions.

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.

Impact of estrogen receptor expression level on response to neoadjuvant chemotherapy and prognosis in HER2-negative breast cancers

BACKGROUND

Breast cancers with 1-10% cell staining for estrogen receptor (ER) present particular clinical features. The clinical data of estrogen receptor expression level and treatment effect are limited, particularly regarding chemotherapy benefit. We evaluated the pathologic response to neoadjuvant chemotherapy (NAC) in ER low positive tumors (ER staining 1-10%) and compared it with ER > 10% positive tumors (ER staining > 10%) and ER-negative tumors. We further explored the differences in recurrence and survival with respect to the ER expression level.

METHOD

Patients with stages II and III HER2-negative primary breast cancer who received neoadjuvant chemotherapy followed by definitive surgery were categorized according to their ER percentages into three groups: ER-negative, ER low positive, and ER > 10% positive. Logistic regression models were used to assess the association between each variable and pathologic complete response (pCR). Kaplan‒Meier analysis was used to estimate survival outcomes. Cox models were used to adjust for patient and tumor characteristics.

RESULTS

A total of 241 patients were analyzed. Of all patients included, 22 (9.1%) had ER low positive tumors, 159 (66.0%) had ER > 10% positive tumors, and 60 (24.9%) were ER-negative. Low ER positivity was significantly associated with a higher pCR rate than ER > 10% positivity (OR, 0.249; 95% CI, 0.067-0.923; P = 0.038). After a median follow-up time of 32 months, the disease-free survival (DFS) and overall survival (OS) of the patients with ER low positive tumors were significantly worse than those of the patients with ER > 10% positive tumors but similar to those with ER-negative tumors. After adjustment for covariates, ER low positive tumors were significantly associated with worse DFS than ER > 10% positive tumors.

CONCLUSION

Our results indicated that ER low positive breast cancer presents a better response to neoadjuvant chemotherapy and significantly worse prognosis for patients than those with ER > 10% positive tumors, but similar to the ER-negative group. These data support that this category of patients behaves clinically like patients with ER-negative breast cancer and should be treated differently from patients with ER > 10% positive tumors. Further prospective study is needed.

Consensus guidelines for the management of HR-positive HER2/neu negative early breast cancer in India, SAARC region and other LMIC by DELPHI survey method

BACKGROUND

Precise prognostication is the key to optimum and effective treatment planning for early-stage hormone receptor (HR) positive, HER2/neu negative breast cancer patients. Differences in the breast cancer incidence and tumor anatomical features at diagnosis, pharmacogenomics data between Western and Indian women along with the vast diversity in the economic status and differences in insurance policies of these regions; suggest recommendations put forward for Western women might not be applicable to Indian/Asian women. Opinions from oncologists through a voting survey on various prognostic factors/tools to be considered for planning adjuvant therapy are consolidated in this report for the benefit of oncologists of the sub-continent, SAARC and Asia's LMIC (low and middle-income countries).

METHODS

A three-phase DELPHI survey was conducted to collect opinions on prognostic factors considered for planning adjuvant therapy in early-stage HR+/HER2/neu negative breast cancer patients. A panel of 25 oncologists with expertise in breast cancer participated in the survey conducted in 2021. The experts provided opinions as 'agree' or disagree' or 'not sure' in phases-1 and 2 which were conducted virtually; in the final phase-3, all the panel experts met in person and concluded the survey.

RESULTS

Opinions on 41 statements related to prognostic factors/tools and their implications in planning adjuvant endocrine/chemotherapy were collected. All the statements were supported by the latest data from the clinical trials (prospective/retrospective). The statements with opinions of consensus less than 66% were disseminated in phase-2, and later in phase-3 with supporting literature. In phase-3, all the opinions from panelists were consolidated and guidelines were framed.

CONCLUSIONS

This consensus guideline will assist oncologists of India, SAARC and LMIC countries in informed clinical decision-making on adjuvant treatment in early HR+/HER2/neu negative breast cancer patients.

Progesterone Receptor Expression Level Predicts Prognosis of Estrogen Receptor-Positive/HER2-Negative Young Breast Cancer: A Single-Center Prospective Cohort Study

BACKGROUND

Although estrogen receptor (ER) expression levels affect the prognosis of breast cancer, studies about progesterone receptor (PR) expression levels are insufficient, especially in young breast cancer (YBC). The purpose of this study was to compare clinical characteristics and prognosis according to PR expression levels in invasive breast cancer patients.

METHODS

A prospective cohort study was conducted to identify YBC patients with invasive carcinoma diagnosed at an age of less than 40 years old between 2013 and 2018. Clinicopathologic features and prognosis of ER-positive and human epidermal growth factor receptor 2 (HER2)-negative patients were investigated. Patients were stratified into strong PR (PR-positive cell proportion > 10%), low PR (PR-positive cell proportion = 1~10%), and PR-negative (PR-positive cell proportion < 1%).

RESULTS

Among 458 patients enrolled, 386 (84.3%), 26 (5.7%), and 46 (10.0%) were categorized into strong PR, low PR, and PR-negative groups, respectively. The median follow-up duration was 58.6 months. Compared with the strong PR group, low PR and PR-negative groups were more likely to have high Ki-67 and a high nuclear grade. Low R and PR-negative groups had significantly worse disease-free survival (DFS) and distant metastasis-free survival (DMFS) than the strong PR group (p = 0.0033, p = 0007). Low PR group had an even higher risk of distant metastasis than PR-negative patients. Low PR patients and PR-negative had significantly lower overall survival (OS) rates than strong PR.

CONCLUSION

Low PR might be a prognostic factor of ER-positive/HER2-negative in YBC.

Estrogen Receptor Gene Polymorphism as a Possible Genetic Risk Factor for Treatment Response in ER-Positive Breast Cancer Patients

Estrogen receptor-α (ESR1) single nucleotide polymorphisms (SNPs) have been related to breast cancer (BC) susceptibility. In this retrospective study we investigated ESR1 SNPs in association with survival and treatment response in BC patients. Seven ESR1 SNPs were genotyped using TaqMan probe assay in 100 formalin-fixed paraffin embedded blocks of Egyptian ER⁺BC patients. Log-binomial regression was used to assess the association of 5 ESR1 SNPs with relative risk of non-response to adjuvant-hormonal treatment. We compared the performance of five machine learning classification models for prediction of treatment response. Predictive models were developed using rs1801132, rs2228480, and rs9322354 that were significantly associated with increased risk for non-response along with the relevant clinical features. Survival analysis was performed to detect prognostic significance of ESR1 SNPs in ESR⁺BC patients. rs1801132 (C), rs2228480 (A), and rs9322354 (G) minor alleles significantly increased the risk of non-response to tamoxifen by more than 81, 84, and 117%, respectively, in ER⁺BC patients on anthracycline/anthracycline-taxanes-based chemotherapy. Multivariate Cox regression survival analysis revealed that rs1801132 (C) and large tumor size were independent predictors for poor survival outcome in ER⁺BC. The best response predictive model was a combination random forest, K-nearest neighbor, and decision tree having an area under the curve of 0.94 and an accuracy of 90.8%. Our proposed predictive model based on ESR1 rs1801132, rs2228480, and rs9322354 SNPs represents a promising genetic risk stratification for selection patients who could benefit from tamoxifen therapy in such a way that might facilitate personalized medicine required to improve ER⁺BC patients' outcome.

JMJD6 orchestrates a transcriptional program in favor of endocrine resistance in ER+ breast cancer cells

High expression of Jumonji domain containing protein 6 (JMJD6) is strongly associated with poor prognosis in estrogen receptor positive (ER+) breast cancer. We overexpressed JMJD6 in MCF7 cells (JOE cells) and performed RNA-seq analysis. 76% of differentially expressed genes (DEGs) overlapped with ER target genes. Pathway analysis revealed that JMJD6 upregulated a larger subset of genes related to cell proliferation as compared to ER. Interestingly, JOE cells showed a decrease in ER target gene expression prompting us to check ER levels. Indeed, JOE cells showed a significant decrease in both ESR1 and ER levels and JMJD6 siRNA transfection increased the expression of both. Additionally, JOE cells showed increased RET and ERK1 expression, events associated with resistance to endocrine therapy. Accordingly, JOE cells displayed lower sensitivity and survived better at higher doses of 4-hydroxy tamoxifen (Tam) as compared to parental MCF-7 cells. Conversely, LTED-I and TAM R that resist Tam induced death, showed high expression of JMJD6. Further, JMJD6 siRNA treatment decreased growth and improved Tam sensitivity in TAM R. Comparison of JOE DEGs with known Tam signature genes showed a substantial overlap. Overall, these data suggest that blocking ER alone in patients may not eradicate proliferation of JMJD6 expressing ER+ cells and JMJD6 may predispose and sustain endocrine therapy resistance. We propose that immunostaining for JMJD6 could be developed as a potential marker for predicting endocrine therapy resistance. Further, antagonizing JMJD6 action in women expressing higher amounts of this protein, may offer a greater clinical benefit than endocrine therapy.

Survival in Women Diagnosed With Breast Cancer During Pregnancy

INTRODUCTION

Pregnancy rarely coincides with breast cancer, but when it does, uncertainties remain about how survival is affected. In a nation-wide study, we investigated survival in women diagnosed with breast cancer during pregnancy.

MATERIALS AND METHODS

Through health registries, we identified women with breast cancer at ages 15-44 years from 1973-2016 in Denmark and included 156 who were pregnant at diagnosis and 11,110 who were not. We compared overall mortality in pregnant and non-pregnant women using multivariate Cox regression stratified by time since cancer: <2 and ≥2 years.

RESULTS

During the first 2 years after diagnosis, the hazard ratio of overall death was 2.28 (95% CI: 1.48-3.52) for pregnant versus non-pregnant breast cancer patients after adjustment for age and calendar period and 1.62 (95% CI: 1.05-2.50) after further adjustment for extent of disease. Adjusting for additional tumor characteristics, the hazard ratio was still significantly increased. Beyond the first 2 years, there was no excess mortality.

CONCLUSION

Our study identifies the early period after breast cancer as a period of particular interest in future studies on survival after breast cancer in pregnancy. We found no evidence that survival is affected by pregnancy when 2 or more years have passed since diagnosis.

The prognostic and predictive impact of low estrogen receptor expression in early breast cancer: a systematic review and meta-analysis

INTRODUCTION

Traditionally, estrogen receptor (ER)-positive breast cancer has been defined as tumors with ≥1% positive for ER. The updated American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines recommend that tumors with ER expression of 1%-10% should be classified as ER-low-positive, recognizing the limited clinical evidence on the prognostic and predictive role of low ER expression. We aimed to investigate the predictive role of ER-low expression to neoadjuvant chemotherapy (NeoCT) and the prognostic significance of ER-low expressing breast tumors compared with ER-positive or ER-negative breast tumors.

METHODS

A meta-analysis was conducted using the Meta-analyses Of Observational Studies in Epidemiology (MOOSE) guidelines and eligible articles were identified on PubMed and ISI Web of Science databases. The primary outcome was pathologic complete response and secondary outcomes were disease-free survival (DFS) and overall survival (OS). Twelve retrospective cohort studies were included in the meta-analysis. NeoCT resulted in higher pathologic complete response among patients with ER-low expression compared with ER-positive and comparable to ER-negative. Patients with ER-low breast cancer had a statistically significant worse DFS and OS compared with patients with ER-positive breast cancer, whereas no difference in DFS or OS was observed between ER-low and ER-negative subgroups.

DISCUSSION

The current evidence suggests that ER-low breast cancer has a more similar outcome to ER-negative than to ER-positive breast cancer in terms of DFS and OS. ER-low expression seems also to have a predictive role regarding NeoCT. Considering the certainty of current evidence categorized as low to moderate, our results urge the need for well-designed prospective studies investigating the molecular background and the most appropriate treatment strategy for ER-low expressing breast cancer.

DNA methylation profiling identifies two distinct subgroups in breast cancers with low hormone receptor expression, mainly associated with HER2 amplification status

Background

Current clinical guidelines suggest that breast cancers with low hormone receptor expression (LowHR) in 1–10% of tumor cells should be regarded as hormone receptor positive. However, clinical data show that these patients have worse outcome compared to patients with hormone receptor expression above 10%. We performed DNA methylation profiling on 23 LowHR breast cancer specimens, including 13 samples with HER2 amplification and compared our results with a reference breast cancer cohort from The Cancer Genome Atlas to clarify the status for this infrequent but important patient subgroup.

Results

In unsupervised clustering and dimensionality reduction, breast cancers with low hormone receptor expression that lacked HER2 amplification usually clustered with triple negative breast cancer (TNBC) reference samples (8/10; “LowHR TNBC-like”). In contrast, most specimens with low hormone receptor expression and HER2 amplification grouped with hormone receptor positive cancers (11/13; “LowHR HRpos-like”). We observed highly similar DNA methylation patterns of LowHR TNBC-like samples and true TNBCs. Furthermore, the Ki67 proliferation index of LowHR TNBC-like samples and clinical outcome parameters were more similar to TNBCs and differed from LowHR HRpos-like cases.

Conclusions

We here demonstrate that LowHR breast cancer comprises two epigenetically distinct groups. Our data strongly suggest that LowHR TNBC-like samples are molecularly, histologically and clinically closely related to TNBC, while LowHR HRpos-like specimens are closely related to hormone receptor positive tumors.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13148-021-01176-5.

Outcome of breast cancer patients with low hormone receptor positivity: analysis of a 15-year population-based cohort

BACKGROUND

Guideline recommendations for the treatment of breast cancer with low hormone receptor (HR) expression (1%-9%) are ambiguous and several studies showed more similarities with HR-negative tumors than with HR strongly positive tumors (≥10%). We used a population-based 15-year cohort to compare patient characteristics and outcome of HR low positive tumors with HR-negative and HR strongly positive tumors, respectively.

PATIENTS AND METHODS

A total of 38  560 women diagnosed with early invasive breast cancer between 2004 and 2018 within the scope of the Munich Cancer Registry with 4.9 million inhabitants were included. Descriptive analyses of prognostic factors, treatment, and outcome analyses using the Kaplan-Meier method; cumulative incidence in consideration of competing risks; and multivariate analyses (Cox regression and Fine-Gray model) were conducted. Endpoints were time to local recurrence (TTLR), time to lymph node recurrence (TTLNR), time to metastasis (TTM), overall survival (OS), and relative survival (RS).

RESULTS

A total of 861 patients (2%) had HR low positive, 4862 (13%) HR-negative, and 32  837 (85%) HR strongly positive tumors. Within the HER2-negative cohort (n = 33  366), survival of HR low positive tumors was significantly worse than that of HR strongly positive tumors [OS hazard ratio 0.66 (95% confidence interval 0.55-0.78)], whereas between HR low positive and HR-negative tumors no significant survival difference could be detected [OS hazard ratio 0.93 (95% confidence interval 0.78-1.11)]. TTLR, TTLNR, and TTM showed similar results. By contrast, within the HER2-positive cohort (n = 5194), no statistically significant differences between the three HR groups could be detected in multivariate analyses.

CONCLUSION

Current definitions for HR positivity and its clinical relevance should be reconsidered. Patients with HR low positive/HER2-negative tumors could be regarded and treated similar to patients with triple-negative tumors.

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.

Percentage of Hormone Receptor Positivity in Breast Cancer Provides Prognostic Value: A Single-Institute Study

Background

A majority of breast cancer tumors express estrogen receptor (ER) and/or progesterone receptor (PR); however, the percentage of cancer cells expressing these receptors can range from 0-100%. The prognostic and therapeutic impact of the percentage of cells expressing hormone receptors in breast cancer is not fully understood.

Methods

A retrospective analysis of 411 breast cancer patients who were treated at the University of Nebraska Medical Center between 2010 and 2017 was performed. Patient tumors were evaluated for percentage of cells expressing ER and PR in conjunction with clinical outcomes.

Results

Patient tumors demonstrated a highly bimodal pattern of ER and PR staining with a majority of tumors demonstrating either a high percentage (> 80% of cells) or lack of cells (0%) staining for ER or PR. An increase in the percentage of ER positivity correlated with decreased local recurrence and improved overall survival. An increase in the percentage of PR positivity demonstrated a trend towards decreased local recurrence and improved overall survival, but was not statistically significant.

Conclusions

Results based on both continuous and categorical evaluation of ER expression revealed that increasing expression correlated with improved patient outcomes. Similar evaluation of PR expression demonstrated a trend towards improved patient outcomes though not statistically significant. These findings suggest that the degree of hormone receptor positivity and not a Boolean representation of positivity could provide additional prognostic value in the treatment and management of breast cancer.

Prognostic and predictive parameters in breast pathology: a pathologist's primer

The pathologist's role in the breast cancer treatment team has evolved from rendering a diagnosis of breast cancer, to providing a growing list of prognostic and predictive parameters such that individualized treatment decisions can be made based on likelihood of benefit from additional treatments and potential benefit from specific therapies. In all stages, ER and HER2 status help segregate breast cancers into treatment groups with similar outcomes and treatment response rates, however, traditional pathologic parameters such as favorable histologic subtype, size, lymph node status, and Nottingham grade also have remained clinically relevant in early stage disease decision-making. This is especially true for the most common subtype of breast cancer; ER positive, HER2 negative disease. For this same group of breast cancers, an ever-expanding list of gene-expression panels also can provide prediction and prognostication about potential chemotherapy benefit beyond standard endocrine therapies, with the 21-gene Recurrence Score, currently the only prospectively validated predictive test for this purpose. In the more aggressive ER-negative cancer subtypes, response to neoadjuvant therapy and` the extent of tumor infiltrating lymphocytes (TILs) are more recently recognized powerful prognostic parameters, and clinical guidelines now offer additional treatment options for those high-risk patients with residual cancer after standard neoadjuvant therapy. In stage four disease, predictive tests like germline BRCA status, tumor PIK3CA mutation status (in ER+ metastatic disease) and PDL-1 status (in triple negative metastatic disease) are now used to determine additional new treatment options. The objective of this review is to describe the latest in prognostic and predictive parameters in breast cancer as they are relevant to standard pathology reporting and how they are used in breast cancer clinical treatment decisions.

Secreted breast tumor interstitial fluid microRNAs and their target genes are associated with triple-negative breast cancer, tumor grade, and immune infiltration

Background

Studies on tumor-secreted microRNAs point to a functional role of these in cellular communication and reprogramming of the tumor microenvironment. Uptake of tumor-secreted microRNAs by neighboring cells may result in the silencing of mRNA targets and, in turn, modulation of the transcriptome. Studying miRNAs externalized from tumors could improve cancer patient diagnosis and disease monitoring and help to pinpoint which miRNA-gene interactions are central for tumor properties such as invasiveness and metastasis.

Methods

Using a bioinformatics approach, we analyzed the profiles of secreted tumor and normal interstitial fluid (IF) microRNAs, from women with breast cancer (BC). We carried out differential abundance analysis (DAA), to obtain miRNAs, which were enriched or depleted in IFs, from patients with different clinical traits. Subsequently, miRNA family enrichment analysis was performed to assess whether any families were over-represented in the specific sets. We identified dysregulated genes in tumor tissues from the same cohort of patients and constructed weighted gene co-expression networks, to extract sets of co-expressed genes and co-abundant miRNAs. Lastly, we integrated miRNAs and mRNAs to obtain interaction networks and supported our findings using prediction tools and cancer gene databases.

Results

Network analysis showed co-expressed genes and miRNA regulators, associated with tumor lymphocyte infiltration. All of the genes were involved in immune system processes, and many had previously been associated with cancer immunity. A subset of these, BTLA, CXCL13, IL7R, LAMP3, and LTB, was linked to the presence of tertiary lymphoid structures and high endothelial venules within tumors. Co-abundant tumor interstitial fluid miRNAs within this network, including miR-146a and miR-494, were annotated as negative regulators of immune-stimulatory responses. One co-expression network encompassed differences between BC subtypes. Genes differentially co-expressed between luminal B and triple-negative breast cancer (TNBC) were connected with sphingolipid metabolism and predicted to be co-regulated by miR-23a. Co-expressed genes and TIF miRNAs associated with tumor grade were BTRC, CHST1, miR-10a/b, miR-107, miR-301a, and miR-454.

Conclusion

Integration of IF miRNAs and mRNAs unveiled networks associated with patient clinicopathological traits, and underlined molecular mechanisms, specific to BC sub-groups. Our results highlight the benefits of an integrative approach to biomarker discovery, placing secreted miRNAs within a biological context.

Estrogen and Progesterone Receptor Testing in Breast Cancer: American Society of Clinical Oncology/College of American Pathologists Guideline Update

PURPOSE.—

To update key recommendations of the American Society of Clinical Oncology/College of American Pathologists estrogen receptor (ER) and progesterone receptor (PgR) testing in breast cancer guideline.

METHODS.—

A multidisciplinary international Expert Panel was convened to update the clinical practice guideline recommendations informed by a systematic review of the medical literature.

RECOMMENDATIONS.—

The Expert Panel continues to recommend ER testing of invasive breast cancers by validated immunohistochemistry as the standard for predicting which patients may benefit from endocrine therapy, and no other assays are recommended for this purpose. Breast cancer samples with 1% to 100% of tumor nuclei positive should be interpreted as ER positive. However, the Expert Panel acknowledges that there are limited data on endocrine therapy benefit for cancers with 1% to 10% of cells staining ER positive. Samples with these results should be reported using a new reporting category, ER Low Positive, with a recommended comment. A sample is considered ER negative if < 1% or 0% of tumor cell nuclei are immunoreactive. Additional strategies recommended to promote optimal performance, interpretation, and reporting of cases with an initial low to no ER staining result include establishing a laboratory-specific standard operating procedure describing additional steps used by the laboratory to confirm/adjudicate results. The status of controls should be reported for cases with 0% to 10% staining. Similar principles apply to PgR testing, which is used primarily for prognostic purposes in the setting of an ER-positive cancer. Testing of ductal carcinoma in situ (DCIS) for ER is recommended to determine potential benefit of endocrine therapies to reduce risk of future breast cancer, while testing DCIS for PgR is considered optional. Additional information can be found at www.asco.org/breast-cancer-guidelines .

Estrogen and Progesterone Receptor Testing in Breast Cancer: ASCO/CAP Guideline Update

PURPOSE

To update key recommendations of the American Society of Clinical Oncology/College of American Pathologists estrogen (ER) and progesterone receptor (PgR) testing in breast cancer guideline.

METHODS

A multidisciplinary international Expert Panel was convened to update the clinical practice guideline recommendations informed by a systematic review of the medical literature.

RECOMMENDATIONS

The Expert Panel continues to recommend ER testing of invasive breast cancers by validated immunohistochemistry as the standard for predicting which patients may benefit from endocrine therapy, and no other assays are recommended for this purpose. Breast cancer samples with 1% to 100% of tumor nuclei positive should be interpreted as ER positive. However, the Expert Panel acknowledges that there are limited data on endocrine therapy benefit for cancers with 1% to 10% of cells staining ER positive. Samples with these results should be reported using a new reporting category, ER Low Positive, with a recommended comment. A sample is considered ER negative if < 1% or 0% of tumor cell nuclei are immunoreactive. Additional strategies recommended to promote optimal performance, interpretation, and reporting of cases with an initial low to no ER staining result include establishing a laboratory-specific standard operating procedure describing additional steps used by the laboratory to confirm/adjudicate results. The status of controls should be reported for cases with 0% to 10% staining. Similar principles apply to PgR testing, which is used primarily for prognostic purposes in the setting of an ER-positive cancer. Testing of ductal carcinoma in situ (DCIS) for ER is recommended to determine potential benefit of endocrine therapies to reduce risk of future breast cancer, while testing DCIS for PgR is considered optional. Additional information can be found at www.asco.org/breast-cancer-guidelines.

Impact of hormonal therapy and other adjuvant therapies on contralateral breast volume change after implant-based breast reconstruction

BACKGROUND

Adjuvant therapy after breast surgery, including tamoxifen or aromatase inhibitors, improves the postoperative outcomes and long-term survival of breast cancer patients. The aim of this study was to determine whether volume changes occurred in the contralateral breast during hormonal or other adjuvant therapies.

METHODS

This study reviewed 90 patients who underwent unilateral breast reconstruction between September 2012 and April 2018 using tissue expanders and a permanent implant after the surgical removal of breast cancer. The volume of the contralateral breast was measured using a cast before the first (tissue expander insertion) and second (permanent implant change) stages of surgery. Changes in breast volume were evaluated to determine whether adjuvant therapy such as hormonal therapy, chemotherapy, and radiation therapy influenced the volume of the contralateral breast.

RESULTS

The group receiving tamoxifen therapy demonstrated a significant decrease in volume compared with the group without tamoxifen (-7.8% vs. 1.0%; P=0.028). The aromatase inhibitor-treated group showed a significant increase in volume compared with those who did not receive therapy (-6.2% vs. 4.5%; P=0.023). There were no significant differences between groups treated with other hormonal therapy, chemotherapy, or radiation therapy.

CONCLUSIONS

Patients who received tamoxifen therapy showed a significant decrease in volume in the contralateral breast, while no significant change in weight or body mass index was found. Our findings suggest that we should choose smaller implants for premenopausal patients, who have a high likelihood of receiving tamoxifen therapy.

Only estrogen receptor "positive" is not enough to predict the prognosis of breast cancer

PURPOSE

Beginning in 2018, biomarkers including estrogen receptor (ER) status were incorporated in the 8th AJCC staging system. ER expression levels were not considered in these changes. We hypothesized that the levels of ER expression could affect the prognosis of breast cancer.

METHODS

A retrospective review was conducted to identify all female patients with invasive breast cancer between 2003 and 2012. ER negative (group I), weakly ER-positive (group II), and strongly ER-positive (group III) were defined as Allred total scores of 0-2, 3-5, and 6-8, respectively. We examined a multigene panel, designated the BCT score, which is a newly developed prognostic model for predicting the risk of a distant metastasis.

RESULTS

Among the 4949 patients enrolled in this study, 1310 (26.5%), 361 (7.3%), and 3277 (66.2%) were categorized as group I, II, and III, respectively. Median F/U duration was 57.8 months. Compared to group III, patients in group II were younger, had larger tumors, and were also more likely to have PR-negative tumors, HER-2 amplification, high Ki-67, and high nuclear grade. Between group II and III, there was a significant difference in OS (P = 0.0764, 0.909, and 0.010, respectively). After adjusting for additional factors that may affect OS, the HR for OS showed higher in group II than in group III. The baseline median BCT score indicated that lower ER expression was associated with significantly higher BCT score (P < 0.0001) and significantly more likely to have high risk group (P < 0.0001) relative to higher levels of ER expression group.

CONCLUSION

ER expression levels affect the prognosis of breast cancer. The risk for patients with weakly ER-positive breast cancer should not be underestimated.