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

ER-/PR+ breast cancer is controlled more effectively with an inflammatory inhibitor than hormonal inhibitor

BACKGROUND

The anti-estrogen tamoxifen is a highly effective hormonal therapy for hormonal-positive (HR+) breast cancer patients; however, the estrogen receptor-negative, progesterone receptor-positive (ER-/PR+) subtype does not give the benefits of tamoxifen. Therefore ER-/PR+ breast cancer has a poor clinical outcome, and novel drug therapy for ER-/PR+ breast cancer could benefit these patients.

METHODS

53,805 gene expressions were characterized into HR+ BC and triple-negative breast cancer (TNBC) and analyzed through Breast Cancer Gene Expression Miner in 4319 breast cancer patient samples. The clinical outcomes including overall survival, distant metastasis-free survival, and relapse-free survival were obtained from the PrognoScan database containing 1190 human breast cancer patient samples. To determine the function of ERα and inflammation-related genes such as USP1, CDC20, and CASP1, we used the CRISPR-Cas9 system or gene knockdown (KD) system. To check tumor cell proliferation and migration of ERα KO breast cancer cell line, we used tamoxifen and the inflammation inhibitor Ac-YVAD-CHO. For further confirmation, cancer growth was checked with the inflammation inhibitor in ERα KO breast cancer cell line using a three-dimensional (3D) organoid tissue culture system (ex vivo).

RESULTS

We found that gene expression in ER-/PR+ hormonal-positive breast cancer is positively related to ER-/PR- very similar to TNBC, not other HR+ breast cancer using a 4319 breast cancer patient database. Especially, inflammation-related genes, USP1, CDC20, and CASP1, which are highly expressed in TNBC, are also upregulated in ER-/PR+ HR+ breast cancer. Suppression of USP1, CDC20, and CASP1 inhibited tumor cell growth and metastasis in ERα KO (ER-/PR +) cell lines. Interestingly, loss of ERα in HR+ cell lines is not responsive to tamoxifen, but highly sensitive to the inflammation inhibitor, Ac-YVAD-CHO. In in vitro and ex vivo (3D organoid) models, inflammation inhibitor-specific blocks ER-/PR+ tumor proliferation and migration.

CONCLUSIONS

These findings suggest that an inflammation inhibitor might be a potential option for therapy for ER-/PR+ HR breast cancer patients.

Impact on the long-term prognosis of FDG PET/CT in luminal-A and luminal-B breast cancer

PURPOSE

The aim of the present study was to explore the prognostic role of 2- deoxy-2-[18F]fluoro-D-glucose PET (FDG PET)/CT in recurrent luminal A and luminal B breast cancer.

MATERIALS AND METHODS

From two institutional databases, we retrospectively retrieved data about breast cancer patients undergoing FDG PET/CT between 2011 and 2018 for the assessment of recurrency. Molecular subtypes of breast cancer were defined based on the expression of estrogen, progesterone, human epidermal growth factor receptor 2 (HER2)-b receptors and proliferation index. Overall survival (OS, intended as the time from PET/CT and the time of death) was registered for each patient, by checking the medical charts. Parametric and survival analyses were computed.

RESULTS

Data of 179 patients were retrieved. Sixty-three patients had luminal A, 88 luminal B and 28 luminal B/He breast cancer. At the time of PET/CT scan, cancer antigen (CA) 15.3 levels was within the normal range in 119 patients, whereas it was increased in 60 patients. FDG PET/CT results were suggestive for disease recurrence in 114 (63.7%) patients. The median time lapse from the FDG PET/CT scan to the last clinical follow-up visit was 51 months (1-192 months). Patients with evidence of a PET/CT scan suggestive for disease recurrence showed a significantly shorter OS (P < 0.001) compared to patients with no PET/CT evidence of recurrence, in each subset of luminal breast cancer. Moreover, PET/CT was able to stratify the prognosis of patients independently from the level of tumor marker.

CONCLUSION

These data suggest that FDG PET/CT may be an attractive prognostic tool in recurrent breast cancer. Our study supports its prognostic role both in luminal A and B-type molecular subtypes, regardless of the CA 15.3 levels.

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.

Hormone Receptor Subtype in Ductal Carcinoma in Situ: Prognostic and Predictive Roles of the Progesterone Receptor

Background

We investigated the prognostic and predictive roles of the hormone receptor (HRc) subtype in patients with ductal carcinoma in situ (DCIS). We focused on identifying the roles of the progesterone receptor (PR) independent of estrogen receptor (ER) status.

Methods

Nationwide data of 12,508 female patients diagnosed with DCIS with a mean follow‐up period of 60.7 months were analyzed. HRc subtypes were classified as ER−/PR−, ER−/PR+, ER+/PR−, and ER+/PR+ based on ER and PR statuses. The Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

The ER+/PR+ group showed better prognoses than the ER+/PR− and ER−/PR− groups in the patients who received tamoxifen therapy (p = .001 and p = .031, respectively). HRc subtype was an independent prognostic factor (p = .028). The tamoxifen therapy group showed better survival than the patients who did not receive tamoxifen, but only in the ER+/PR+ subgroup (p = .002). Tamoxifen therapy was an independent prognostic factor (HR, 0.619; 95% CI, 0.423 − 0.907; p = .014). PR status was a favorable prognostic factor in patients with DCIS who received tamoxifen therapy (p < .001), and it remained a prognostic factor independent of ER status (HR, 0.576; 95% CI, 0.349 − 0.951; p = .031).

Conclusion

The HRc subtype can be used as both a prognostic and predictive marker in patients with newly diagnosed DCIS. Tamoxifen therapy can improve overall survival in the ER+/PR+ subtype. PR status has significant prognostic and predictive roles independent of ER status. Testing for the PR status in addition to the ER status is routinely recommended in patients with DCIS to determine the HRc subtype in clinical settings.

Implications for Practice

The hormone receptor (HRc) subtype was an independent prognostic factor, and the estrogen receptor (ER)+/progesterone receptor (PR) + subtype showed a better survival in patients with ductal carcinoma in situ (DCIS) who received tamoxifen therapy. PR was an independent prognostic factor independent of ER, and PR was a favorable prognostic factor in patients with DCIS who received tamoxifen therapy. The HRc subtype could be used as both a prognostic and predictive marker in patients with newly diagnosed DCIS. Testing of PR status in addition to ER status is routinely recommended for patients with DCIS to determine the HRc subtype in clinical settings.

This study investigated the prognostic and predictive roles of the hormone receptor subtype in patients with newly diagnosed ductal carcinoma in situ, focusing on the prognostic and predictive values of progesterone receptor status independent of estrogen receptor status. The prognostic effect of tamoxifen therapy was also investigated

Deregulation of Transcriptional Enhancers in Cancer

Simple Summary

One of the major challenges in cancer treatments is the dynamic adaptation of tumor cells to cancer therapies. In this regard, tumor cells can modify their response to environmental cues without altering their DNA sequence. This cell plasticity enables cells to undergo morphological and functional changes, for example, during the process of tumour metastasis or when acquiring resistance to cancer therapies. Central to cell plasticity, are the dynamic changes in gene expression that are controlled by a set of molecular switches called enhancers. Enhancers are DNA elements that determine when, where and to what extent genes should be switched on and off. Thus, defects in enhancer function can disrupt the gene expression program and can lead to tumour formation. Here, we review how enhancers control the activity of cancer-associated genes and how defects in these regulatory elements contribute to cell plasticity in cancer. Understanding enhancer (de)regulation can provide new strategies for modulating cell plasticity in tumour cells and can open new research avenues for cancer therapy.

Abstract

Epigenetic regulations can shape a cell’s identity by reversible modifications of the chromatin that ultimately control gene expression in response to internal and external cues. In this review, we first discuss the concept of cell plasticity in cancer, a process that is directly controlled by epigenetic mechanisms, with a particular focus on transcriptional enhancers as the cornerstone of epigenetic regulation. In the second part, we discuss mechanisms of enhancer deregulation in adult stem cells and epithelial-to-mesenchymal transition (EMT), as two paradigms of cell plasticity that are dependent on epigenetic regulation and serve as major sources of tumour heterogeneity. Finally, we review how genetic variations at enhancers and their epigenetic modifiers contribute to tumourigenesis, and we highlight examples of cancer drugs that target epigenetic modifications at enhancers.

Stratification of Estrogen Receptor-Negative Breast Cancer Patients by Integrating the Somatic Mutations and Transcriptomic Data

Patients with estrogen receptor-negative breast cancer generally have a worse prognosis than estrogen receptor-positive patients. Nevertheless, a significant proportion of the estrogen receptor-negative cases have favorable outcomes. Identifying patients with a good prognosis, however, remains difficult, as recent studies are quite limited. The identification of molecular biomarkers is needed to better stratify patients. The significantly mutated genes may be potentially used as biomarkers to identify the subtype and to predict outcomes. To identify the biomarkers of receptor-negative breast cancer among the significantly mutated genes, we developed a workflow to screen significantly mutated genes associated with the estrogen receptor in breast cancer by a gene coexpression module. The similarity matrix was calculated with distance correlation to obtain gene modules through a weighted gene coexpression network analysis. The modules highly associated with the estrogen receptor, called important modules, were enriched for breast cancer-related pathways or disease. To screen significantly mutated genes, a new gene list was obtained through the overlap of the important module genes and the significantly mutated genes. The genes on this list can be used as biomarkers to predict survival of estrogen receptor-negative breast cancer patients. Furthermore, we selected six hub significantly mutated genes in the gene list which were also able to separate these patients. Our method provides a new and alternative method for integrating somatic gene mutations and expression data for patient stratification of estrogen receptor-negative breast cancers.

Loss of progesterone receptor is associated with distinct tyrosine kinase profiles in breast cancer

PURPOSE

The aim of this study was to assess protein tyrosine kinase profiles in primary breast cancer samples in correlation with the distinct hormone and growth receptor profiles ER, PR, and HER2.

EXPERIMENTAL DESIGN

Pamchip® microarrays were used to measure the phosphorylation of 144 tyrosine kinase substrates in 29 ER+ breast cancer samples and cell lines MCF7, BT474 and ZR75-1. mRNA expression data from the METABRIC cohort and publicly available PR chip-sequencing data were used for validation purposes, together with RT-PCR.

RESULTS

In ER+ breast tumors and cell lines, we observed that the loss of PR expression correlated to higher kinase activity in samples and cell lines that were HER2-. A number of kinases, representing mostly proteins within the PI3K/AKT pathway, were identified as responsible for the differential phosphorylation between PR- and PR+ in ER+/HER2- tumors. We used the METABRIC cohort to analyze mRNA expression from 977 ER+/HER2- breast cancers. Twenty four kinase-encoding genes were identified as differentially expressed between PR+ and PR-, dividing ER+/HER2- samples in two distinct clusters with significant differences in survival (p < 0.05). Four kinase genes, LCK, FRK, FGFR4, and MST1R, were identified as potential direct targets of PR.

CONCLUSIONS

Our results suggest that the PR status has a profound effect on tyrosine kinases, especially for FGFR4 and LCK genes, in ER+/HER2- breast cancer patients. The influence of these genes on the PI3K/AKT signaling pathway may potentially lead to novel drug targets for ER+/PR- breast cancer patients.

MST1R (RON) expression is a novel prognostic biomarker for metastatic progression in breast cancer patients

PURPOSE

This study evaluates the prognostic significance of MST1R (RON) expression in breast cancer with respect to disease progression, long-term survival, subtype, and association with conventional prognostic factors.

METHODS

The approach includes interrogation of survival and tumor staging with paired MST1R RNA expression from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) datasets. Protein expression evaluation was performed using immunohistochemistry (IHC) staining of MST1R on breast cancer tissue samples from the Cancer Diagnosis Program Breast Cancer Progression tissue microarray and locally obtained breast tumor tissue samples analyzed with paired survival, metastasis, and subtype.

RESULTS

Data from TCGA (n = 774) show poorer relapse-free survival (RFS) in patients with high MST1R expression (P = 0.32) and no difference in MST1R expression based on tumor stage (P = 0.77) or nodal status (P = 0.94). Patients in the GEO-derived Kaplan-Meier Plotter microarray dataset demonstrate the association of MST1R and poorer overall survival (n = 1402, P = 0.018) and RFS in patients receiving chemotherapy (n = 798, P = 0.041). Patients with high MST1R expression display worse overall survival (P = 0.01) and receiver operator characteristic (ROC) analysis demonstrate the predictive capacity of increased MST1R with early death (P = 0.0017) in IHC-stained samples. Paired IHC-stained breast tumor samples from the primary versus metastatic site show MST1R expression is associated with metastatic progression (P = 0.032), and ROC analysis supports the predictive capacity of MST1R in metastatic progression (P = 0.031). No associations of MST1R with estrogen receptor (ER), progesterone receptor (PR), both ER and PR, HER2 positivity, or triple-negativity were found (P = 0.386, P = 0.766, P = 0.746, P = 0.457, P = 0.947, respectively).

CONCLUSIONS

MST1R expression has prognostic value in breast cancer with respect to survival and metastatic progression. MST1R expression is not associated with tumor stage, nodal status, or subtype.

Beta-Tocotrienol Exhibits More Cytotoxic Effects than Gamma-Tocotrienol on Breast Cancer Cells by Promoting Apoptosis via a P53-Independent PI3-Kinase Dependent Pathway

Studies on tocotrienols have progressively revealed the benefits of these vitamin E isoforms on human health. Beta-tocotrienol (beta-T3) is known to be less available in nature compared to other vitamin E members, which may explain the restricted number of studies on beta-T3. In the present study, we aim to investigate the anti-proliferative effects and the pro-apoptotic mechanisms of beta-T3 on two human breast adenocarcinoma cell lines MDA-MB-231 and MCF7. To assess cell viability, both cell lines were incubated for 24 and 48 h, with different concentrations of beta-T3 and gamma-T3, the latter being a widely studied vitamin E isoform with potent anti-cancerous properties. Cell cycle progression and apoptosis induction upon treatment with various concentrations of the beta-T3 isoform were assessed. The effect of beta-T3 on the expression level of several apoptosis-related proteins p53, cytochrome C, cleaved-PARP-1, Bax, Bcl-2, and caspase-3, in addition to key cell survival proteins p-PI3K and p-GSK-3 α/β was determined using western blot analysis. Beta-tocotrienol exhibited a significantly more potent anti-proliferative effect than gamma-tocotrienol on both cell lines regardless of their hormonal receptor status. Beta-T3 induced a mild G1 arrest on both cell lines, and triggered a mitochondrial stress-mediated apoptotic response in MDA-MB-231 cells. Mechanistically, beta-T3′s anti-neoplastic activity involved the downregulation of phosphorylated PI3K and GSK-3 cell survival proteins. These findings suggest that vitamin E beta-T3 should be considered as a promising anti-cancer agent, more effective than gamma-T3 for treating human breast cancer and deserves to be further studied to investigate its effects in vitro and on other cancer types.

Breast Cancer: A Molecularly Heterogenous Disease Needing Subtype-Specific Treatments

Breast cancer is the most commonly occurring cancer in women. There were over two-million new cases in world in 2018. It is the second leading cause of death from cancer in western countries. At the molecular level, breast cancer is a heterogeneous disease, which is characterized by high genomic instability evidenced by somatic gene mutations, copy number alterations, and chromosome structural rearrangements. The genomic instability is caused by defects in DNA damage repair, transcription, DNA replication, telomere maintenance and mitotic chromosome segregation. According to molecular features, breast cancers are subdivided in subtypes, according to activation of hormone receptors (estrogen receptor and progesterone receptor), of human epidermal growth factors receptor 2 (HER2), and or BRCA mutations. In-depth analyses of the molecular features of primary and metastatic breast cancer have shown the great heterogeneity of genetic alterations and their clonal evolution during disease development. These studies have contributed to identify a repertoire of numerous disease-causing genes that are altered through different mutational processes. While early-stage breast cancer is a curable disease in about 70% of patients, advanced breast cancer is largely incurable. However, molecular studies have contributed to develop new therapeutic approaches targeting HER2, CDK4/6, PI3K, or involving poly(ADP-ribose) polymerase inhibitors for BRCA mutation carriers and immunotherapy.