Comparison of Three Transcytotic Pathways for Distribution to Brain Metastases of Breast Cancer

Advances in drug treatments for brain metastases of breast cancer have improved progression-free survival but new, more efficacious strategies are needed. Most chemotherapeutic drugs infiltrate brain metastases by moving between brain capillary endothelial cells, paracellular distribution, resulting in heterogeneous distribution, lower than that of systemic metastases. Herein, we tested three well-known transcytotic pathways through brain capillary endothelial cells as potential avenues for drug access: transferrin receptor (TfR) peptide, low-density lipoprotein receptor 1 (LRP1) peptide, albumin. Each was far-red labeled, injected into two hematogenous models of brain metastases, circulated for two different times, and their uptake quantified in metastases and uninvolved (nonmetastatic) brain. Surprisingly, all three pathways demonstrated distinct distribution patterns in vivo. Two were suboptimal: TfR distributed to uninvolved brain but poorly in metastases, while LRP1 was poorly distributed. Albumin distributed to virtually all metastases in both model systems, significantly greater than in uninvolved brain (P < 0.0001). Further experiments revealed that albumin entered both macrometastases and micrometastases, the targets of treatment and prevention translational strategies. Albumin uptake into brain metastases was not correlated with the uptake of a paracellular probe (biocytin). We identified a novel mechanism of albumin endocytosis through the endothelia of brain metastases consistent with clathrin-independent endocytosis (CIE), involving the neonatal Fc receptor, galectin-3, and glycosphingolipids. Components of the CIE process were found on metastatic endothelial cells in human craniotomies. The data suggest a reconsideration of albumin as a translational mechanism for improved drug delivery to brain metastases and possibly other central nervous system (CNS) cancers.In conclusion, drug therapy for brain metastasis needs improvement. We surveyed three transcytotic pathways as potential delivery systems in brain-tropic models and found that albumin has optimal properties. Albumin used a novel endocytic mechanism.

Molecular aspects of brain metastases in breast cancer

Brain metastases (BM) are a common and devastating manifestation of breast cancer (BC). BM are particularly frequent in the HER2-positive and triple-negative breast cancer phenotypes and usually occur following the metastatic spread to extracranial sites. Several genes mediating BM and biomarkers predicting their risk in BC have been reported in the past decade. These findings have advanced the understanding of BM pathobiology and paved the way for developing new therapeutic strategies but they still warrant a thorough clinical validation. Hence, a better understanding of the mechanistic aspects of BM and delineating the interactions of tumor cells with the brain microenvironment are of utmost importance. This review discusses the molecular basis of the metastatic cascade: the epithelial-mesenchymal transition, cancer, and tumor microenvironment interaction and intravasation, priming of the metastatic niche in the brain, and survival in the new site. We also outline the postulated mechanisms of BC cells' brain tropism. Finally, we discuss advances in the field of biomarkers (both tissue-based and liquid-based) that predict BM from BC.

Prognostic value of ALK overexpression and molecular abnormalities in high-grade serous ovarian carcinoma

BACKGROUND

ALK receptor tyrosine kinase (ALK) aberrations have an established role in pathogenesis of many neoplasms, but their clinical significance in high grade serous ovarian carcinoma (HGSOC) is unclear.

OBJECTIVE

To analyse the frequency of ALK overexpression, molecular abnormalities of ALK, and their impact on the progression-free survival (PFS) and overall survival (OS) in HGSOC.

METHODS

Protein expression was examined by immunohistochemistry (IHC) using three different clones of anti-ALK antibody. The presence of translocations was analysed using fluorescent in situ hybridization. Next-generation sequencing was used for studying the copy number variation, as well as point mutation and translocations involving other commonly rearranged genes.

RESULTS

ALK overexpression was demonstrated in up to 52% of tumours, whereas ALK copy gains in 8.2%, with no clear impact on survival. ALK point mutations were identified in 13 tumours (8.9%), with 3 belonging to the class IV showing significantly better OS. A trend suggesting better PFS was also noticed in these cases. Additionally, three gene fusions were found: ERBB2-GRB7, PRKCA-BRCA1 and SND1-BRAF, none of which has been previously described in HGSOC.

CONCLUSIONS

HGSOC harbouring activating ALK mutations might be associated with a better survival, while ALK overexpression and ALK amplification does not impact the prognosis.

Pathway-level mutation analysis in primary high-grade serous ovarian cancer and matched brain metastases

Brain metastases (BMs) in ovarian cancer (OC) are a rare event. BMs occur most frequently in high-grade serous (HGS) OC. The molecular features of BMs in HGSOC are poorly understood. We performed a whole-exome sequencing analysis of ten matched pairs of formalin-fixed paraffin-embedded samples from primary HGSOC and corresponding BMs. Enrichment significance (p value; false discovery rate) was computed using the Reactome, the Kyoto Encyclopedia of Genes and Genomes pathway collections, and the Gene Ontology Biological Processes. Germline DNA damage repair variants were found in seven cases (70%) and involved the BRCA1, BRCA2, ATM, RAD50, ERCC4, RPA1, MLHI, and ATR genes. Somatic mutations of TP53 were found in nine cases (90%) and were the only stable mutations between the primary tumor and BMs. Disturbed pathways in BMs versus primary HGSOC constituted a complex network and included the cell cycle, the degradation of the extracellular matrix, cell junction organization, nucleotide metabolism, lipid metabolism, the immune system, G-protein-coupled receptors, intracellular vesicular transport, and reaction to chemical stimuli (Golgi vesicle transport and olfactory signaling). Pathway analysis approaches allow for a more intuitive interpretation of the data as compared to considering single-gene aberrations and provide an opportunity to identify clinically informative alterations in HGSOC BM.

Next-generation probiotics - do they open new therapeutic strategies for cancer patients?

Gut microbiota and its association with cancer development/treatment has been intensively studied during the past several years. Currently, there is a growing interest toward next-generation probiotics (NGPs) as therapeutic agents that alter gut microbiota and impact on cancer development. In the present review we focus on three emerging NGPs, namely Faecalibacterium prausnitzii, Akkermansia muciniphila, and Bacteroides fragilis as their presence in the digestive tract can have an impact on cancer incidence. These NGPs enhance gastrointestinal immunity, maintain intestinal barrier integrity, produce beneficial metabolites, act against pathogens, improve immunotherapy efficacy, and reduce complications associated with chemotherapy and radiotherapy. Notably, the use of NGPs in cancer patients does not have a long history and, although their safety remains relatively undefined, recently published data has shown that they are non-toxigenic. Notwithstanding, A. muciniphila may promote colitis whereas enterotoxigenic B. fragilis stimulates chronic inflammation and participates in colorectal carcinogenesis. Nevertheless, the majority of B. fragilis strains provide a beneficial effect to the host, are non-toxigenic and considered as the best current NGP candidate. Overall, emerging studies indicate a beneficial role of these NGPs in the prevention of carcinogenesis and open new promising therapeutic options for cancer patients.

Patient Eligibility and Results for Brain Metastasis in Phase 3 Trials of Advanced Breast Cancer: A Scoping Review

Simple Summary

Even though up to 20% of patients with cancer eventually develop brain metastases (BM), most clinical trials have historically forbidden the enrolment of individuals with BM. The reasons for this practice include considerations regarding safety and efficacy, but there is a pressing need to verify whether new treatments also work for patients with BM. In this article, we assessed the literature on breast cancer and found that there has been an increase over time of trials allowing enrolment of breast cancer patients with BM, and that when the results for these patients were reported separately, they tended to go in the same direction as those observed for all patients. Our results suggest that further efforts are needed to increase the assessment of new treatments for patients with BM.

Abstract

Background: Although brain metastases (BM) affect 5% of all breast cancer patients and 14% of those with metastatic disease, patients with BM are often excluded from participation in clinical trials. We conducted a structured assessment of the contemporary restrictions to enrolment of, and results for, patients with BM in phase 3 trials published over a period of 23 years in advanced breast cancer. Methods: We used PubMed to search for completed randomized trials published between 01/98 and 12/20. For all eligible trials, two authors independently abstracted data on general characteristics of the studies and detailed information on patient eligibility regarding the presence of BM. Results: We analyzed 210 trials, which enrolled 92,409 eligible patients. Of that total, 162 (77.1%) publications explicitly mentioned eligibility criteria related to the presence of BM and 75 (35.7%) trials reportedly allowed patients with BM, usually with restrictions related to prior brain treatment or stability of lesions. There was a significant increase over time in the percentages of trials allowing patients with BM (p < 0.001), and these trials were more frequently dedicated to HER2-positive or triple-negative disease (p = 0.001). Only 11 trials reported separate results for patients with BM at baseline. The direct treatment activity on BM was usually not reported, although in subgroup analyses the treatment effect in relative terms was usually better among patients with BM than in overall populations. Conclusion: Nearly 36% of phase 3 trials in advanced breast cancer over a 23-year period allowed patients with BM, and this practice is increasing over time. More research is needed to establish the activity of current and promising therapies in patients with BM.

Impact of relative dose intensity of oxaliplatin in adjuvant therapy among stage III colon cancer patients on early recurrence: a retrospective cohort study

Background

Oxaliplatin-based therapy with FOLFOX-4 or CAPOX administered over 6 months remains the standard adjuvant treatment for stage III colon cancer (CC) patients. However, many patients experience dose reduction or early termination of chemotherapy due to oxaliplatin toxicity, which may increase the risk of early recurrence. The objective of this study was to analyze the relationship between the relative dose intensity of oxaliplatin (RDI-O) and early recurrence among stage III CC patients.

Methods

The study included 365 patients treated at five oncology centers in Poland between 2000 and 2014. Survival analysis was performed using the Kaplan-Meier method. Univariate analysis was performed using the Cox proportional hazard model; multivariate analysis was performed with the stepwise forward approach. For all analyses the α level of 0.05 was employed.

Results

The median follow-up was 51.8 months (range 8.2–115.1). Early recurrence < 36 months after surgery occurred in 130 patients (37.8%). In this group 51 (39.2%) and 87 (66.9%) of patients were low and high-risk, respectively. Receipt < 60% of RDI-O was associated with early recurrence within 18 months after surgery (OR = 2.05; 95%CI: 1.18–3.51; p = 0.010), especially in low-risk group (HR = 1.56 (95%CI: 0.96–2.53), p = 0.07). In the multivariate analysis early recurrence was correlated with grade (OR = 2.47; 95% CI: 1.25–4.8; p = 0.008), pN (OR = 2.63; 95% CI: 1.55–4.54; p < 0.001), the number of lymph nodes harvested (OR = 0.51; 95% CI: 0.29–0.86; p = 0.013) and RDI-O (OR = 1.91; 95%CI: 1.06–3.39; p = 0.028). The early vs. late recurrence negatively correlated with OS regardless of the RDI-O (HR = 22.9 (95%CI: 13.9–37.6; p < 0.001).

Conclusions

RDI-O < 60% in adjuvant therapy among stage III CC (especially in low-risk group) increases the risk of early recurrence within 18 months of surgery. Patients with early recurrence showed worse overall survival regardless of the RDI-O.

Combined Assessment of Immune Checkpoint Regulator VISTA on Tumor-Associated Immune Cells and Platelet-to-Lymphocyte Ratio Identifies Advanced Germ Cell Tumors with Higher Risk of Unfavorable Outcomes

Simple Summary

Testicular germ cell tumors (GCTs) are the most common malignancies in young males. The current treatment regimens are usually highly effective and curative. Nevertheless, a portion of patients presents with recurrence or succumbs due to the disease. There is an undoubtful necessity to investigate new prognostic markers to stratify the risk of such events. The current study aimed to evaluate the prognostic significance of markers of the tumor microenvironment and systemic inflammation markers in GCTs. We found that low expression of immune checkpoint proteins VISTA (V-domain Ig suppressor of T cell activation) and PD-L1 (programmed death-ligand 1) on tumor-associated immune cells and elevated inflammatory marker platelet-to-lymphocyte ratio are associated with a higher risk of events in testicular GCTs. It indicates a role of both local anti-tumor immune response and systemic inflammation in these tumors.

Abstract

In the current study, we aimed to investigate whether expression of immune checkpoint proteins (V-domain Ig suppressor of T cell activation (VISTA) and programmed death-ligand 1 (PD-L1)) and markers of systemic inflammation could predict progression/relapse and death in the cohort of 180 patients with testicular germ-cell tumors (GCTs). Expression of PD-L1 and VISTA was assessed by immunohistochemistry utilizing tissue microarrays. To estimate systemic inflammation neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), and platelet-to-lymphocyte ratio (PLR) were calculated. We found high PD-L1 and VISTA expression on tumor-associated immune cells (TAICs) in 89 (49.44%) and 63 (37.22%) of GCTs, respectively, whereas tumor cells besides trophoblastic elements were almost uniformly negative. High PD-L1 was associated with seminomatous histology and lower stage. Relapses in stage I patients occurred predominantly in cases with low numbers of PD-L1 and VISTA-expressing TAICs. In stage II/III disease, the combination of low VISTA-expressing TAICs and high PLR was identified as predictor of shorter event-free survival (HR 4.10; 1.48–11.36, p = 0.006) and overall survival (HR 15.56, 95% CI 1.78–135.51, p = 0.001) independently of tumor histology and location of metastases. We demonstrated that the assessment of immune checkpoint proteins on TAICs may serve as a valuable prognostic factor in patients with high-risk testicular GCTs. Further study is warranted to explore the predictive utility of these biomarkers in GCTs.

Expression of Female Sex Hormone Receptors, Connective Tissue Growth Factor and HER2 in Gallbladder Cancer

Gallbladder cancer (GBC) is a highly malignant tumor with poorly understood etiology. An insight into phenotypic features of this malignancy may add to the knowledge of its carcinogenesis and pave the way to new therapeutic approaches. We assessed the expression of female sex hormone receptors (ERα, ERβ, PR), connective tissue growth factor (CTGF) and HER2 in GBC, and adjacent normal tissue (NT), and determined their prognostic impact. Immunohistochemical (IHC) expression of all biomarkers was performed in formalin-fixed, paraffin-embedded specimens in 60 Caucasian GBC patients (51 women and 9 men). ERβ, cytoPR and CTGF expression were found in 89%, 27%, 91% of GBC, and in 63%, 87%, 100% of NT, respectively. No ERα expression was found in GBC and NT. Strong (3+) HER2 expression by IHC or HER2 amplification was seen in five GBC (10.4%). A positive correlation was found between HER2 and CTGF and ERβ expression in GBC and matched NT. In the multivariate analysis, patient age >70 years, tumor size and ERβ expression in GBC was highly predictive for OS (p = 0.003). The correlation between HER2, CTGF and ERβ expression in GBC and NT may indicate the interaction of these pathways in physiological processes and gallbladder pathology.

Genomic characterization of brain metastases (BM) in high-grade serous ovarian cancer (HGSOC)

e13580

Background: BM are a rare occurrence in ovarian cancer (OC) and their molecular characteristics is virtually unknown. DNA damage repair (DDR) deficiency is prevalent in OC, and co-mutated TP53 and any DDR denotes high tumor mutation burden (TMB). We genetically characterized a unique series of high-grade serous ovarian cancer (HGSOC) patients who developed BM to identify alterations of potential clinical relevance. Methods: Whole-exome sequencing (2x150bp, SureSelectXT Library Prep Kit, Illumina’s NovaSeq platform) was performed in matched BM, primary tumors (PT) and normal tissue. DNA was extracted from FFPE samples using QIAamp DNA FFPE Tissue Kit (Qiagen, Germany). All mutations were checked with Catalogue of Somatic Mutations in Cancer (COSMIC) and Integrative Genomics Viewer (IGV). Results: Study group included 10 HGSOC patients (International Federation of Gynecology and Obstetrics classification (FIGO) II-IV, mean age at diagnosis 48 years, range 35-59). Median time from primary HGSOC diagnosis to BM was 38 months (range, 18 to 149). TP53 somatic mutations were found in both primary tumor (PT) and BM in 8 patients. The other 2 cases harbored TP53 mutations not reported in COSMIC catalogue: p.S60L and intronic TP53 mutation preceding p.I322 (IGV). In 9 cases TP53 mutations coexisted with germline or somatic DNA damage repair deficiency. Four cases contained BRCA1 mutations (all germline), and none harbored germline BRCA2 mutation. Other mutated genes included MLH1 (2 somatic, 2 germline), ATR (4 germline, 1 somatic), AMT (1 somatic), RAD50 (1 somatic), ERCC4 (1 somatic), FANCD2 (1 somatic) and RPA1 (1 germline). Three mutation signatures defined in the COSMIC database were indentified in BM: 6, 20 and 30. In 6 cases these mutations were shared in PT, and in another 4 their presence in PT could not be determined due to technical reasons. Median survival from BM was 31 months (range, 5 to 184). Conclusions: Genomic analysis of BM provides an opportunity to identify potentially clinically informative alterations. Mutational profiles in PT are generally reflected in BM. Detected genetic alterations suggest their potential sensitivity to PARP inhibitors and immunotherapy.

Preventing central nervous system metastases in non-small cell lung cancer

INTRODUCTION

There are no effective central nervous system (CNS) metastases prevention methods in lung cancer patients. Prophylactic cranial irradiation has a limited effectiveness and relatively high toxicity. Systemic chemotherapy is not relevant in reducing the risk of CNS in lung cancer patients. The understanding of molecular background of brain metastases in non-small cell lung cancer (NSCLC) patients could contribute to the development of personalized treatments for such patients. Areas covered: This article summarizes the latest clinical trials concerning the use of radiotherapy, chemotherapy, molecularly targeted therapies, and immunotherapy in lung cancer patients, with particular consideration of brain lung cancer metastasis prevention. The literature search was undertaken via PubMed and EMBASE searches and relevant articles are included in this review. Expert commentary: The recent data supports that EGFR-TKIs and ALK inhibitors are clinically relevant for first-line treatment to prevent and treat CNS metastases in molecularly selected NSCLC patients. In the future, high hopes for the prevention of CNS metastases in NSCLC patients are associated with immunotherapy concerning immune check-points inhibitors.

Comparison of central laboratory assessments of ER, PR, HER2, and Ki67 by IHC/FISH and the corresponding mRNAs (ESR1, PGR, ERBB2, and MKi67) by RT-qPCR on an automated, broadly deployed diagnostic platform

Purpose

The methods (IHC/FISH) typically used to assess ER, PR, HER2, and Ki67 in FFPE specimens from breast cancer patients are difficult to set up, perform, and standardize for use in low and middle-income countries. Use of an automated diagnostic platform (GeneXpert®) and assay (Xpert® Breast Cancer STRAT4) that employs RT-qPCR to quantitate ESR1, PGR, ERBB2, and MKi67 mRNAs from formalin-fixed, paraffin-embedded (FFPE) tissues facilitates analyses in less than 3 h. This study compares breast cancer biomarker analyses using an RT-qPCR-based platform with analyses using standard IHC and FISH for assessment of the same biomarkers.

Methods

FFPE tissue sections from 523 patients were sent to a College of American Pathologists-certified central reference laboratory to evaluate concordance between IHC/FISH and STRAT4 using the laboratory’s standard of care methods. A subset of 155 FFPE specimens was tested for concordance with STRAT4 using different IHC antibodies and scoring methods.

Results

Concordance between STRAT4 and IHC was 97.8% for ESR1, 90.4% for PGR, 93.3% for ERBB2 (IHC/FISH for HER2), and 78.6% for MKi67. Receiver operating characteristic curve (ROC) area under the curve (AUC) values of 0.99, 0.95, 0.99, and 0.85 were generated for ESR1, PGR, ERBB2, and MKi67, respectively. Minor variabilities were observed depending on the IHC antibody comparator used.

Conclusion

Evaluation of breast cancer biomarker status by STRAT4 was highly concordant with central IHC/FISH in this blinded, retrospectively analyzed collection of samples. STRAT4 may provide a means to cost-effectively generate standardized diagnostic results for breast cancer patients in low- and middle-income countries.

Electronic supplementary material

The online version of this article (10.1007/s10549-018-4889-5) contains supplementary material, which is available to authorized users.

Reactive astrocytic S1P3 signaling modulates the blood-tumor barrier in brain metastases

Brain metastases are devastating complications of cancer. The blood-brain barrier (BBB), which protects the normal brain, morphs into an inadequately characterized blood-tumor barrier (BTB) when brain metastases form, and is surrounded by a neuroinflammatory response. These structures contribute to poor therapeutic efficacy by limiting drug uptake. Here, we report that experimental breast cancer brain metastases of low- and high permeability to a dextran dye exhibit distinct microenvironmental gene expression patterns. Astrocytic sphingosine-1 phosphate receptor 3 (S1P3) is upregulated in the neuroinflammatory response of the highly permeable lesions, and is expressed in patients' brain metastases. S1P3 inhibition functionally tightens the BTB in vitro and in vivo. S1P3 mediates its effects on BTB permeability through astrocytic secretion of IL-6 and CCL2, which relaxes endothelial cell adhesion. Tumor cell overexpression of S1P3 mimics this pathway, enhancing IL-6 and CCL-2 production and elevating BTB permeability. In conclusion, neuroinflammatory astrocytic S1P3 modulates BTB permeability.

Tyrosine kinase inhibitors for brain metastases in HER2-positive breast cancer

Approximately 30-50% of advanced HER2-positive breast cancer patients will develop central nervous system (CNS) metastases, with an annual risk of around 10%, and a half of them will die from brain progression. An increased risk of brain metastases is also seen in patients with early HER2-positive breast cancer administered curative therapy. Brain metastases in HER2-positive breast cancer patients usually constitute the first site of recurrence. The administration of anti-HER2 monoclonal antibodies, trastuzumab and pertuzumab, considerably delays the onset of symptomatic brain disease: however, the limited penetration of these compounds into the CNS hinders their efficacy. The small-molecule tyrosine kinase inhibitors of epidermal growth factor receptors family have established activity in HER2-positive breast cancer in both advanced disease and neoadjuvant setting. Favorable physico-chemical properties of these compounds allow them for a more efficient penetration through the blood-brain barrier, and hold the promise for more effective prevention and treatment of brain metastases. In this article we review the role of currently available or investigational HER2 tyrosine kinase inhibitors: lapatinib, neratinib, afatinib and tucatinib in the treatment of brain metastases in HER2-positive breast cancer patients.

Abstract P1-01-01: The blood-Tumor barrier as a therapeutic target to improve therapy of brain metastases of breast cancer

Objectives: Brain metastases of breast cancer demonstrate low and heterogeneous levels of permeability to drugs in mouse models and human craniotomies. The Blood-Brain Barrier (BBB), the protective lining of CNS blood vessels, impedes drug entry into the normal brain. When a metastasis forms, the BBB is locally altered to a poorly characterized Blood-Tumor Barrier (BTB). Quantitative experimental models indicate that most brain metastases have increased permeability over the normal BBB, but BTB permeability is both heterogeneous and ˜2 logs less than that of systemic metastases. We have interrogated three hematogenous models of brain metastasis of breast cancer to ask (1) whether the BTB is an ordered structure or a random breakdown of the BBB; (2) among brain metastases, whether consistent differences underlie the BTBs of lesions with low- and high permeabilities to fluorescent markers and drugs; (3) if alterations in BTB composition can functionally change its permeability. Our long term goal is to enhance uptake of drugs into brain metastases to effective levels.

Results: When uninvolved brain was compared with any brain metastasis, alterations in endothelial, pericytic, astrocytic, and microglial components of the BBB were observed. Both the pericyte and astrocyte components of the BTB were consistently altered with increased permeability: When metastases with relatively low and high permeability were compared, increased expression of a desmin+ subpopulation of pericytes was associated with higher permeability (231-BR6 P=0.0002; JIMT-1-BR3 P = 0.004; SUM190-BR3 P=0.008). A trend toward reduced CD13+ pericytes was observed in highly permeable metastases (231-BR6 P =0.014; JIMT-1-BR3 P =0.002, SUM190-BR3, NS). For GFAP+ astrocytes in the neuroinflammatory response surrounding metastases, no overall difference in cell number was observed between low and high permeability lesions. However, gene expression profiling of laser capture microdissected low and high permeabililty lesions demonstrated overexpression of the sphingosine-1 phosphate receptor 3 (S1P3) in the astrocytes of highly permeable lesions, which was confirmed at the protein expression level in all three models (231-BR6 P=0.034; JIMT-1-BR3 P = 0.01; SUM190-BR3 P=0.016). Inhibition of S1P3 via S1PR3 shRNA or a selective antagonist (TY-52156) functionally tightened the BTB in an in vitro model. Administration of TY-52156 to mice harboring 231-BR6 brain metastases had no effect on metastasis number, but decreased uptake of Texas Red Dextran dye into metastases (P=0.016). S1P3 mediated its effects on BTB permeability through astrocytic secretion of IL-6 and CCL2, which altered endothelial expression and localization of adhesive proteins, a potentially translatable pathway. Both desmin+ pericytes and S1P3+ astrocytes are present in human craniotomy specimens.

Conclusions: These experiments demonstrate that the BTB is a structure with consistent properties, and that further consistent changes underlie the transition from a low to high permeability BTB. While proof of principle, S1P3 inhibition studies indicate that the BTB permeability can be functionally modulated in vivo.

Citation Format: Steeg PS, Lyle TR, Paranjapee A, Lockman PR, Duchnowska R, Brastianos PK, Peer C, Figg WD, Pauly GT, Schneider JP, Smith QR, Gril B. The blood-Tumor barrier as a therapeutic target to improve therapy of brain metastases of breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-01-01.

Predictive value of quantitative HER2, HER3 and p95HER2 levels in HER2-positive advanced breast cancer patients treated with lapatinib following progression on trastuzumab

Lapatinib is a HER1 and HER2 tyrosine kinase inhibitor (TKI) approved in second line treatment of advanced or metastatic breast cancer following progression on trastuzumab-containing therapy. Biomarkers for activity of lapatinib and other TKIs are lacking. Formalin-fixed, paraffin-embedded primary tumor samples were obtained from 189 HER2-positive patients treated with lapatinib plus capecitabine following progression on trastuzumab. The HERmark® Breast Cancer Assay was used to quantify HER2 protein expression. HER3 and p95HER2 protein expression was quantified using the VeraTag® technology. Overall survival (OS) was inversely correlated with HER2 (HR = 1.9/log; P = 0.009) for patients with tumors above the cut-off positivity level by the HERmark assay. OS was significantly shorter for those with above median HER2 levels (HR = 1.7; P = 0.015) and trended shorter for those below the cut-off level of positivity by the HERmark assay (HR = 1.7; P = 0.057) compared to cases with moderate HER2 overexpression. The relationship between HER2 protein expression and OS was best captured with a U-shaped parabolic function (P = 0.004), with the best prognosis at moderate levels of HER2 protein overexpression. In a multivariate model including HER2, increasing p95HER2 expression was associated with longer OS (HR = 0.35/log; P = 0.027). Continuous HER3 did not significantly correlate with OS. Patients with moderately overexpressed HER2 levels and high p95HER2 expression may have best outcomes while receiving lapatinib following progression on trastuzumab. Further study is warranted to explore the predictive utility of quantitative HER2 and p95HER2 in guiding HER2-directed therapies.

Severe acute toxicity following gemcitabine administration: A report of four cases with cytidine deaminase polymorphisms evaluation

Gemcitabine (GCB) is a pyrimidine antimetabolite widely used in various solid tumors as a single agent or as a component of multidrug regimens. In the majority of patients, GCB is well tolerated, however life-threatening complications occasionally occur. The current report presents four cases of severe acute toxicity, which included two that were fatal, following administration of GCB alone or in combination with cisplatin. Of the four cases, in one, a Naranjo Adverse Drug Reaction Probability Score was definite, in two, probable and in one possible. To determine the potential causes of these toxicities, polymorphic variants of cytidine deaminase, the primary enzyme involved in the hepatic metabolism of GCB, were assessed. The homogeneous c.435TT variant was detected in one patient and a heterozygotic c.435CT variant in two, one of whom additionally harbored a heterozygotic c.79AC variant.

Abstract 4330: Astrocytic S1P3 regulates blood-brain/tumor barrier permeability

Introduction: Incidence of breast cancer brain metastasis is increasing owing to prolonged life-span and better detection techniques. Prognosis of patients with brain metastases is extremely poor with median survival time of one year. One of the major impediments in treating brain metastases is presence of blood-brain/tumor barrier that limits the permeability of chemotherapeutic drugs into the brain parenchyma. Understanding the mechanisms that regulate blood-brain/tumor barrier permeability in context of brain metastases is imperative to developing successful therapy.

Methods: Mouse models with brain-tropic sublines of MDA-MB-231 (231), JIMT-1, and SUM190 were used to generate breast cancer brain metastases. Using laser capture microscopy, the permeable and non-permeable lesions from mouse brains were isolated and profiled for gene expression using microarray. Immortalized human brain endothelial cells, astrocytes, and pericytes were used for developing in vitro blood-brain/tumor barrier model along with spheres generated with 231-BR6 or JIMT-1-BR3 cells. Secreted cytokines were evaluated using human cytokine profiler. Transendothelial electrical resistance (TEER) was measured using EVOM2 volt/ohm meter.

Results: Gene expression profiling and immunostaining of mouse brains, harboring breast cancer metastases showed that astrocytes at permeable regions express elevated S1P3. Pharmacological inhibition of S1P3 using antagonist TY-52156 (10mg/kg) in mice bearing 231-BR6 brain metastases showed reduction in 3KDa Texas red dextran (TRD) uptake. To investigate the role of S1P3 in regulating barrier permeability, we established in vitro blood-brain/tumor barrier models. Treatment of astrocytes with TY-52156 (2μM) significantly increased mean TEER values (33.9 to 55.8 Ω.cm2; p&lt;0.001, after 24 hrs), while there was a decrease in permeability for TRD (1.9 fold; p&lt;0.0001) and doxorubicin (1.3 folds; p&lt;0.05). Immunostaining on endothelial monolayer showed increased membranous ZO-1 and VE-cadherin expression. The dynamics of increase in TEER was faster when 231-BR6 spheres were included. We observed similar results when S1P3 was knocked down using shRNA. Astrocytes with down-modulated S1P3 showed decreased secretion of various cytokines including IL-6, IL-8, CCL2, CXCL1, and GM-CSF. Inhibition of these cytokines individually using neutralizing antibodies recapitulated the effects of S1P3 inhibition, while treatment of endothelial monolayer with activated cytokines increased the permeability. This study provides a proof of concept for role of S1P3 and downstream cytokine signaling in regulating blood-brain/tumor barrier permeability in breast cancer brain metastases.

Conclusion: Our study shows that astrocytic S1P3 regulates blood-brain/tumor barrier permeability in breast cancer brain metastases by modulating cytokine secretion. This observation might lead to discovery of novel strategies for augmenting drug efficacy.

Citation Format: Anurag N. Paranjape, Brunilde Gril, Stephan Woditschka, Emily Hua, Jeffrey C. Hanson, Xiaolin Wu, Renata Duchnowska, Priscilla K. Brastianos, David L. Liewehr, Seth M. Steinberg, Cody Peer, William D. Figg, Gary T. Pauly, Christina Robinson, Joel P. Schneider, Patricia S. Steeg. Astrocytic S1P3 regulates blood-brain/tumor barrier permeability [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4330. doi:10.1158/1538-7445.AM2017-4330

Abstract 4933: Desmin+pericyte subpopulations correlated with blood-tumor barrier permeability in brain metastases of breast cancer

Breast cancer brain metastases remain incurable. The blood-brain barrier (BBB) is a multicellular dynamic structure regulating exchanges between the blood and the central nervous system. As cancer cells colonize the brain, the BBB evolves into a blood-tumor barrier (BTB). The BTB limits compound penetration and therefore contributes to poor efficacy of chemotherapy. While the BBB has been well characterized in developmental and neurodegenerative disease studies, the BTB composition remains unknown.

We have characterized the BTB in three model systems of brain metastasis of breast cancer developed in the laboratory: a triple negative (231-BR6), and two HER2 overexpressing (SUM190-BR3, JIMT-1-BR3) subtypes. Using Texas Red dextran (TRD) as a marker of permeability and quantitative immunofluorescence staining, we analyzed the cellular and molecular composition of: 1) unaltered BBB vs. BTB, and 2) BTB in highly permeable metastases vs. BTB in poorly permeable metastases.

The BTB developed from the BBB in a series of alterations, including a neuroinflammatory reaction with astrogliosis, endothelial cell dilation, increased VEGF, reduced astrocyte endfoot polarity, and decrease in PDGFR+ pericytes. Only 10% of the metastatic lesions harbored a profound TRD exudation, which correlated with paclitaxel efficacy. We hypothesized that specific cellular and molecular changes account for the heterogeneity and increase in TRD diffusion. When metastases with relatively low- and high-TRD diffusion were compared, highly permeable metastases correlated with an increased expression of desmin+ pericytes in three models (231-BR6 p=0.0002; JIMT-1-BR3 p=0.004; SUM190-BR3 p=0.008) and a decrease in CD13+ pericytes in two model systems (231-BR6 p=0.014; JIMT-1-BR3 p=0.002). Decreased expression of laminin α2 in the parenchymal basement membrane (231-BR6 p=0.001; JIMT-1-BR3 p=0.049; SUM190-BR3 p=0.023) were associated with higher permeability. Desmin+ pericytes have been associated with pathological conditions such as fibrosis and spinal cord injury. Seven over nine human craniotomy specimens were positive for Desmin staining, validating clinically the relevance of our findings. We subsequently hypothesized that the desmin+ pericyte subpopulation functionally contributes to increased permeability. Desmin+ pericytes were produced in vitro by co-culturing primary mouse pericytes with astrocytes. When desmin+ or CD13+ pericytes were added to in vitro transendothelial electrical resistance (TEER) models of the BBB, the desmin+ pericytes exhibited less resistance, indicative of higher permeability.  The data suggest that desmin+ pericytes may facilitate the permeability of the BTB. These studies show that the BTB in brain metastasis model systems involves consistent molecular changes. These data may identify new strategies to selectively permeabilize the BTB and enhance chemotherapeutic efficacy.

Citation Format: Brunilde Gril, L. Tiffany Lyle, Paul R. Lockman, Chris E. Adkins, Afroz Shareef Mohammad, Emily Sechrest, Emily Hua, Diane Palmieri, David J. Liewehr, Seth M. Steinberg, Wojciech Kloc, Ewa Izycka-Swieszewska, Renata Duchnowska, Nayyar Naema, Priscilla K. Brastianos, Patricia S. Steeg. Desmin+pericyte subpopulations correlated with blood-tumor barrier permeability in brain metastases of breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4933. doi:10.1158/1538-7445.AM2017-4933

Abstract P1-03-03: High concordance of ER, PR, HER2 and Ki67 by central IHC and FISH with mRNA measurements by GeneXpert® breast cancer stratifier assay

Current methods for the assessment of ER, PR, Her2, and Ki67 using FFPE tissues are hard to standardize and difficult to perform in Low and Middle Income Countries (LMIC). The GeneXpert® breast cancer stratifier assay (RUO) (BC Strat) is a cartridge-based, RT-qPCR assay of ESR1, PGR, ERBB2, and MKi67 mRNAs using FFPE specimens. The assay is fast (&lt;2 hours, including &lt;10 minutes of hands-on time) and easy to perform.

The aims of this study were: 1) to evaluate the concordance of BC Strat using different IHC antibodies and scoring methods in a preliminary dataset (Part I); and 2) to assess concordance between BC Strat and high quality standard methods in an expanded dataset (Part II).

Methods

Part I: IHC Antibody Variability

To assess BC Strat concordance with various IHC antibodies, 155 invasive ductal carcinoma blocks were sourced from 3 sites. Twenty-four adjacent slide sections from each block were prepared and shipped to different labs for BC Strat analysis(Cepheid) or IHC and FISH testing. Table 1 summarizes the IHC antibodies and scoring methods used in each reference lab.

Table 1:IHC antibodies and scoring methods used in reference labs Antibody for IHClabIHC scoringERSP1MPLNAutomated (Aperio)ER6F11Path IncAutomated (Aperio)ER6F11USCManualPRIE2MPLNAutomated (Aperio)PR16Path IncAutomated (Aperio)PRPGR636USCManualHer2*4B5MPLNAutomated (Aperio)Her2*HercepTestUSCManualKi6730-9MPLNAutomated (Aperio)Ki67MIB1Path IncAutomated (Aperio)Ki67MIB1USCManual*HER2 FISH (all with PathVysion kit) was performed at USC

Part II: Concordance Study

522 invasive ductal carcinoma FFPE samples were sourced from 5 sites. All BC Strat analysis was performed at Cepheid and all IHC and FISH was performed in the Press laboratory at USC. Overall percent agreement (OPA), positive percent agreement (PPA), and negative percent agreement (NPA) between BC Strat and IHC were determined.

Results

Part I: IHC Antibody Variability

Table 2 summarizes the OPA for BC Strat analysis and IHC performed with different IHC antibodies and scoring methods. Slightly better concordance for ER and PR was observed between the BC Strat and the IHC methods performed at USC. Discordant IHC results were also observed among the reference labs' standard methodologies.

Table 2: Overall Percent Agreement between IHC and BC Strat Reference LabOPA with BC StratERMPLN92%ERPath Inc96%ERUSC98%PRMPLN84%PRPath Inc83%PRUSC87%Her2*MPLN*93%Her2*USC*91%Ki67MPLN75%Ki67Path Inc67%Ki67USC81%*for IHC 2+(equivocal), FISH HER2/CEP17 ratio was examined

Part II: Concordance Study

Of the 522 samples tested, 499 (96%) yielded valid results for both BC Strat and IHC (IHC and FISH for Her2). OPA between BC Strat and IHC was 98% for ESR1, 91% for PGR, 93% for ERBB2 (IHC and FISH, 97% for Her2 IHC excluding IHC2+), and 81% for MKi67.

Conclusion

BC Strat assay measurements for ESR1, PGR, ERBB2 and MKi67 mRNA expression in FFPE breast tumor tissues are highly concordant with IHC and FISH performed by high quality reference labs. Further investigations using clinical outcomes from independent studies including prospective-retrospective clinical trials are in progress.

Citation Format: Wu NC, Wong W, Ho KE, Chu VC, Rizo A, Davonport S, Kelly D, Makar R, Jassem J, Duchnowska R, Biernat W, Radecka B, Fujita T, Klein JL, Stonecypher M, Ohta S, Juhl H, Weidler JM, Bates M, Press MF. High concordance of ER, PR, HER2 and Ki67 by central IHC and FISH with mRNA measurements by GeneXpert® breast cancer stratifier assay [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-03-03.

Abstract P2-05-21: Predictive value of quantitative HER2 and HER3 levels combined with downstream signaling markers in HER2-positive advanced breast cancer patients treated with lapatinib

Background: Clinical correlates of lapatinib resistance have not been well defined. Previous studies implicated genes regulated by the estrogen receptor (ER) and activation or mutation of proteins downstream from HER family receptors. In the current study, HER2 and HER3 expression levels were quantitatively measured using a VeraTag® fluorescence-based assay, in addition to seven downstream signaling proteins determined by IHC. All biomarkers were correlated with overall survival (OS) in patients treated with lapatinib.

Methods: Formalin-fixed, paraffin-embedded samples were obtained from the primary tumor of 191 patients treated with lapatinib plus capecitabine following progression on trastuzumab. The HERmark® Breast Cancer Assay (Monogram Biosciences, South San Francisco) was used to quantify HER2 protein expression levels. HER3 protein expression was quantified using the VeraTag® technology (Monogram Biosciences). Expression of ER, PTEN, Cyclin E, HIF-2alpha, p-p70S6K, p-AMPK and p-MAPK were determined by IHC (Duchnowska et al., Oncotarget 2016; 7:550). OS analyses of HER2 and HER3 were stratified by key clinical variables, including stage and presence of a brain metastasis prior to lapatinib-based therapy.

Results: Among the downstream signaling molecules, HIF-2alpha (r = -0.23; p = 0.047) and ER (r = -0.27; p = 0.005) were negatively correlated with HER2 expression after adjustment for multiple testing. PTEN appeared to correlate with HER3, but was not significant after adjustment for multiple testing. OS was significantly shorter for both those below the cut-off level of positivity by the HERmark assay (HR = 1.8; p = 0.029), and those with above median HER2 levels (HR = 1.7; p = 0.009), as compared to cases with in between levels. The relationship between HER2 and OS is also captured by a U-shaped, parabolic function in HER2 (p = 0.005). Elevated HER3 showed a trend toward a correlation with longer OS (HR = 0.66/log; p = 0.16), somewhat stronger in the ER-negative subset (HR = 0.55/log; p = 0.085) and in the subset with above-median HER2 (0.48/log; p = 0.10), where inhibiting HER2 activation of HER3 may be more important. In multivariate Cox models, HER2 (parabola, intermediate HER2 best, p = 0.001), presence of brain metastases (HR = 2; p &lt; 0.001), ER (HR = 0.60; p = 0.009) and either p-p70S6K (HR = 0.66; p = 0.018) or p-AMPK (HR = 0.67; p = 0.022) were significantly associated with OS (p-p70S6K and p-AMPK were mutually correlated).

Conclusions: Patients with moderately increased HER2 levels may have best outcomes while receiving lapatinib following progression on trastuzumab. This supports recent findings of a less benefit from lapatinib in patients with high HER2 expression (Nunciforo et al., SABCS 2015, P3-07-08). HER3 levels do not seem to substantially impact the prognosis. Further studies are warranted to explore the predictive utility of quantitative HER2 and HER3 in guiding HER2-directed therapies.

Citation Format: Duchnowska R, Sperinde J, Czartoryska-Arlukowicz B, Mysliwiec P, Winslow J, Radecka B, Petropoulos C, Demlova R, Orlikowska M, Kowalczyk A, Lang I, Ziólkowska B, Debska-Szmich S, Merdalska M, Grela-Wojewoda A, Zawrocki A, Biernat W, Huang W, Jassem J. Predictive value of quantitative HER2 and HER3 levels combined with downstream signaling markers in HER2-positive advanced breast cancer patients treated with lapatinib [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-05-21.

Immunohistochemical prediction of lapatinib efficacy in advanced HER2-positive breast cancer patients

Molecular mechanisms of lapatinib resistance in breast cancer are not well understood. The aim of this study was to correlate expression of selected proteins involved in ErbB family signaling pathways with clinical efficacy of lapatinib. Study group included 270 HER2-positive advanced breast cancer patients treated with lapatinib and capecitabine. Immunohistochemical expression of phosphorylated adenosine monophosphate-activated protein (p-AMPK), mitogen-activated protein kinase (p-MAPK), phospho (p)-p70S6K, cyclin E, phosphatase and tensin homolog were analyzed in primary breast cancer samples. The best discriminative value for progression-free survival (PFS) was established for each biomarker and subjected to multivariate analysis. At least one biomarker was determined in 199 patients. Expression of p-p70S6K was independently associated with longer (HR 0.45; 95% CI: 0.25–0.81; p = 0.009), and cyclin E with shorter PFS (HR 1.83; 95% CI: 1.06–3.14; p = 0.029). Expression of p-MAPK (HR 1.61; 95% CI 1.13–2.29; p = 0.009) and cyclin E (HR 2.99; 95% CI: 1.29–6.94; p = 0.011) was correlated with shorter, and expression of estrogen receptor (HR 0.65; 95% CI 0.43–0.98; p = 0.041) with longer overall survival. Expression of p-AMPK negatively impacted response to treatment (HR 3.31; 95% CI 1.48–7.44; p = 0.004) and disease control (HR 3.07; 95% CI 1.25–7.58; p = 0.015). In conclusion: the efficacy of lapatinib seems to be associated with the activity of downstream signaling pathways – AMPK/mTOR and Ras/Raf/MAPK. Further research is warranted to assess the clinical utility of these data and to determine a potential role of combining lapatinib with MAPK pathway inhibitors.

Brain Metastasis Prediction by Transcriptomic Profiling in Triple-Negative Breast Cancer

BACKGROUND

Triple-negative breast cancer (TNBC) lacks expression of steroid hormone receptors (estrogen receptor α and progesterone) and epidermal growth factor receptor type 2. This phenotype shows high metastatic potential, with particular predilection to lungs and brain. Determination of TNBC transcriptomic profiles associated with high risk of brain metastasis (BM) might identify patients requiring alternative, more aggressive, or specific preventive and therapeutic approaches.

PATIENTS AND METHODS

Using a cDNA-mediated annealing, selection, extension, and ligation assay, we investigated expression of 29,369 gene transcripts in primary TNBC tumor samples from 119 patients-71 in discovery cohort A and 48 in independent cohort B-that included best discriminating genes. Expression of mRNA was correlated with the occurrence of symptomatic BM.

RESULTS

In cohort A, the difference at the noncorrected P < .005 was found for 64 transcripts (P = .23 for global test), but none showed significant difference at a preset level of false-discovery rate of < 10%. Of the 30 transcripts with the largest differences between patients with and without BM in cohort A, none was significantly associated with BM in cohort B.

CONCLUSION

Analysis based on the primary tumor gene transcripts alone is unlikely to predict BM development in advanced TNBC. Despite its negative findings, the study adds to the knowledge on the biology of TNBC and paves the way for future projects using more advanced molecular assays.

Alterations in Pericyte Subpopulations Are Associated with Elevated Blood-Tumor Barrier Permeability in Experimental Brain Metastasis of Breast Cancer

PURPOSE

The blood-brain barrier (BBB) is modified to a blood-tumor barrier (BTB) as a brain metastasis develops from breast or other cancers. We (i) quantified the permeability of experimental brain metastases, (ii) determined the composition of the BTB, and (iii) identified which elements of the BTB distinguished metastases of lower permeability from those with higher permeability.

EXPERIMENTAL DESIGN

A SUM190-BR3 experimental inflammatory breast cancer brain metastasis subline was established. Experimental brain metastases from this model system and two previously reported models (triple-negative MDA-231-BR6, HER2⁺ JIMT-1-BR3) were serially sectioned; low- and high-permeability lesions were identified with systemic 3-kDa Texas Red dextran dye. Adjoining sections were used for quantitative immunofluorescence to known BBB and neuroinflammatory components. One-sample comparisons against a hypothesized value of one were performed with the Wilcoxon signed-rank test.

RESULTS

When uninvolved brain was compared with any brain metastasis, alterations in endothelial, pericytic, astrocytic, and microglial components were observed. When metastases with relatively low and high permeability were compared, increased expression of a desmin⁺ subpopulation of pericytes was associated with higher permeability (231-BR6 P = 0.0002; JIMT-1-BR3 P = 0.004; SUM190-BR3 P = 0.008); desmin⁺ pericytes were also identified in human craniotomy specimens. Trends of reduced CD13⁺ pericytes (231-BR6 P = 0.014; JIMT-1-BR3 P = 0.002, SUM190-BR3, NS) and laminin α2 (231-BR6 P = 0.001; JIMT-1-BR3 P = 0.049; SUM190-BR3 P = 0.023) were also observed with increased permeability.

CONCLUSIONS

We provide the first account of the composition of the BTB in experimental brain metastasis. Desmin⁺ pericytes and laminin α2 are potential targets for the development of novel approaches to increase chemotherapeutic efficacy. Clin Cancer Res; 22(21); 5287-99. ©2016 AACR.

Immune response in breast cancer brain metastases and their microenvironment: the role of the PD-1/PD-L axis

BACKGROUND

A better understanding of immune response in breast cancer brain metastases (BCBM) may prompt new preventive and therapeutic strategies.

METHODS

Immunohistochemical expression of stromal tumor-infiltrating lymphocytes (TILs: CD4, CD8, CTLA4), macrophage/microglial cells (CD68), programmed cell death protein 1 receptor (PD-1), programmed cell death protein 1 receptor ligand (PD-L)1, PD-L2 and glial fibrillary acid protein was assessed in 84 BCBM and their microenvironment.

RESULTS

Median survival after BCBM excision was 18.3 months (range 0-99). Median number of CD4+, CD8+ TILs and CD68+ was 49, 69 and 76 per 1 mm(2), respectively. PD-L1 and PD-L2 expression in BCBM was present in 53 % and 36 % of cases, and was not related to BCBM phenotype. PD-1 expression on TILs correlated positively with CD4+ and CD8+ TILs (r = 0.26 and 0.33), and so did CD68+ (r = 0.23 and 0.27, respectively). In the multivariate analysis, survival after BCBM excision positively correlated with PD-1 expression on TILs (hazard ratio (HR) = 0.3, P = 0.003), CD68+ infiltration (HR = 0.2, P < 0.001), brain radiotherapy (HR = 0.1, P < 0.001), endocrine therapy (HR = 0.1, P < 0.001), and negatively with hormone-receptor-negative/human epidermal growth factor receptor 2 (HER2)-positive phenotype of primary tumor (HR = 2.6, P = 0.01), HER2 expression in BCBM (HR = 4.9, P = 0.01).

CONCLUSIONS

PD-L1 and PD-L2 expression is a common occurrence in BCBM, irrespective of primary tumor and BCBM phenotype. Favorable prognostic impact of PD-1 expression on TILs suggests a beneficial effect of preexisting immunity and implies a potential therapeutic role of immune checkpoint inhibitors in BCBM.

Problems of diagnostic assessment in advanced pancreatic neuroendocrine neoplasm and treatment implications: a case report and literature review

We are reporting a case of a 55-year-old woman who was diagnosed as having a non-functioning pancreatic neuroendocrine neoplasm (NF-PNEN), the World Health Organization (WHO) low grade (G1) with liver metastases. In the staging process the positron emission tomography - computed tomography with Fluorine-18-Fluorodeoxyglucose (F-FDG PET-CT) and spiral CT then the gallium-DOTA-octreotate positron emission tomography - computer tomography (⁶⁸Ga-DOTATATE PET-CT) shown difference in burden of disease. In first line therapy, everolimus (Afinitor®, Novartis Pharma GmbH, Germany) at the oral dose of 10 mg once daily and octreotide long-acting release (Sandostatin LAR®) 30 mg i.m. every 4 weeks were administered. Then, due to disease progression - radioisotope therapy with b-emitter Yttrium-90 (⁹⁰Y). Based on this experience and on the review of the literature, we recommend that the discrepancy between the imaging studies could be due to heterogeneity of proliferation rate and somatostatin receptors (SSTR) expression within a primary PNEN and metastases. Therefore in such cases of advanced PNEN WHO G1 in the lack of response to everolimus and octreotide LAR administration isotope therapy without a prior chemotherapy should be considered as a palliative treatment according to ESMO Clinical Practice Guidelines and Polish Network of Neuroendocrine Tumors.

Immunohistochemical Predictors of Bone Metastases in Breast Cancer Patients

Bones are the most common metastatic site of relapse in breast cancer patients and the prediction of bone metastases (BM) risk might prompt developing preventive and therapeutic strategies. The aim of the study was to correlate imumohistochemical (IHC) expression of selected proteins in primary breast cancer with the occurrence of BM. We analyzed expression of proteins potentially associated with BM in primary tumors of 184 patients with metastatic breast cancer (113 with- and 71 without BM). Expression of estrogen receptor (ER) in primary tumor was more common in patients with- compared to those without BM (74 vs. 45 % respectively, p = 0.0001), whereas in this subset less common was expression of parathyroid hormone related protein receptor type 1 (16 vs. 34 %, respectively, p = 0.007) and cytoplasmic expression of osteopontin (OPNcyt; 1.9 vs. 14 %, respectively, p = 0.002). The relationship between expression of ER and OPNcyt and the occurrence of BM was confirmed in the multivariate analysis. The ER-positive/OPNcyt negative phenotype was significantly more common in patients with- compared to those without BM (75 and 25 %, p < 0.0001, respectively; HR 1.79, p = 0.013). Luminal A (43 vs. 23 % respectively, p = 0.009) and luminal B/HER2-positive (16 vs. 4.9 % respectively, p = 0.032) subtypes were more common in patients with- compared to those without BM, whereas triple negative breast cancer subtype was less common (16 vs. 38 %, p = 0.002).

Quantitative HER2 and p95HER2 levels in primary breast cancers and matched brain metastases

BACKGROUND

Patients with advanced breast cancer positive for human epidermal growth factor receptor 2 (HER2) are at high risk for brain metastasis (BM). The prevalence and significance of expression of HER2 and its truncated form p95HER2 (p95) in BM is unknown.

METHODS

Seventy-five pairs of formalin-fixed paraffin-embedded samples from matched primary breast cancers (PBCs) and BM were assayed for quantitative p95 and HER2-total (H2T) protein expression using the p95 VeraTag and HERmark assays, respectively.

RESULTS

There was a net increase in p95 and H2T expression in BM relative to the matched PBC (median 1.5-fold, P = .0007 and 2.1-fold, P < .0001, respectively). Cases with H2T-positive tumors were more likely to have the largest (≥5-fold) increase in p95 (odds ratio = 6.3, P = .018). P95 positivity in PBC correlated with progression-free survival (hazard ratio [HR] = 2.2, P = .013), trended with shorter time to BM (HR = 1.8, P = .070), and correlated with overall survival (HR = 2.1, P = .042). P95 positivity in BM correlated with time to BM (HR = 2.0, P = .016) but did not correlate with overall survival from the time of BM diagnosis (HR = 1.2, P = .61).

CONCLUSIONS

This is the first study of quantitative p95 and HER2 expression in matched PBC and BM. BM of breast cancer shows significant increases in expression of both biomarkers compared with matched PBC. These data provide a rationale for future correlative studies on p95 and HER2 levels in BM.

Recurrent pyoderma gangrenosum precipitated by breast cancer: a case report and review of the literature

INTRODUCTION

Pyoderma gangrenosum is a rare clinical entity of poorly understood pathogenesis, characterized by rapidly progressing skin necrosis. In around half of patients pyoderma gangrenosum is a manifestation of underlying systemic diseases, such as rheumatoid arthritis, inflammatory bowel disease or myeloproliferative disorders. There have been very few reports on the association of pyoderma gangrenosum with solid malignancies.

CASE PRESENTATION

We report a case of a 68-year-old Caucasian woman in whom pyoderma gangrenosum first appeared around 30 years earlier, at the time of exacerbation of rheumatoid arthritis, and recurred as a manifestation of locally advanced breast cancer. The causative role of the neoplastic process was partly confirmed by the healing of the skin ulceration only following effective endocrine cancer therapy, whereas earlier attempts with standard anti-inflammatory therapy were unsuccessful.

CONCLUSIONS

Pyoderma gangrenosum has a recurrent nature and may be reactivated by various causes within several years. Therefore, a prompt and thorough diagnosis accompanied by treatment of the underlying disease is necessary.

DNA double-strand break repair genes and oxidative damage in brain metastasis of breast cancer

BACKGROUND

Breast cancer frequently metastasizes to the brain, colonizing a neuro-inflammatory microenvironment. The molecular pathways facilitating this colonization remain poorly understood.

METHODS

Expression profiling of 23 matched sets of human resected brain metastases and primary breast tumors by two-sided paired t test was performed to identify brain metastasis-specific genes. The implicated DNA repair genes BARD1 and RAD51 were modulated in human (MDA-MB-231-BR) and murine (4T1-BR) brain-tropic breast cancer cell lines by lentiviral transduction of cDNA or short hairpin RNA (shRNA) coding sequences. Their functional contribution to brain metastasis development was evaluated in mouse xenograft models (n = 10 mice per group).

RESULTS

Human brain metastases overexpressed BARD1 and RAD51 compared with either matched primary tumors (1.74-fold, P < .001; 1.46-fold, P < .001, respectively) or unlinked systemic metastases (1.49-fold, P = .01; 1.44-fold, P = .008, respectively). Overexpression of either gene in MDA-MB-231-BR cells increased brain metastases by threefold to fourfold after intracardiac injections, but not lung metastases upon tail-vein injections. In 4T1-BR cells, shRNA-mediated RAD51 knockdown reduced brain metastases by 2.5-fold without affecting lung metastasis development. In vitro, BARD1- and RAD51-overexpressing cells showed reduced genomic instability but only exhibited growth and colonization phenotypes upon DNA damage induction. Reactive oxygen species were present in tumor cells and elevated in the metastatic neuro-inflammatory microenvironment and could provide an endogenous source of genotoxic stress. Tempol, a brain-permeable oxygen radical scavenger suppressed brain metastasis promotion induced by BARD1 and RAD51 overexpression.

CONCLUSIONS

BARD1 and RAD51 are frequently overexpressed in brain metastases from breast cancer and may constitute a mechanism to overcome reactive oxygen species-mediated genotoxic stress in the metastatic brain.

Metastasis-Initiating Cells in Renal Cancer

Metastasis is a complex process that propagates cells from the primary or initial site of the cancer occurrence to distant parts of the body. Cancer cells break from the cancer site and circulate through the bloodstream or lymph vessels, allowing them to reach nearly all parts of the body. These circulating tumour cells (CTCs) contain specialized metastasis-initiating cells (MICs) that reside in the biological heterogeneous primary tumour. Researchers have hypothesized that metastasis of renal cell carcinoma is initiated by circulation of MICs in patients’ blood and bone marrow. Based on the cancer stem/progenitor cell concept of carcinogenesis, understanding the molecular phenotypes of metastasis-initiating cells (MICs) in renal cancer could play a vital role in developing strategies for therapeutic interventions in renal cancer. Existence of MICs among CTCs in renal carcinoma has not been proven in large scale. However, some studies have reported that specialized markers are found on the surface of circulating cells from the primary tumour. In mice, MICs have been isolated from CTCs using such markers, which have then been transplanted into xenograft model to show whether they give rise to metastasis in different organs. Considering these findings, in this review we have attempted to summarize the studies connected with MICs and their gene expression profiles that are responsible for metastasis in renal cancer.

Quantitative measurements of tumoral p95HER2 protein expression in metastatic breast cancer patients treated with trastuzumab: independent validation of the p95HER2 clinical cutoff

PURPOSE

P95HER2 (p95) is a truncated form of the HER2, which lacks the trastuzumab-binding site and contains a hyperactive kinase domain. Previously, an optimal clinical cutoff of p95 expression for progression-free survival (PFS) and overall survival (OS) was defined using a quantitative VeraTag assay (Monogram Biosciences) in a training set of trastuzumab-treated metastatic breast cancer (MBC) patients.

EXPERIMENTAL DESIGN

In the current study, the predictive value of the p95 VeraTag assay cutoff established in the training set was retrospectively validated for PFS and OS in an independent series of 240 trastuzumab-treated MBC patients from multiple institutions.

RESULTS

In the subset of 190 tumors assessed as HER2-total (H2T)-positive using the quantitative HERmark assay (Monogram Biosciences), p95 VeraTag values above the predefined cutoff correlated with shorter PFS (HR = 1.43; P = 0.039) and shorter OS (HR = 1.94; P = 0.0055) where both outcomes were stratified by hormone receptor status and tumor grade. High p95 expression correlated with shorter PFS (HR = 2.41; P = 0.0003) and OS (HR = 2.57; P = 0.0025) in the hormone receptor-positive subgroup of patients (N = 78), but not in the hormone receptor-negative group. In contrast with the quantitative p95 VeraTag measurements, p95 immunohistochemical expression using the same antibody was not significantly correlated with outcomes.

CONCLUSIONS

The consistency in the p95 VeraTag cutoff across different cohorts of patients with MBC treated with trastuzumab justifies additional studies using blinded analyses in larger series of patients.

Profound prevention of experimental brain metastases of breast cancer by temozolomide in an MGMT-dependent manner

PURPOSE

Brain metastases of breast cancer cause neurocognitive damage and are incurable. We evaluated a role for temozolomide in the prevention of brain metastases of breast cancer in experimental brain metastasis models.

EXPERIMENTAL DESIGN

Temozolomide was administered in mice following earlier injection of brain-tropic HER2-positive JIMT-1-BR3 and triple-negative 231-BR-EGFP sublines, the latter with and without expression of O(6)-methylguanine-DNA methyltransferase (MGMT). In addition, the percentage of MGMT-positive tumor cells in 62 patient-matched sets of breast cancer primary tumors and resected brain metastases was determined immunohistochemically.

RESULTS

Temozolomide, when dosed at 50, 25, 10, or 5 mg/kg, 5 days per week, beginning 3 days after inoculation, completely prevented the formation of experimental brain metastases from MGMT-negative 231-BR-EGFP cells. At a 1 mg/kg dose, temozolomide prevented 68% of large brain metastases, and was ineffective at a dose of 0.5 mg/kg. When the 50 mg/kg dose was administered beginning on days 18 or 24, temozolomide efficacy was reduced or absent. Temozolomide was ineffective at preventing brain metastases in MGMT-transduced 231-BR-EGFP and MGMT-expressing JIMT-1-BR3 sublines. In 62 patient-matched sets of primary breast tumors and resected brain metastases, 43.5% of the specimens had concordant low MGMT expression, whereas in another 14.5% of sets high MGMT staining in the primary tumor corresponded with low staining in the brain metastasis.

CONCLUSIONS

Temozolomide profoundly prevented the outgrowth of experimental brain metastases of breast cancer in an MGMT-dependent manner. These data provide compelling rationale for investigating the preventive efficacy of temozolomide in a clinical setting.

Abstract P6-11-07: Quantitative p95HER2 levels in primary breast cancers and in matched brain metastases

Background: Patients with HER2-positive breast cancer are at high risk for brain metastases. A large number of HER2-positive tumors also express p95HER2 (p95), a truncated form of HER2 that lacks the trastuzumab binding site but retains kinase activity. Although p95 expression in primary breast tumors is well studied, the prevalence and significance of p95 expression in brain metastases is unknown. In the current study we examined expression of p95 in brain metastases and in matched primary breast tumors.

Methods: Seventy-five pairs of formalin-fixed paraffin-embedded samples from matched primary breast cancers and brain metastases were assayed for quantitative p95 protein expression using the p95 VeraTag® assay (Clin Cancer Res, 16:4226, 2010) specific for the M611 form of p95. Sufficient material to obtain p95 data in both primary and matched brain metastasis samples was available in 52 cases. In the remaining 23 cases, a p95 measurement was obtained in either the primary or brain metastasis sample. Estrogen (ER) and progesterone (PR) receptor status were scored using immunohistochemistry. Hormone receptor positivity was defined as either ER or PR positive. Quantitative HER2 protein expression was measured using the HERmark® assay. Both the p95 VeraTag assay and the HERmark assay measure tumor-averaged protein expression in units of relative fluorescence per mm2 tumor (RF/mm2). Measurements of p95 &gt; 2.8 RF/mm2 and HER2 &gt; 17.8 RF/mm2 were considered as positive results.

Results: There was a net increase in p95 expression in brain metastases relative to the matched primary tumor with a median increase of 1.5-fold (p = 0.001, range 0.2-fold to 35-fold). The increase in p95 expression was only weakly correlated with the increase in quantitative HER2 expression (R2 = 0.18; p = 0.0018). Cases with HERmark-positive tumors were more likely to have the largest (≥ 5-fold) increase in p95 expression compared to those with lower HER2 expression (odds ratio = 6.3; p = 0.018). Changes in p95 levels from primary to brain metastasis were unrelated to hormone receptor status (p = 0.59). P95 positivity in the primary tumor correlated with time from breast cancer diagnosis to first progression (HR = 2.2; p = 0.012) when stratified by hormone receptor status and tumor grade. Although there was a trend towards correlation of p95 positivity in the brain metastasis with time from diagnosis to brain metastasis (HR = 1.7; p = 0.058, stratified as above), p95 positivity did not correlate with overall survival from the time of brain metastasis diagnosis (HR = 1.3; p = 0.42, stratified as above).

Conclusions: This is the first study of quantitative p95 expression in matched primary tumors and brain metastases. Brain metastases of breast cancer show significant increases in p95 protein expression compared to matched primary tumors. These data provide a rationale for future correlative studies on p95 levels in brain metastases.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-11-07.

Abstract P6-11-04: Profound prevention of experimental brain metastases of breast cancer by temozolomide in a MGMT-dependent manner

Purpose: Brain metastases of breast cancer cause neurocognitive damage and are incurable. We evaluated in experimental brain metastasis model a role of temozolomide, an oral brain permeable alkylating agent characterized by significant uptake in the central nervous system, in the prevention of brain metastases of breast cancer.

Material and methods: To assess preventive role of temozolomide, mice were inoculated with 175,000 triple-negative 231-BR-EGFP cells in 0.1 mL PBS in the left ventricle of the heart. Three days after tumor cell inoculation, mice were randomized to temozolomide at the dose of 50 mg/kg delivered by oral gavage in saline, 5 days a week for 4 weeks, or vehicle. Subsequent experiments used temozolomide doses of 25, 10, 5, 1 and 0.5 mg/kg. To evaluate the efficacy of temozolomide in treating established BM, mice received temozolomide (50 mg/kg) beginning on either day 18 or day 24 post-injection of 231-BR-EGFR cells, 5 days a week for two and one week, respectively. To investigate the impact of temozolomide on survival, mice injected with 231-BR-EGFP cells were randomized to vehicle, temozolomide on days 3-14, or temozolomide on days 17-28 post-injection, per the schedule described above. To determine the functional contribution of MGMT expression in the BM preventive model, similar experiments were performed using 231-BR-EGFP cells with induced MGMT expression, and MGMT-positive Jimt-1 cells. Metastases were counted in step sections of one hemisphere of each brain. Additionally, the percentage of MGMT-positive tumor cells in 62 patient-matched sets of breast cancer primary tumors and resected brain metastases was determined immunohistochemically.

Results: Temozolomide, when dosed at 50, 25, 10 or 5 mg/kg, 5 days/week, beginning 3 days after inoculation, completely prevented the formation of experimental brain metastases from MGMT-negative 231-BR-EGFP cell line. At a 1 mg/kg dose, temozolomide prevented 68% of large brain metastases, and was ineffective at a dose of 0.5 mg/kg. When the 50 mg/kg dose was administered beginning on days 18 or 24, temozolomide efficacy was reduced or absent. Both schedules of temozolomide (days 3-14 and days 17-28) significantly increased survival (P = .0003 by long-rank test). Earlier administration of temozolomide resulted in long term survival of 6 and 2 out of 10 mice, respectively; a significant difference compared to vehicle (P &lt; .0001 and .0003, respectively).Temozolomide was ineffective at preventing brain metastases in the MGMT-positive 231-BR-EGFP and Jimt-BR3 sublines. In 62 patient-matched sets of primary breast tumors and resected brain metastases 43.5% of the specimens had concordant low MGMT expression, while in another 14.5% sets high MGMT staining in the primary tumor corresponded with low staining in the brain metastasis.

Conclusions: Temozolomide profoundly prevents the outgrowth of experimental brain metastases of breast cancer in a MGMT-dependent manner. The majority of patients had low MGMT expressing brain metastases. These data provide a compelling rationale for investigating preventive efficacy of temozolomide in high-risk advanced breast cancer patients.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P6-11-04.

Immunohistochemical prediction of brain metastases in patients with advanced breast cancer: the role of Rad51

BACKGROUND

There are no clinically useful biomarkers predictive of brain metastases (BM) in breast cancer. In this study, we investigated the correlation between expression of selected proteins in the primary tumor and the risk of BM in patients with metastatic breast cancer (MBC).

METHODS

The study included 198 MBC patients (96 with and 102 without BM). Using tissue microarrays derived from the primary tumor, we assessed by immunohistochemical expression of ER, PR, HER2, Ki-67, CK5/6, EGFR, HER3, CXCR4, Rad51, E-cadherin, and claudin 3 and 4.

RESULTS

Ki-67 ≥14% (hazard ratio [HR] 2.76; P < 0.001), cytoplasmic expression of Rad51 (HR 1.87; P = 0.014) and ER-negativity (HR 1.72; P = 0.029) were associated with increased risk of BM in the multivariate analysis. A three-biomarker profile including ER, Ki-67 and Rad51 vs. other subtypes combined yielded an HR of 4.43 (P < 0.001).

CONCLUSIONS

ER-negativity, cytoplasmic expression of Rad51 and high Ki-67 are associated with increased risk of BM.