Metastasis dormancy in estrogen receptor-positive breast cancer

Initiation of tumor dormancy by the lymphovascular embolus

Cancer dormancy followed by recurrence remains an enigma in cancer biology. Since both local and systemic recurrences are thought to emanate from dormant micrometastasis which take origin from lymphovascular tumor emboli we wondered whether the process of dormancy might initiate within lymphovascular emboli. This study combines experimental studies with a patient-derived xenograft (PDX) of inflammatory breast cancer (Mary-X) that spontaneously forms spheroids in vitro and budding lymphovascular tumor emboli in vivo with observational studies utilizing tissue microarrays (TMAs) of human breast cancers. In the experimental studies, Mary-X during both lymphovascular emboli formation in vivo and spheroidgenesis in vitro exhibited decreased proliferation, a G0/G1 cell cycle arrest and decreased mTOR signaling. This induction of dormancy required calpain-mediated E-cadherin proteolysis and was mediated by decreased P13K signaling, resulting in decreased mTOR activity. In observational human breast cancer studies, increased E-cadherin immunoreactivity due to increased E-cad/NTF-1 but both decreased Ki-67 and mTOR activity was observed selectively and differentially within the lymphovascular tumor emboli. Both our experimental as well as observational studies indicate that in vivo lymphovascular tumor emboli and their in vitro spheroid equivalent initiate dormancy through these pathways.

Leveraging preclinical models of metastatic breast cancer

Women that present to the clinic with established breast cancer metastases have limited treatment options. Yet, the majority of preclinical studies are actually not directed at developing treatment regimens for established metastatic disease. In this review we will discuss the current state of preclinical macro-metastatic breast cancer models, including, but not limited to syngeneic GEMM, PDX and xenografts. Challenges within these models which are often overlooked include fluorophore-immunogenic neoantigens, differences in experimental vs spontaneous metastasis and tumor heterogeneity. Furthermore, due to cell plasticity in the tumor immune microenvironment (TIME) of the metastatic landscape, the treatment efficacy of newly approved immune checkpoint blockade (ICB) may differ in metastatic sites as compared to primary localized tumors.

An image-based screen for secreted proteins involved in breast cancer G0 cell cycle arrest

Secreted proteins regulate the balance between cellular proliferation and G0 arrest and therefore play important roles in tumour dormancy. Tumour dormancy presents a significant clinical challenge for breast cancer patients, where non-proliferating, G0-arrested cancer cells remain at metastatic sites, below the level of clinical detection, some of which can re-enter proliferation and drive tumour relapse. Knowing which secreted proteins can regulate entry into and exit from G0 allows us to manipulate their signalling to prevent tumour relapse. To identify novel secreted proteins that can promote breast cancer G0 arrest, we performed a secretome-wide, image-based screen for proteins that increase the fraction of cells in G0 arrest. From a secretome library of 1282 purified proteins, we identified 29 candidates that promote G0 arrest in non-transformed and transformed breast epithelial cells. The assay we have developed can be adapted for use in other perturbation screens in other cell types. All datasets have been made available for re-analysis and our candidate proteins are presented for alternative bioinformatic refinement or further experimental follow up.

Breast Cancers That Disseminate to Bone Marrow Acquire Aggressive Phenotypes through CX43-related Tumor-Stroma Tunnels

Estrogen receptor-positive (ER+) breast cancer commonly disseminates to bone marrow, where interactions with mesenchymal stromal cells (MSCs) shape disease trajectory. We modeled these interactions with tumor-MSC co-cultures and used an integrated transcriptome-proteome-network-analyses workflow to identify a comprehensive catalog of contact-induced changes. Conditioned media from MSCs failed to recapitulate genes and proteins, some borrowed and others tumor-intrinsic, induced in cancer cells by direct contact. Protein-protein interaction networks revealed the rich connectome between 'borrowed' and 'intrinsic' components. Bioinformatics prioritized one of the 'borrowed' components, CCDC88A /GIV, a multi-modular metastasis-related protein that has recently been implicated in driving a hallmark of cancer, growth signaling autonomy. MSCs transferred GIV protein to ER+ breast cancer cells (that lack GIV) through tunnelling nanotubes via connexin (Cx)43-facilitated intercellular transport. Reinstating GIV alone in GIV-negative breast cancer cells reproduced ∼20% of both the 'borrowed' and the 'intrinsic' gene induction patterns from contact co-cultures; conferred resistance to anti-estrogen drugs; and enhanced tumor dissemination. Findings provide a multiomic insight into MSC→tumor cell intercellular transport and validate how transport of one such candidate, GIV, from the haves (MSCs) to have-nots (ER+ breast cancer) orchestrates aggressive disease states.

Associations amongst genes, molecules, cells, and organs in breast cancer metastasis

This paper is a cross fertilization of ideas about the importance of molecular aspects of breast cancer metastasis by basic scientists, a pathologist, and clinical oncologists at the Henry Ford Health symposium. We address four major topics: (i) the complex roles of lymphatic endothelial cells and the molecules that stimulate them to enhance lymph node and systemic metastasis and influence the anti-tumor immunity that might inhibit metastasis; (ii) the interaction of molecules and cells when breast cancer spreads to bone, and how bone metastases may themselves spread to internal viscera; (iii) how molecular expression and morphologic subtypes of breast cancer assist clinicians in determining which patients to treat with more or less aggressive therapies; (iv) how the outcomes of patients with oligometastases in breast cancer are different from those with multiple metastases and how that could justify the aggressive treatment of these patients with the hope of cure.

Targeting Unique Ligand Binding Domain Structural Features Downregulates DKK1 in Y537S ESR1 Mutant Breast Cancer Cells

Resistance to endocrine therapies remains a major clinical hurdle in breast cancer. Mutations to estrogen receptor alpha (ERα) arise after continued therapeutic pressure. Next generation selective estrogen receptor modulators and degraders/downregulators (SERMs and SERDs) show clinical efficacy, but responses are often non-durable. A tyrosine to serine point mutation at position 537 in the ERα ligand binding domain (LBD) is among the most common and most pathogenic alteration in this setting. It enables endocrine therapy resistance by superceding intrinsic structural-energetic gatekeepers of ER hormone-dependence, it enhances metastatic burden by enabling neomorphic ER-dependent transcriptional programs, and it resists SERM and SERD inhibiton by reducing their binding affinities and abilities to antagonize transcriptional coregulator binding. However, a subset of SERMs and SERDs can achieve efficacy by adopting poses that force the mutation to engage in a new interaction that favors the therapeutic receptor antagonist conformation. We previously described a chemically unconventional SERM, T6I-29, that demonstrates significant anti-proliferative activities in Y537S ERα breast cancer cells. Here, we use a comprehensive suite of structural-biochemical, in vitro, and in vivo approaches to better T6I-29's activities in breast cancer cells harboring Y537S ERα. RNA sequencing in cells treated with T6I-29 reveals a neomorphic downregulation of DKK1, a secreted glycoprotein known to play oncogenic roles in other cancers. Importantly, we find that DKK1 is significantly enriched in ER+ breast cancer plasma compared to healthy controls. This study shows how new SERMs and SERDs can identify new therapeutic pathways in endocrine-resistant ER+ breast cancers.

Targeting Unique Ligand Binding Domain Structural Features Downregulates DKK1 in Y537S ESR1 Mutant Breast Cancer Cells

Resistance to endocrine therapies remains a major clinical hurdle in breast cancer. Mutations to estrogen receptor alpha (ERα) arise after continued therapeutic pressure. Next generation selective estrogen receptor modulators and degraders/downregulators (SERMs and SERDs) show clinical efficacy, but responses are often non-durable. A tyrosine to serine point mutation at position 537 in the ERα ligand binding domain (LBD) is among the most common and most pathogenic alteration in this setting. It enables endocrine therapy resistance by superceding intrinsic structural-energetic gatekeepers of ER hormone-dependence, it enhances metastatic burden by enabling neomorphic ER-dependent transcriptional programs, and it resists SERM and SERD inhibiton by reducing their binding affinities and abilities to antagonize transcriptional coregulator binding. However, a subset of SERMs and SERDs can achieve efficacy by adopting poses that force the mutation to engage in a new interaction that favors the therapeutic receptor antagonist conformation. We previously described a chemically unconventional SERM, T6I-29, that demonstrates significant anti-proliferative activities in Y537S ERα breast cancer cells. Here, we use a comprehensive suite of structural-biochemical, in vitro, and in vivo approaches to better T6I-29's activities in breast cancer cells harboring Y537S ERα. RNA sequencing in cells treated with T6I-29 reveals a neomorphic downregulation of DKK1, a secreted glycoprotein known to play oncogenic roles in other cancers. Importantly, we find that DKK1 is significantly enriched in ER+ breast cancer plasma compared to healthy controls. This study shows how new SERMs and SERDs can identify new therapeutic pathways in endocrine-resistant ER+ breast cancers.

Brain Metastasis of Non-small Cell Lung Cancer After Disease-Free Survival of 5 years: Case Series and Comprehensive Literature Review

BACKGROUND

In the treatment of nonsmall cell lung cancer (NSCLC), a disease-free survival of 5 years is a criterion for cure. This study aimed to evaluate the characteristics and outcomes of patients with brain metastases of NSCLC after a disease-free survival of 5 years (late recurrent brain metastasis [LRBM]).

METHODS

We reviewed 1281 consecutive patients with brain metastasis of lung cancer at a single institute between November 2014 and December 2022. Relevant articles were retrieved from PubMed. Only peer-reviewed journals published in English were included.

RESULTS

Six patients (0.47%) showed LRBM. Three were male. The median age at lung cancer diagnosis was 45 years. The histological diagnosis of all patients was adenocarcinoma. Driver gene mutations were observed in five patients. The median latency period from lung cancer treatment to the development of brain metastasis was 13 years. All patients had no metastasis to any other organs and underwent craniotomies. The median follow-up duration after craniotomy was 3.5 years. No local intracranial recurrences were observed. Three patients had distant intracranial recurrences at 7, 2, and 0.6 years after craniotomy. Five patients survived for 8, 4, 3, 2, and 0.3 years after craniotomy. One patient experienced re-recurrence in the lung 4 years after craniotomy and died 3.7 years later. In our systematic review, only six studies described LRBM of NSCLC.

CONCLUSIONS

LRBM is rare in patients with NSCLC. In our institution, many of these patients harbored driver gene mutations, and achieved long-term survival with aggressive local therapy. Multicenter analysis is mandatory.

Cell-intrinsic and microenvironmental determinants of metastatic colonization

Cancer metastasis is a biologically complex process that remains a major challenge in the oncology clinic, accounting for nearly all of the mortality associated with malignant neoplasms. To establish metastatic growths, carcinoma cells must disseminate from the primary tumour, survive in unfamiliar tissue microenvironments, re-activate programs of proliferation, and escape innate and adaptive immunosurveillance. The entire process is extremely inefficient and can occur over protracted timescales, yielding only a vanishingly small number of carcinoma cells that are able to complete all of the required steps. Here we review both the cancer-cell-intrinsic mechanisms and microenvironmental interactions that enable metastatic colonization. In particular, we highlight recent work on the behaviour of already-disseminated tumour cells, since meaningful progress in treating metastatic disease will clearly require a better understanding of the cells that spawn metastases, which generally have disseminated by the time of initial diagnosis.

Long non-coding RNA SOX2OT in tamoxifen-resistant breast cancer

Hormone receptor (HR)-positive breast cancer can become aggressive after developing hormone-treatment resistance. This study elucidated the role of long non-coding RNA (lncRNA) SOX2OT in tamoxifen-resistant (TAMR) breast cancer and its potential interplay with the tumor microenvironment (TME). TAMR breast cancer cell lines TAMR-V and TAMR-H were compared with the luminal type A cell line (MCF-7). LncRNA expression was assessed via next-generation sequencing, RNA extraction, lncRNA profiling, and quantitative RT-qPCR. SOX2OT overexpression effects on cell proliferation, migration, and invasion were evaluated using various assays. SOX2OT was consistently downregulated in TAMR cell lines and TAMR breast cancer tissue. Overexpression of SOX2OT in TAMR cells increased cell proliferation and cell invasion. However, SOX2OT overexpression did not significantly alter SOX2 levels, suggesting an independent interaction within TAMR cells. Kaplan-Meier plot analysis revealed an inverse relationship between SOX2OT expression and prognosis in luminal A and B breast cancers. Our findings highlight the potential role of SOX2OT in TAMR breast cancer progression. The downregulation of SOX2OT in TAMR breast cancer indicates its involvement in resistance mechanisms. Further studies should explore the intricate interactions between SOX2OT, SOX2, and TME in breast cancer subtypes.

Therapeutic significance of long noncoding RNAs in estrogen receptor-positive breast cancer

About 70% of cases of breast cancer are compromised by Estrogen-positive breast cancer. Through its regulation of several processes, including cell proliferation, cell cycle progression, and apoptosis, Estrogen signaling plays a pivotal role in the genesis and progression of this particular kind of breast cancer. One of the best treatment strategies for treating Estrogen-positive breast cancer is blocking Estrogen signaling. However, patients' treatment failure is mainly caused by the emergence of resistance and metastases, necessitating the development of novel therapeutic targets. Numerous studies have shown long noncoding RNAs (lncRNAs) to play a role in Estrogen-mediated carcinogenesis. These lncRNAs interact with co-regulators and the Estrogen signaling cascade components, primarily due to Estrogen activation. Vimentin and E-cadherin are examples of epithelial-to-mesenchymal transition markers, and they regulate genes involved in cell cycle progression, such as Cyclins, to affect the growth, proliferation, and metastasis of Estrogen-positive breast cancer. Furthermore, a few of these lncRNAs contribute to developing resistance to chemotherapy, making them more desirable targets for enhancing results. Thus, to shed light on the creation of fresh approaches for treating this cancer, this review attempts to compile recently conducted studies on the relationship between lncRNAs and the advancement of Estrogen-positive breast cancer.

Bridging the Gap in Understanding Bone Metastasis: A Multifaceted Perspective

The treatment of patients with advanced cancer poses clinical problems due to the complications that arise as the disease progresses. Bone metastases are a common problem that cancer patients may face, and currently, there are no effective drugs to treat these individuals. Prostate, breast, and lung cancers often spread to the bone, causing significant and disabling health conditions. The bone is a highly active and dynamic tissue and is considered a favorable environment for the growth of cancer. The role of osteoblasts and osteoclasts in the process of bone remodeling and the way in which their interactions change during the progression of metastasis is critical to understanding the pathophysiology of this disease. These interactions create a self-perpetuating loop that stimulates the growth of metastatic cells in the bone. The metabolic reprogramming of both cancer cells and cells in the bone microenvironment has serious implications for the development and progression of metastasis. Insight into the process of bone remodeling and the systemic elements that regulate this process, as well as the cellular changes that occur during the progression of bone metastases, is critical to the discovery of a cure for this disease. It is crucial to explore different therapeutic options that focus specifically on malignancy in the bone microenvironment in order to effectively treat this disease. This review will focus on the bone remodeling process and the effects of metabolic disorders as well as systemic factors like hormones and cytokines on the development of bone metastases. We will also examine the various therapeutic alternatives available today and the upcoming advances in novel treatments.

Noncanonical Activity of Med4 as a Gatekeeper of Metastasis through Epigenetic Control of Integrin Signaling

Breast cancer metastatic relapse after a latency period, known as metastatic dormancy. Through genetic screening in mice, we identified the mediator complex subunit 4 (Med4) as a novel tumor-cell intrinsic gatekeeper in metastatic reactivation. Med4 downregulation effectively awakened dormant breast cancer cells, prompting macroscopic metastatic outgrowth in the lungs. Med4 depletion results in profound changes in nuclear size and three-dimensional chromatin architecture from compacted to relaxed states in contrast to the canonical function of the Mediator complex. These changes rewire the expression of extracellular matrix proteins, integrins, and signaling components resulting in integrin-mediated mechano-transduction and activation of YAP and MRTF. The assembly of stress fibers pulls on the nuclear membrane and contributes to reinforcing the overall chromatin modifications by Med4 depletion. MED4 gene deletions were observed in patients with metastatic breast cancer, and reduced MED4 expression correlates with worse prognosis, highlighting its significance as a potential biomarker for recurrence.

Preclinical Mouse Intraductal Model (MIND) to Study Metastatic Dormancy in Estrogen Receptor-Positive Breast Cancer

Here, we describe a clinically relevant xenograft model of hormone receptor-positive breast cancer that maintains estrogen receptor (ER) status without the need for exogenous supplementation of hormones. The naturally low 17-β-estradiol levels in host mice recapitulate levels seen in post-menopausal women. By introducing breast cancer cells directly into their "natural" microenvironment of the milk ducts, these cells maintain hormone receptor status, model the clinical progression of the disease, and develop ER- metastatic lesions or dormant micrometastatic lesions in the case of ER+ BC. With the use of GFP/RFP:Luc2 reporters, we can monitor in vivo tumour growth and conduct ex vivo metastases assays to evaluate dormant metastatic cell harboring organs. Upon recovery of metastatic cells from ER+ breast cancer models, downstream analyses can be conducted to assess the relationship between epithelial plasticity and metastatic dormancy.

Comparative efficacy and safety of extended adjuvant endocrine therapy for hormone receptor-positive early breast cancer: a Bayesian network meta-analysis

PURPOSE

Optimal extended adjuvant endocrine therapy (ET) duration and strategy for hormone receptor-positive (HR +) early breast cancer remain unclear. In this network meta-analysis (NMA), the efficacy and safety of all available extended adjuvant ETs were compared and ranked.

METHODS

PubMed, Embase, and Cochrane Library and abstracts presented at ASCO, SABCS, and ESMO were searched on March 5, 2022. Fourteen randomized controlled trials (RCTs) comprising eight extended adjuvant ETs for HR + breast cancer and 38,070 patients were analyzed. Main outcomes were disease-free survival (DFS), overall survival (OS), grade ≥ 3 adverse events (AEs), and contralateral breast cancer (CBC). Direct and indirect comparisons were integrated via Bayesian NMA. Hierarchical cluster analysis was performed to jointly rank efficacy and safety outcomes.

RESULTS

Compared with that of 5 year ET, extended 10 year aromatase inhibitor (AI) treatment provided the greatest DFS benefit (HR = 0.45, 95%CrI 0.23-0.83), whereas no strategy differed significantly in terms of the other main outcomes. Extended 10 year AI treatment was the preferred strategy for DFS improvement and CBC prevention (surface under the cumulative ranking curve: 93.51% and 91.29% probability, respectively). All strategies had comparable safeties (grade ≥ 3 AEs). Compared with that of 5 year ET, 10 year extended AI significantly increased arthralgia (OR = 1.65, 95%CrI 1.02-2.93) and osteoporosis (OR = 3.33, 95%CrI 1.19-9.68).

CONCLUSION

Extended 10 year AI therapy may be optimal for HR + early breast cancer given its relatively high efficacy and safety.

Tafazzin mediates tamoxifen resistance by regulating cellular phospholipid composition in ER-positive breast cancer

Tamoxifen is the frontline therapeutic agent for the estrogen receptor-positive (ER + ) subtype of breast cancer patients, which accounts for 70-80% of total breast cancer incidents. However, clinical resistance to tamoxifen has become increasingly common, highlighting the need to identify the underlying cellular mechanisms. In our study, we employed a genome-scale CRISPR-Cas9 loss-of-function screen and validation experiments to discover that Tafazzin (TAZ), a mitochondrial transacylase, is crucial for maintaining the cellular sensitivity of ER+ breast cancer cells to tamoxifen and other chemotherapies. Mechanistically, we found that cardiolipin, whose synthesis and maturation rely on TAZ, is required to maintain cellular sensitivity to tamoxifen. Loss of metabolic enzymatic activity of TAZ causes ERα downregulation and therapy resistance. Interestingly, we observed that TAZ deficiency also led to the upregulation of lysophosphatidylcholine (LPC), which in turn suppressed ERα expression and nuclear localization, thereby contributing to tamoxifen resistance. LPC is further metabolized to lysophosphatidic acid (LPA), a bioactive molecule that supports cell survival. Thus, our findings suggest that the depletion of TAZ promotes tamoxifen resistance through an LPC-LPA phospholipid synthesis axis, and targeting this lipid metabolic pathway could restore cell susceptibility to tamoxifen treatment.

Predictive and prognostic biomarkers of bone metastasis in breast cancer: current status and future directions

The most common site of metastasis in breast cancer is the bone, where the balance between osteoclast-mediated bone resorption and osteoblast-mediated bone formation is disrupted. This imbalance causes osteolytic bone metastasis in breast cancer, which leads to bone pain, pathological fractures, spinal cord compression, and other skeletal-related events (SREs). These complications reduce patients' quality of life significantly and have a profound impact on prognosis. In this review, we begin by providing a brief overview of the epidemiology of bone metastasis in breast cancer, including current diagnostic tools, treatment approaches, and existing challenges. Then, we will introduce the pathophysiology of breast cancer bone metastasis (BCBM) and the animal models involved in the study of BCBM. We then come to the focus of this paper: a discussion of several biomarkers that have the potential to provide predictive and prognostic value in the context of BCBM-some of which may be particularly compatible with more comprehensive liquid biopsies. Beyond that, we briefly explore the potential of new technologies such as single-cell sequencing and organoid models, which will improve our understanding of tumor heterogeneity and aid in the development of improved biomarkers. The emerging biomarkers discussed hold promise for future clinical application, aiding in the prevention of BCBM, improving the prognosis of patients, and guiding the implementation of personalized medicine.

Precision medicine in extended adjuvant endocrine therapy for breast cancer

PURPOSE OF REVIEW

In this review, the evolving role of currently available genomic assays for hormone receptor-positive, early-stage breast cancer in the selection of patients for extended adjuvant endocrine therapy will be discussed.

RECENT FINDINGS

Several studies have investigated the prognostic performance of the Oncotype DX, Breast Cancer Index (BCI), Prosigna, and EndoPredict genomic assays in the late recurrence setting (>5 years after diagnosis), beyond standardly used clinicopathologic parameters, with mixed results. Recently, BCI has also been validated to predict the likelihood of benefit from extended endocrine therapy, though certain data limitations may need to be addressed to justify routine use in clinical practice.

SUMMARY

Even after 5 years of adjuvant endocrine therapy, patients with hormone receptor-positive breast cancer have a significant risk for late recurrence, including distant metastases, that might be prevented with longer durations of endocrine therapy. However, the added toxicity and variable benefit derived from extended endocrine therapy make optimal patient selection crucial. Genomic assays are in development to risk-stratify patients for late recurrence and determine efficacy of extended endocrine therapy, with the aim to help guide extended endocrine therapy decisions for clinicians and individualize treatment strategies for patients.

Tailoring the Amphiphilic Structure of Zwitterionic AIE Photosensitizers to Boost Antitumor Immunity

Although photodynamic therapy (PDT) for thorough cancer treatment is hindered by the limited generation of reactive oxygen species (ROS) with short lifetime from photosensitizers, PDT-induced antitumor immune response remedies the defects. Previous studies show that inducing immunogenic cell deaths is an attractive approach to activate antitumor immunity, which confers a robust adjuvanticity to dying cancer cells. In this work, amphiphilic luminogens with aggregation-induced emission characteristics (AIEgens) are rationally designed and synthesized. By modulating the hydrophobic π-bridge and zwitterionic functional groups, these AIEgens exhibit tunable organelle specificity to lysosome, endoplasmic reticulum, and plasma membrane and enhance ROS generation ability. Notably, the membrane-targeting AIEgen namely TPS-2 induces cell death and membrane rupture via PDT to facilitate the release of antigens and activation of immune cells. Furthermore, the size-controlled TPS-2 nanoaggregates are found to serve as an adjuvant, promoting antigen accumulation and delivery to sufficiently boost the in vivo antitumor immunity by only one dose injection in a prophylactic tumor vaccination model. This work thus provides new insights into optimizing AIE photosensitizers via a hydrophobicity-hydrophilicity balance strategy for evoking an antitumor immunity and directly suppressing the distanced tumor. A single small-molecular system for PDT-stimulated antitumor immunity is envisioned.

Nanoparticle-Based Combination Therapy Enhances Fulvestrant Efficacy and Overcomes Tumor Resistance in ER-Positive Breast Cancer

Nanoparticles (NP) spanning diverse materials and properties have the potential to encapsulate and to protect a wide range of therapeutic cargos to increase bioavailability, to prevent undesired degradation, and to mitigate toxicity. Fulvestrant, a selective estrogen receptor degrader, is commonly used for treating patients with estrogen receptor (ER)-positive breast cancer, but its broad and continual application is limited by poor solubility, invasive muscle administration, and drug resistance. Here, we developed an active targeting motif-modified, intravenously injectable, hydrophilic NP that encapsulates fulvestrant to facilitate its delivery via the bloodstream to tumors, improving bioavailability and systemic tolerability. In addition, the NP was coloaded with abemaciclib, an inhibitor of cyclin-dependent kinases 4 and 6 (CDK4/6), to prevent the development of drug resistance associated with long-term fulvestrant treatment. Targeting peptide modifications on the NP surface assisted in the site-specific release of the drugs to ensure specific toxicity in the tumor tissues and to spare normal tissue. The NP formulation (PPFA-cRGD) exhibited efficient tumor cell killing in both in vitro organoid models and in vivo orthotopic ER-positive breast cancer models without apparent adverse effects, as verified in mouse and Bama miniature pig models. This NP-based therapeutic provides an opportunity for continual and extensive clinical application of fulvestrant, thus indicating its promise as a treatment option for patients with ER-positive breast cancer.

SIGNIFICANCE

A smart nanomedicine encapsulating fulvestrant to improve its half-life, bioavailability, and tumor-targeting and coloaded with CDK4/6 inhibitor abemaciclib to block resistance is a safe and effective therapy for ER-positive breast cancer.

17β-estradiol promotes extracellular vesicle release and selective miRNA loading in ERα-positive breast cancer

The causes and consequences of abnormal biogenesis of extracellular vesicles (EVs) are not yet well understood in malignancies, including in breast cancers (BCs). Given the hormonal signaling dependence of estrogen receptor-positive (ER+) BC, we hypothesized that 17β-estradiol (estrogen) might influence EV production and microRNA (miRNA) loading. We report that physiological doses of 17β-estradiol promote EV secretion specifically from ER+ BC cells via inhibition of miR-149-5p, hindering its regulatory activity on SP1, a transcription factor that regulates the EV biogenesis factor nSMase2. Additionally, miR-149-5p downregulation promotes hnRNPA1 expression, responsible for the loading of let-7's miRNAs into EVs. In multiple patient cohorts, we observed increased levels of let-7a-5p and let-7d-5p in EVs derived from the blood of premenopausal ER+ BC patients, and elevated EV levels in patients with high BMI, both conditions associated with higher levels of 17β-estradiol. In brief, we identified a unique estrogen-driven mechanism by which ER+ BC cells eliminate tumor suppressor miRNAs in EVs, with effects on modulating tumor-associated macrophages in the microenvironment.

Rationale and trial design of NATALEE: a Phase III trial of adjuvant ribociclib + endocrine therapy versus endocrine therapy alone in patients with HR+/HER2- early breast cancer

Background

Ribociclib has demonstrated a statistically significant overall survival benefit in pre- and postmenopausal patients with hormone receptor positive/human epidermal growth factor receptor 2 negative (HR+/HER2-) advanced breast cancer. New Adjuvant Trial with Ribociclib [LEE011] (NATALEE) is a trial evaluating the efficacy and safety of adjuvant ribociclib plus endocrine therapy (ET) versus ET alone in patients with HR+/HER2- early nonmetastatic breast cancer (EBC).

Methods/design

NATALEE is a multicenter, randomized, open-label, Phase III trial in patients with HR+/HER2- EBC. Eligible patients include women, regardless of menopausal status, and men aged ⩾18 years. Select patients with stage IIA, stage IIB, or stage III disease (per the anatomic classification in the AJCC Cancer Staging Manual, 8th edition) with an initial diagnosis ⩽18 months prior to randomization are eligible. Patients receiving standard (neo)adjuvant ET are eligible if treatment was initiated ⩽12 months before randomization. Patients undergo 1:1 randomization to ribociclib 400 mg/day (3 weeks on/1 week off) +ET (letrozole 2.5 mg/day or anastrozole 1 mg/day [investigator's discretion] plus goserelin [men or premenopausal women]) or ET alone. Ribociclib treatment duration is 36 months; ET treatment duration is ⩾60 months. The primary end point is invasive disease-free survival.

Discussion

The 36-month treatment duration of ribociclib in NATALEE is extended compared with that in other adjuvant cyclin-dependent kinases 4 and 6 (CDK4/6) inhibitor trials and is intended to maximize efficacy due to longer duration of CDK4/6 inhibition. Compared with the 600-mg/day dose used in advanced breast cancer, the reduced ribociclib dose used in NATALEE may improve tolerability while maintaining efficacy. NATALEE includes the broadest population of patients with HR+/HER2- EBC of any Phase III trial currently evaluating adjuvant CDK4/6 inhibitor treatment.

Trial registration

ClinicalTrials.gov identifier: NCT03701334 (https://clinicaltrials.gov/ct2/show/NCT03701334).

Variation in second breast cancer risk after primary invasive cancer by time since primary cancer diagnosis and estrogen receptor status

BACKGROUND

In women with previously treated breast cancer, occurrence and timing of second breast cancers have implications for surveillance. The authors examined the timing of second breast cancers by primary cancer estrogen receptor (ER) status in the Breast Cancer Surveillance Consortium.

METHODS

Women who were diagnosed with American Joint Commission on Cancer stage I-III breast cancer were identified within six Breast Cancer Surveillance Consortium registries from 2000 to 2017. Characteristics collected at primary breast cancer diagnosis included demographics, ER status, and treatment. Second breast cancer events included subsequent ipsilateral or contralateral breast cancers diagnosed >6 months after primary diagnosis. The authors examined cumulative incidence and second breast cancer rates by primary cancer ER status during 1-5 versus 6-10 years after diagnosis.

RESULTS

At 10 years, the cumulative second breast cancer incidence was 11.8% (95% confidence interval [CI], 10.7%-13.1%) for women with ER-negative disease and 7.5% (95% CI, 7.0%-8.0%) for those with ER-positive disease. Women with ER-negative cancer had higher second breast cancer rates than those with ER-positive cancer during the first 5 years of follow-up (16.0 per 1000 person-years [PY]; 95% CI, 14.2-17.9 per 1000 PY; vs. 7.8 per 1000 PY; 95% CI, 7.3-8.4 per 1000 PY, respectively). After 5 years, second breast cancer rates were similar for women with ER-negative versus ER-positive breast cancer (12.1 per 1000 PY; 95% CI, 9.9-14.7; vs. 9.3 per 1000 PY; 95% CI, 8.4-10.3 per 1000 PY, respectively).

CONCLUSIONS

ER-negative primary breast cancers are associated with a higher risk of second breast cancers than ER-positive cancers during the first 5 years after diagnosis. Further study is needed to examine the potential benefit of more intensive surveillance targeting these women in the early postdiagnosis period.

A new glance at autophagolysosomal-dependent or -independent function of transcriptional factor EB in human cancer

Autophagy-lysosome system plays a variety of roles in human cancers. In addition to being implicated in metabolism, it is also involved in tumor immunity, remodeling the tumor microenvironment, vascular proliferation, and promoting tumor progression and metastasis. Transcriptional factor EB (TFEB) is a major regulator of the autophagy-lysosomal system. With the in-depth studies on TFEB, researchers have found that it promotes various cancer phenotypes by regulating the autophagolysosomal system, and even in an autophagy-independent way. In this review, we summarize the recent findings about TFEB in various types of cancer (melanoma, pancreatic ductal adenocarcinoma, renal cell carcinoma, colorectal cancer, breast cancer, prostate cancer, ovarian cancer and lung cancer), and shed some light on the mechanisms by which it may serve as a potential target for cancer treatment.

Dynamic bioinspired coculture model for probing ER+ breast cancer dormancy in the bone marrow niche

Late recurrences of breast cancer are hypothesized to arise from disseminated tumor cells (DTCs) that reactivate after dormancy and occur most frequently with estrogen receptor-positive (ER⁺) breast cancer cells (BCCs) in bone marrow (BM). Interactions between the BM niche and BCCs are thought to play a pivotal role in recurrence, and relevant model systems are needed for mechanistic insights and improved treatments. We examined dormant DTCs in vivo and observed DTCs near bone lining cells and exhibiting autophagy. To study underlying cell-cell interactions, we established a well-defined, bioinspired dynamic indirect coculture model of ER⁺ BCCs with BM niche cells, human mesenchymal stem cells (hMSCs) and fetal osteoblasts (hFOBs). hMSCs promoted BCC growth, whereas hFOBs promoted dormancy and autophagy, regulated in part by tumor necrosis factor-α and monocyte chemoattractant protein 1 receptor signaling. This dormancy was reversible by dynamically changing the microenvironment or inhibiting autophagy, presenting further opportunities for mechanistic and targeting studies to prevent late recurrence.

Study of potential inhibition of the estrogen receptor α by cannabinoids using an in silico approach: Agonist vs antagonist mechanism

Breast cancer is the main cancer type with more than 2.2 million cases in 2020, and is the principal cause of death in women; with 685000 deaths in 2020 worldwide. The estrogen receptor is involved at least in 70% of breast cancer diagnoses, and the agonist and antagonist properties of the drug in this receptor play a pivotal role in the control of this illness. This work evaluated the agonist and antagonist mechanisms of 30 cannabinoids by employing molecular docking and dynamic simulations. Compounds with docking scores < -8 kcal/mol were analyzed by molecular dynamic simulation at 300 ns, and relevant insights are given about the protein's structural changes, centered on the helicity in alpha-helices H3, H8, H11, and H12. Cannabicitran was the cannabinoid that presented the best relative binding-free energy (-34.96 kcal/mol), and based on rational modification, we found a new natural-based compound with relative binding-free energy (-44.83 kcal/mol) better than the controls hydroxytamoxifen and acolbifen. Structure modifications that could increase biological activity are suggested.

The complex nature of heterogeneity and its roles in breast cancer biology and therapeutic responsiveness

Heterogeneity is a complex feature of cells and tissues with many interacting components. Depending on the nature of the research context, interacting features of cellular, drug response, genetic, molecular, spatial, temporal, and vascular heterogeneity may be present. We describe the various forms of heterogeneity with examples of their interactions and how they play a role in affecting cellular phenotype and drug responses in breast cancer. While cellular heterogeneity may be the most widely described and invoked, many forms of heterogeneity are evident within the tumor microenvironment and affect responses to the endocrine and cytotoxic drugs widely used in standard clinical care. Drug response heterogeneity is a critical determinant of clinical response and curative potential and also is multifaceted when encountered. The interactive nature of some forms of heterogeneity is readily apparent. For example, the process of metastasis has the properties of both temporal and spatial heterogeneity within the host, whereas each individual metastatic deposit may exhibit cellular, genetic, molecular, and vascular heterogeneity. This review describes the many forms of heterogeneity, their integrated activities, and offers some insights into how heterogeneity may be understood and studied in the future.

The Utility of Breast Cancer Index (BCI) Over Clinical Prognostic Tools for Predicting the Need for Extended Endocrine Therapy: A Safety Net Hospital Experience

INTRODUCTION

Extended endocrine therapy (EET) benefits select patients with early-stage hormone-receptor positive (HR+) breast cancer (BC) but also incurs side effects and cost. The Clinical Treatment Score at Five Years (CTS5) is a free tool that estimates risks of late relapse in estrogen-receptor positive (ER+) BC using clinicopathologic factors. The Breast Cancer Index (BCI) incorporates 2 genomic assays to estimate late relapse risk and likelihood of benefit from EET. This retrospective study assesses the utility of BCI in selecting EET candidates in a safety net hospital.

MATERIALS AND METHODS

We performed a retrospective chart review on 69 women with early-stage HR+, HER2- BC diagnosed at our institution from December 2009 to February 2016 on whom BCI was submitted. The CTS5 score was also calculated to assess clinical risk of late relapse.

RESULTS

Median age was 53 years. All patients included in our analysis had early ER+ HER2-negative BC. Roughly half of the patients (55%) were postmenopausal and 61% were of Hispanic origin. A total of 34 patients (49%) were deemed high-risk (>5%) for late relapse by CTS5, compared to 42 (61%) by BCI. BCI identified 31 (45%) patients that would benefit from EET and of those, 74%% were advised EET. 16 (47%) clinical high-risk patients were advised against EET due to low benefit predicted by BCI. In the clinical low risk group, 9 (26%) were recommended EET based on high benefit predicted by BCI.

CONCLUSION

BCI is reasonable to consider in early-stage HR+ BC and offered clinically relevant information over clinical pathologic information alone.

Total Tumor Load to assist in the decision for additional axillary surgery in the positive sentinel node breast cancer patients

The Total Tumor Load (TTL) concept has been demonstrated to accurately predict the status of the non-sentinel lymph nodes (NSLN) in breast cancer patients. In 2019, our center implemented the TTL cut-off of 30,000 CK19 mRNA copies/μL as sole criterion for deciding on performing ALND. This retrospective, unicentric, study analyzed 87 cT1-3N0 breast cancer patients treated consecutively in a period of two years and aimed to evaluate the performance of this criterion. Secondary objectives included the comparison of the criterion versus our previous Clinical Decision Rule (CDR) versus ACOSOG Z0011 criteria for avoiding an ALND in proportion of patients spared an ALND and in proportion of patients left with a surgically untreated metastasized axilla. An interim analysis revealed new TTL cut-offs for deciding on performing an ALND. The 30,000 CK19 mRNA copies/μL criterion yielded an area under the ROC Curve (AUC) of 0.849, a false positive (FP) rate of 30.1% and a positive predictive value (PPV) of 38.9%. The 30,000 CK19 mRNA copies/μL criterion spared 58.6% of the patients an ALND versus 41.4% with CDR versus 73.6% with Z0011 and left 0.0% patients with a surgically untreated metastasized axilla versus 21.4% with CDR versus 42.9% with Z0011. The new TTL cut-off of 260,000 CK19 mRNA copies/μL for deciding on an ALND yielded an AUC of 0.753, a FP rate of 13.7% and a PPV of 47.4%. This new criterion spared 78.2% of the study sample an ALND and left 35.7% of metastasized axillae surgically untreated. This study emphasizes the need to find a new balance between locoregional control and the morbidity associated with Berg levels I + II axillary lymph node dissection.

Estrone, the major postmenopausal estrogen, binds ERa to induce SNAI2, epithelial-to-mesenchymal transition, and ER+ breast cancer metastasis

Recent work showed that the dominant post-menopausal estrogen, estrone, cooperates with nuclear factor κB (NF-κB) to stimulate inflammation, while pre-menopausal 17β-estradiol opposes NF-κB. Here, we show that post-menopausal estrone, but not 17β-estradiol, activates epithelial-to-mesenchymal transition (EMT) genes to stimulate breast cancer metastasis. HSD17B14, which converts 17β-estradiol to estrone, is higher in cancer than normal breast tissue and in metastatic than primary cancers and associates with earlier metastasis. Treatment with estrone, but not 17β-estradiol, and HSD17B14 overexpression both stimulate an EMT, matrigel invasion, and lung, bone, and liver metastasis in estrogen-receptor-positive (ER+) breast cancer models, while HSD17B14 knockdown reverses the EMT. Estrone:ERα recruits CBP/p300 to the SNAI2 promoter to induce SNAI2 and stimulate an EMT, while 17β-estradiol:ERα recruits co-repressors HDAC1 and NCOR1 to this site. Present work reveals novel differences in gene regulation by these estrogens and the importance of estrone to ER+ breast cancer progression. Upon loss of 17β-estradiol at menopause, estrone-liganded ERα would promote ER+ breast cancer invasion and metastasis.

Epithelial-mesenchymal plasticity determines estrogen receptor positive breast cancer dormancy and epithelial reconversion drives recurrence

More than 70% of human breast cancers (BCs) are estrogen receptor α-positive (ER⁺). A clinical challenge of ER⁺ BC is that they can recur decades after initial treatments. Mechanisms governing latent disease remain elusive due to lack of adequate in vivo models. We compare intraductal xenografts of ER⁺ and triple-negative (TN) BC cells and demonstrate that disseminated TNBC cells proliferate similarly as TNBC cells at the primary site whereas disseminated ER⁺ BC cells proliferate slower, they decrease CDH1 and increase ZEB1,2 expressions, and exhibit characteristics of epithelial-mesenchymal plasticity (EMP) and dormancy. Forced E-cadherin expression overcomes ER⁺ BC dormancy. Cytokine signalings are enriched in more active versus inactive disseminated tumour cells, suggesting microenvironmental triggers for awakening. We conclude that intraductal xenografts model ER + BC dormancy and reveal that EMP is essential for the generation of a dormant cell state and that targeting exit from EMP has therapeutic potential.

Tumor-derived miR-130b-3p induces cancer-associated fibroblast activation by targeting SPIN90 in luminal A breast cancer

Cancer-associated fibroblasts (CAFs) in the tumor microenvironment (TME) interact closely with cancer cells to promote tumor development. Downregulation of SPIN90 in CAFs has been reported to facilitate breast cancer progression, but the underlying mechanism has not been elucidated. Here, we demonstrate that miR-130b-3p directly downregulates SPIN90 in stromal fibroblasts, leading to their differentiation into CAFs. As the decrease of SPIN90 in CAFs was shown to be more prominent in estrogen receptor (ER)-positive breast tumors in this study, miR-130b-3p was selected by bioinformatics analysis of data from patients with ER-positive breast cancer. Ectopic expression of miR-130b-3p in fibroblasts accelerated their differentiation to CAFs that promote cancer cell motility; this was associated with SPIN90 downregulation. We also found that miR-130b-3p was generated in luminal A-type cancer cells and activated fibroblasts after being secreted via exosomes from cancer cells. Finally, miR-130b-3p increased in SPIN90-downregulated tumor stroma of luminal A breast cancer patients and MCF7 cell-xenograft model mice. Our data demonstrate that miR-130b-3p is a key modulator that downregulates SPIN90 in breast CAFs. The inverse correlation between miR-130b-3p and SPIN90 in tumor stroma suggests that the miR-130b-3p/SPIN90 axis is clinically significant for CAF activation during breast cancer progression.

Mechanosensitive Steroid Hormone Signaling and Cell Fate

Mechanical forces collaborate across length scales to coordinate cell fate during development and the dynamic homeostasis of adult tissues. Similarly, steroid hormones interact with their nuclear and nonnuclear receptors to regulate diverse physiological processes necessary for the appropriate development and function of complex multicellular tissues. Aberrant steroid hormone action is associated with tumors originating in hormone-sensitive tissues and its disruption forms the basis of several therapeutic interventions. Prolonged perturbations to mechanical forces may further foster tumor initiation and the evolution of aggressive metastatic disease. Recent evidence suggests that steroid hormone and mechanical signaling intersect to direct cell fate during development and tumor progression. Potential mechanosensitive steroid hormone signaling pathways along with their molecular effectors will be discussed in this context.

The role of cellular quiescence in cancer - beyond a quiet passenger

Quiescence, the ability to temporarily halt proliferation, is a conserved process that initially allowed survival of unicellular organisms during inhospitable times and later contributed to the rise of multicellular organisms, becoming key for cell differentiation, size control and tissue homeostasis. In this Review, we explore the concept of cancer as a disease that involves abnormal regulation of cellular quiescence at every step, from malignant transformation to metastatic outgrowth. Indeed, disrupted quiescence regulation can be linked to each of the so-called 'hallmarks of cancer'. As we argue here, quiescence induction contributes to immune evasion and resistance against cell death. In contrast, loss of quiescence underlies sustained proliferative signalling, evasion of growth suppressors, pro-tumorigenic inflammation, angiogenesis and genomic instability. Finally, both acquisition and loss of quiescence are involved in replicative immortality, metastasis and deregulated cellular energetics. We believe that a viewpoint that considers quiescence abnormalities that occur during oncogenesis might change the way we ask fundamental questions and the experimental approaches we take, potentially contributing to novel discoveries that might help to alter the course of cancer therapy.

NR2F1, a Tumor Dormancy Marker, Is Expressed Predominantly in Cancer-Associated Fibroblasts and Is Associated with Suppressed Breast Cancer Cell Proliferation

BACKGROUND

Tumor dormancy is a crucial mechanism responsible for the late recurrence of breast cancer. Thus, we investigated the clinical relevance of the expression of NR2F1, a known dormancy biomarker.

METHODS

A total of 6758 transcriptomes of bulk tumors from multiple breast cancer patient cohorts and two single-cell sequence cohorts were analyzed.

RESULTS

Breast cancer (BC) with high NR2F1 expression enriched TGFβ signaling, multiple metastases, and stem cell-related pathways. Cell proliferation-related gene sets were suppressed, and MKi67 expression was lower in high NR2F1 BC. In tumors with high Nottingham grade, NR2F1 expression was found to be lower. There was no consistent relationship between NR2F1 expression and metastasis or survival. Cancer mutation rates, immune responses, and immune cell infiltrations were lower in high NR2F1 tumors, whereas the infiltration of stromal cells including cancer-associated fibroblasts (CAFs) was higher. NR2F1 was predominantly expressed in CAFs, particularly inflammatory CAFs, rather than in cancer cells, consistently in the two single-cell sequence cohorts.

CONCLUSIONS

NR2F1 expression in breast cancer is associated with tumor dormancy traits, and it is predominantly expressed in CAFs in the tumor microenvironment.

Exploiting Mouse Models to Recapitulate Clinical Tumor Dormancy and Recurrence in Breast Cancer

Breast cancer recurrence and metastasis from activated dormant tumors remain the leading causes in disease morbidity. Estrogen receptor positive breast cancer that accounts for nearly 80% of all cases face a life-long risk of relapse after initial treatment. The biology of dormant tumors and dormant cancer cells that give rise to recurrent disease and metastasis remain to be understood for us to overcome the clinical challenges that they bring. The selection and optimization of pre-clinical models to recapitulate dormancy and recurrence in patients is critical for studying the underlying cellular and environmental factors. Here, we provide a brief review of studies that utilize mouse models to dissect the mechanisms of dormancy and therapeutic strategies to avert recurrence. This review specifically accentuates the versatility and benefits of immunocompetent transgenic mouse models that can be manipulated to recapitulate primary dormancy, metastatic dormancy, and post-therapy dormancy.

Combining TMEM Doorway Score and MenaCalc Score Improves the Prediction of Distant Recurrence Risk in HR+/HER2- Breast Cancer Patients

PURPOSE

to develop several digital pathology-based machine vision algorithms for combining TMEM and MenaCalc scores and determine if a combination of these biomarkers improves the ability to predict development of distant metastasis over and above that of either biomarker alone.

METHODS

This retrospective study included a subset of 130 patients (65 patients with no recurrence and 65 patients with a recurrence at 5 years) from the Calgary Tamoxifen cohort of breast cancer patients. Patients had confirmed invasive breast cancer and received adjuvant tamoxifen therapy. Of the 130 patients, 86 cases were suitable for analysis in this study. Sequential sections of formalin-fixed paraffin-embedded patient samples were stained for TMEM doorways (immunohistochemistry triple staining) and MenaCalc (immunofluorescence staining). Stained sections were imaged, aligned, and then scored for TMEM doorways and MenaCalc. Different ways of combining TMEM doorway and MenaCalc scores were evaluated and compared to identify the best performing combined marker by using the restricted mean survival time (RMST) difference method.

RESULTS

the best performing combined marker gave an RMST difference of 5.27 years (95% CI: 1.71-8.37), compared to 3.56 years (95% CI: 0.95-6.1) for the associated standalone TMEM doorway analysis and 2.94 years (95% CI: 0.25-5.87) for the associated standalone MenaCalc analysis.

CONCLUSIONS

combining TMEM doorway and MenaCalc scores as a new biomarker improves prognostication over that observed with TMEM doorway or MenaCalc Score alone in this cohort of 86 patients.

The ELEANOR non-coding RNA expression contributes to cancer dormancy and predicts late recurrence of ER-positive breast cancer

The recurrence risk of estrogen receptor (ER)-positive breast cancer remains high for a long period of time, unlike the other types of cancer. The late recurrence reflects the ability of cancer cells to remain dormant through various events, including cancer stemness acquisition, but the detailed mechanism is unknown. ESR1 locus enhancing and activating non-coding RNAs (ELEANORS) are a cluster of nuclear non-coding RNAs originally identified in a recurrent breast cancer cell model. Although their functions as chromatin regulators in vitro are well characterized, their roles in vivo remain elusive. In this study, we evaluated the clinicopathological features of ELEANORS, using primary and corresponding metastatic breast cancer tissues. The ELEANOR expression was restricted to ER-positive cases and well-correlated with the ER and progesterone receptor expression levels, especially at the metastatic sites. ELEANORS were detected in both primary and metastatic tumors (32% and 29%, respectively), and frequently in postmenopausal cases. Interestingly, after surgery, patients with ELEANOR-positive primary tumors exhibited increased relapse rates after, but not within, 5 years. Multivariate analysis showed that ELEANORS are independent recurrence risk factor. Consistently, analyses with cell lines, mouse xenografts and patient tissues revealed that ELEANORS upregulate a breast cancer stemness gene, CD44, and maintain the cancer stem cell population, which may facilitate tumor dormancy. Our findings highlight a new role of nuclear long non-coding RNAs and their clinical potential as predictive biomarkers and therapeutic targets for late recurrence of ER-positive breast cancer.

Factors associated with overall survival after recurrence in patients with ER-positive/HER2-negative postmenopausal breast cancer: an ad hoc analysis of the JBCRG-C06 Safari study

BACKGROUND

The Safari study (UMIN000015168) was a retrospective, multicenter study in which 1072 consecutive cases of estrogen receptor-positive advanced breast cancer treated using 500 mg fulvestrant were registered. We previously reported the relationship between the patient factors and overall survival after the diagnosis using the same cases and the same factors for the analysis of time to treatment failure in patients with estrogen receptor-positive advanced breast cancer. The current study is an ad hoc analysis that focused on the relationship between the patient factors and overall survival after recurrence by adding factors generally associated with overall survival after recurrence.

METHODS

The overall survival after recurrence in patients with estrogen receptor-positive human epidermal growth factor receptor 2 negative recurrent breast cancer was analyzed via univariate and multivariate analyses with a Cox proportional hazards model.

RESULTS

A total of 598 cases were used for the analysis of overall survival after recurrence. Multivariate analysis revealed that favorable overall survival (median, 6.4 years) was significantly correlated with long time from recurrence to fulvestrant use (≥3 years), low nuclear or histological grade (G3 vs. G1), long time to treatment failure of initial palliative endocrine therapy (≥12 months) and long time to initial palliative chemotherapy (≥2 years).

CONCLUSION

The results of this study indicate that sequential endocrine monotherapy may be a useful treatment option for patients with estrogen receptor-positive/human epidermal growth factor receptor 2 negative recurrent breast cancer who have been successfully treated with initial long-term palliative endocrine therapy.

Mathematical model for the estrogen paradox in breast cancer treatment

Estrogen is known to stimulate the growth of breast cancer, but is also effective in treating the disease. This is referred to as the"estrogen paradox". Furthermore, short-term treatment with estrogen can successfully eliminate breast cancer, whereas long-term treatment can cause cancer recurrence. Studies highlighted clinical correlations between estrogen and the protein p53 which plays a pivotal role in breast cancer suppression. We sought to investigate how the interplay between estrogen and p53 impacts the dynamics of breast cancer, and further explore if this could be a plausible explanation for the estrogen paradox and the paradoxical tumor recurrence that results from prolonged treatment with estrogen. For this, we propose a novel ODE based mathematical model that accounts for dormant and active cancer cells, along with the estrogen hormone and the p53 protein. We analyze the model's global stability behavior using the Poincaré-Bendixson theorem and results from differential inequalities. We also perform a bifurcation analysis and carry out numerical simulations that elucidate the roles of estrogen and p53 in the estrogen paradox and its long term estrogen paradoxical effect. The mathematical and numerical analyses suggest that the apparent paradoxical role of estrogen could be the result of an interplay between estrogen and p53, and provide explicit conditions under which the paradoxical effect of long-term treatment may be prevented.

Potential Influence of Anesthetic Interventions on Breast Cancer Early Recurrence According to Estrogen Receptor Expression: A Sub-Study of a Randomized Trial

Background

Effects of anesthetic interventions on cancer prognosis remain controversial. There is evidence that estrogen receptor (ER)-negative breast cancer patients have an early recurrence peak. We aimed to assess the potential benefit of regional anesthesia-analgesia versus general anesthesia regarding early recurrence in breast cancer according to ER expression.

Methods

Based on a multicenter randomized controlled trial (clinicaltrials.gov, NCT00418457), we included all the patients from Peking Union Medical College Hospital research center in this study. The primary outcome was breast cancer recurrence after surgery. The Cox proportional hazard model was used to compare recurrence between groups.

Results

In total, 1,253 breast cancer patients were included in this sub-study, among whom the median follow-up time was 53 months. In this sub-study, 320 patients were ER-negative, and 933 were ER-positive. As for ER-negative patients, the recurrence risk in the PPA (paravertebral blocks and propofol general anesthesia) group showed no statistical difference compared with the GA (sevoflurane and opioids general anesthesia) group (19.1% versus 23.4%; adjusted HR: 0.80, 95% CI: 0.50–1.30; P = 0.377). In the first 18 months after breast cancer surgery, which is considered as the classical early peak of recurrence, after adjustment for menstruation and the pathological stage of tumor, the decrease of early recurrence observed in the PPA group was not significant compared with the GA group (adjusted HR: 0.63, 95% CI: 0.34–1.14; P = 0.127).

Conclusions

In our study, the effects of early recurrence after breast cancer surgery in both ER-negative and ER-positive patients were similar between regional anesthesia-analgesia and general anesthesia. Large samples of ER-negative patients will be needed to clarify the effects of anesthetic interventions.

Large Animal Models of Breast Cancer

In this mini review the status, advantages, and disadvantages of large animal modeling of breast cancer (BC) will be discussed. While most older studies of large animal BC models utilized canine and feline subjects, more recently there has been interest in development of porcine BC models, with some early promising results for modeling human disease. Widely used rodent models of BC were briefly reviewed to give context to the work on the large animal BC models. Availability of large animal BC models could provide additional tools for BC research, including availability of human-sized subjects and BC models with greater biologic relevance.

Evolving cancer-niche interactions and therapeutic targets during bone metastasis

Many cancer types metastasize to bone. This propensity may be a product of genetic traits of the primary tumour in some cancers. Upon arrival, cancer cells establish interactions with various bone-resident cells during the process of colonization. These interactions, to a large degree, dictate cancer cell fates at multiple steps of the metastatic cascade, from single cells to overt metastases. The bone microenvironment may even influence cancer cells to subsequently spread to multiple other organs. Therefore, it is imperative to spatiotemporally delineate the evolving cancer-bone crosstalk during bone colonization. In this Review, we provide a summary of the bone microenvironment and its impact on bone metastasis. On the basis of the microscopic anatomy, we tentatively define a roadmap of the journey of cancer cells through bone relative to various microenvironment components, including the potential of bone to function as a launch pad for secondary metastasis. Finally, we examine common and distinct features of bone metastasis from various cancer types. Our goal is to stimulate future studies leading to the development of a broader scope of potent therapies.

Genome-wide methylation analyses identifies Non-coding RNA genes dysregulated in breast tumours that metastasise to the brain

Brain metastases comprise 40% of all metastatic tumours and breast tumours are among the tumours that most commonly metastasise to the brain, the role that epigenetic gene dysregulation plays in this process is not well understood. We carried out 450 K methylation array analysis to investigate epigenetically dysregulated genes in breast to brain metastases (BBM) compared to normal breast tissues (BN) and primary breast tumours (BP). For this, we referenced 450 K methylation data for BBM tumours prepared in our laboratory with BN and BP from The Cancer Genome Atlas. Experimental validation on our initially identified genes, in an independent cohort of BP and in BBM and their originating primary breast tumours using Combined Bisulphite and Restriction Analysis (CoBRA) and Methylation Specific PCR identified three genes (RP11-713P17.4, MIR124-2, NUS1P3) that are hypermethylated and three genes (MIR3193, CTD-2023M8.1 and MTND6P4) that are hypomethylated in breast to brain metastases. In addition, methylation differences in candidate genes between BBM tumours and originating primary tumours shows dysregulation of DNA methylation occurs either at an early stage of tumour evolution (in the primary tumour) or at a later evolutionary stage (where the epigenetic change is only observed in the brain metastasis). Epigentic changes identified could also be found when analysing tumour free circulating DNA (tfcDNA) in patient’s serum taken during BBM biopsies. Epigenetic dysregulation of RP11-713P17.4, MIR3193, MTND6P4 are early events suggesting a potential use for these genes as prognostic markers.

Identification of hub genes for early detection of bone metastasis in breast cancer

BACKGROUND

Globally, among all women, the most frequently detected and diagnosed and the most lethal type of cancer is breast cancer (BC). In particular, bone is one of the most frequent distant metastases 24in breast cancer patients and bone metastasis arises in approximately 80% of advanced patients. Thus, we need to identify and validate early detection markers that can differentiate metastasis from non-metastasis breast cancers.

METHODS

GSE55715, GSE103357, and GSE146661 gene expression profiling data were downloaded from the GEO database. There was 14 breast cancer with bone metastasis samples and 8 breast cancer tissue samples. GEO2R was used to screen for differentially expressed genes (DEGs). The volcano plots, Venn diagrams, and annular heatmap were generated by using the ggplot2 package. By using the cluster Profiler R package, KEGG and GO enrichment analyses of DEGs were conducted. Through PPI network construction using the STRING database, key hub genes were identified by cytoHubba. Finally, K-M survival and ROC curves were generated to validate hub gene expression.

RESULTS

By GO enrichment analysis, 143 DEGs were enriched in the following GO terms: extracellular structure organization, extracellular matrix organization, leukocyte migration class II protein complex, collagen tridermic protein complex, extracellular matrix structural constituent, growth factor binding, and platelet-derived growth factor binding. In the KEGG pathway enrichment analysis, DEGs were enriched in Staphylococcus aureus infection, Complement and coagulation cascades, and Asthma. By PPI network analysis, we selected the top 10 genes, including SLCO2B1, STAB1, SERPING1, HLA-DOA, AIF1, GIMAP4, C1orf162, HLA-DMB, ADAP2, and HAVCR2. By using TCGA and THPA databases, we validated 2 genes, SERPING1 and GIMAP4, that were related to the early detection of bone metastasis in BC.

CONCLUSIONS

2 abnormally expressed hub genes could play a pivotal role in the breast cancer with bone metastasis by affecting bone homeostasis imbalance in the bone microenvironment.

Molecular Subtypes, Metastatic Pattern and Patient Age in Breast Cancer: An Analysis of Italian Network of Cancer Registries (AIRTUM) Data

Breast cancer stage at diagnosis, patient age and molecular tumor subtype influence disease progression. The aim of this study was to analyze the relationships between these factors and survival in breast cancer patients among the Italian population using data from the AIRTUM national database. We enrolled women with primary breast cancer from 17 population-based cancer registries. Patients were subdivided into older (>69 years), middle (50–69 years) and younger age groups (<50 years) and their primary tumors categorized into four molecular subtypes based on hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status. There were 8831 patients diagnosed between 2010 and 2012 included. The most represented age group was 50–69 years (41.7%). In 5735 cases the molecular subtype was identified: HER2–/HR+ was the most frequent (66.2%) and HER2+/HR− the least (6.2%). Of the 390 women with metastases at diagnosis, 38% had simultaneous involvement of multiple sites, independent of age and molecular profile. In women with a single metastatic site, bone (20% of cases), liver (11%), lung (7%) and brain (3%) were the most frequent. In the studied age groups with different receptor expression profiles, the tumor metastasized to target organs with differing frequencies, affecting survival. Five-year survival was lowest in women with triple-negative (HER2−/HR–) tumors and women with brain metastases at diagnosis.

How cancer cells remodel lipid metabolism: strategies targeting transcription factors

Reprogramming of lipid metabolism has received increasing recognition as a hallmark of cancer cells because lipid dysregulation and the alteration of related enzyme profiles are closely correlated with oncogenic signals and malignant phenotypes, such as metastasis and therapeutic resistance. In this review, we describe recent findings that support the importance of lipids, as well as the transcription factors involved in cancer lipid metabolism. With recent advances in transcription factor analysis, including computer-modeling techniques, transcription factors are emerging as central players in cancer biology. Considering the limited number and the crucial role of transcription factors associated with lipid rewiring in cancers, transcription factor targeting is a promising potential strategy for cancer therapy.

The regulatory effect of hyaluronan on human mesenchymal stem cells' fate modulates their interaction with cancer cells in vitro

Metastatic spread of cancer cells into a pre-metastatic niche is highly dependent on a supporting microenvironment. Human bone marrow-derived mesenchymal stem cells (bmMSCs) contribute to the tumor microenvironment and promote cancer metastasis by inducing epithelial-to-mesenchymal transition and immune evasion. The underlying mechanisms, however, are incompletely understood. The glycosaminoglycan hyaluronan (HA) is a central component of the extracellular matrix and has been shown to harbor pro-metastatic properties. In this study we investigated the highly disseminating breast cancer and glioblastoma multiforme cell lines MDA-MB-321 and U87-MG which strongly differ in their metastatic potential to evaluate the impact of HA on tumor promoting features of bmMSC and their interaction with tumor cells. We show that adipogenic differentiation of bmMSC is regulated by the HA-matrix. This study reveals that MDA-MB-231 cells inhibit this process by the induction of HA-synthesis in bmMSCs and thus preserve the pro-tumorigenic properties of bmMSC. Furthermore, we show that adhesion of MDA-MB-231 cells to bmMSC is facilitated by the tumor cell-induced HA-rich matrix and is mediated by the HA-receptor LAYN. We postulate that invasive breast cancer cells modulate the HA-matrix of bmMSC to adapt the pre-metastatic niche. Thus, the HA-matrix provides a potential novel therapeutic target to prevent cancer metastasis.

Distant recurrence of endometrial cancer more than 10 years after hysterectomy: a case report

OBJECTIVES

Endometrial cancer is the sixth most common cancer among women and recurrence of after 10 years is extremely rare.

CASE PRESENTATION

We reported a comprehensive review of histopathology, investigations and treatment regarding a woman with distant recurrence of endometrial cancer to rectus abdominis muscle after 23 years from the primary surgery. Previous published literatures of similar case were included into the review analysis. A total of 11 similar cases had been reported. Overall, 9 (81.8%) cases were stage 1 disease and only 2 cases were classified as stage II disease. The majority, 6 (54.5%) cases were endometrial adenocarcinoma. Majority of the cases shared the similarity of low grade endometrial cancer with positive oestrogen receptor immunophynetype.

CONCLUSIONS

Thus, the phenomenon of 'cell dormancy' was hypothesized to explain the mechanism of late recurrence for these cases.