Clinical characteristics with inflammation profiling of long COVID and association with 1-year recovery following hospitalisation in the UK: a prospective observational study

BACKGROUND

No effective pharmacological or non-pharmacological interventions exist for patients with long COVID. We aimed to describe recovery 1 year after hospital discharge for COVID-19, identify factors associated with patient-perceived recovery, and identify potential therapeutic targets by describing the underlying inflammatory profiles of the previously described recovery clusters at 5 months after hospital discharge.

METHODS

The Post-hospitalisation COVID-19 study (PHOSP-COVID) is a prospective, longitudinal cohort study recruiting adults (aged ≥18 years) discharged from hospital with COVID-19 across the UK. Recovery was assessed using patient-reported outcome measures, physical performance, and organ function at 5 months and 1 year after hospital discharge, and stratified by both patient-perceived recovery and recovery cluster. Hierarchical logistic regression modelling was performed for patient-perceived recovery at 1 year. Cluster analysis was done using the clustering large applications k-medoids approach using clinical outcomes at 5 months. Inflammatory protein profiling was analysed from plasma at the 5-month visit. This study is registered on the ISRCTN Registry, ISRCTN10980107, and recruitment is ongoing.

FINDINGS

2320 participants discharged from hospital between March 7, 2020, and April 18, 2021, were assessed at 5 months after discharge and 807 (32·7%) participants completed both the 5-month and 1-year visits. 279 (35·6%) of these 807 patients were women and 505 (64·4%) were men, with a mean age of 58·7 (SD 12·5) years, and 224 (27·8%) had received invasive mechanical ventilation (WHO class 7-9). The proportion of patients reporting full recovery was unchanged between 5 months (501 [25·5%] of 1965) and 1 year (232 [28·9%] of 804). Factors associated with being less likely to report full recovery at 1 year were female sex (odds ratio 0·68 [95% CI 0·46-0·99]), obesity (0·50 [0·34-0·74]) and invasive mechanical ventilation (0·42 [0·23-0·76]). Cluster analysis (n=1636) corroborated the previously reported four clusters: very severe, severe, moderate with cognitive impairment, and mild, relating to the severity of physical health, mental health, and cognitive impairment at 5 months. We found increased inflammatory mediators of tissue damage and repair in both the very severe and the moderate with cognitive impairment clusters compared with the mild cluster, including IL-6 concentration, which was increased in both comparisons (n=626 participants). We found a substantial deficit in median EQ-5D-5L utility index from before COVID-19 (retrospective assessment; 0·88 [IQR 0·74-1·00]), at 5 months (0·74 [0·64-0·88]) to 1 year (0·75 [0·62-0·88]), with minimal improvements across all outcome measures at 1 year after discharge in the whole cohort and within each of the four clusters.

INTERPRETATION

The sequelae of a hospital admission with COVID-19 were substantial 1 year after discharge across a range of health domains, with the minority in our cohort feeling fully recovered. Patient-perceived health-related quality of life was reduced at 1 year compared with before hospital admission. Systematic inflammation and obesity are potential treatable traits that warrant further investigation in clinical trials.

FUNDING

UK Research and Innovation and National Institute for Health Research.

Association of clinical outcomes in metastatic breast cancer patients with circulating tumour cell and circulating cell-free DNA

BACKGROUND

Both circulating tumour cell (CTC) and total circulating cell-free DNA (ccfDNA) predict cancer patient prognosis. However, no study has explored the prognostic value of the combined use of CTC and ccfDNA. We aimed to investigate individual and joint effects of CTC and ccfDNA on clinical outcomes of metastatic breast cancer (MBC) patients.

METHODS

We collected 227 blood samples from 117 MBC patients. CTCs were enumerated using the CellSearch System. ccfDNAs were quantified by quantitative real-time polymerase chain reaction and Qubit fluorometer. The individual and joint effects of CTC and ccfDNA levels on patient progression-free survival (PFS) and overall survival (OS) were analysed using Cox proportional hazards models.

RESULTS

Compared to patients with <5 CTCs, patients with ≥5 CTCs had a 2.58-fold increased risk of progression and 3.63-fold increased risk of death. High level of ccfDNA was associated with a 2.05-fold increased risk of progression and 3.56-fold increased risk of death. These associations remained significant after adjusting for other important clinical covariates and CTC/ccfDNA levels. CTC and ccfDNA levels had a joint effect on patient outcomes. Compared to patients with low levels of both CTC and ccfDNA, those with high levels of both markers exhibited a >17-fold increased death risk (P < 0.001). Moreover, longitudinal analysis of 132 samples from 22 patients suggested that the inconsistency between CTC level and outcome in some patients could possibly be explained by ccfDNA level.

CONCLUSIONS

CTC and total ccfDNA levels were individually and jointly associated with PFS and OS in MBC patients.

Detection of Activating Estrogen Receptor Gene (ESR1) Mutations in Single Circulating Tumor Cells

Purpose: Early detection is essential for treatment plans before onset of metastatic disease. Our purpose was to demonstrate feasibility to detect and monitor estrogen receptor 1 (ESR1) gene mutations at the single circulating tumor cell (CTC) level in metastatic breast cancer (MBC).Experimental Design: We used a CTC molecular characterization approach to investigate heterogeneity of 14 hotspot mutations in ESR1 and their correlation with endocrine resistance. Combining the CellSearch and DEPArray technologies allowed recovery of 71 single CTCs and 12 WBC from 3 ER-positive MBC patients. Forty CTCs and 12 WBC were subjected to whole genome amplification by MALBAC and Sanger sequencing.Results: Among 3 selected patients, 2 had an ESR1 mutation (Y537). One showed two different ESR1 variants in a single CTC and another showed loss of heterozygosity. All mutations were detected in matched cell-free DNA (cfDNA). Furthermore, one had 2 serial blood samples analyzed and showed changes in both cfDNA and CTCs with emergence of mutations in ESR1 (Y537S and T570I), which has not been reported previously.Conclusions: CTCs are easily accessible biomarkers to monitor and better personalize management of patients with previously demonstrated ER-MBC who are progressing on endocrine therapy. We showed that single CTC analysis can yield important information on clonal heterogeneity and can be a source of discovery of novel and potential driver mutations. Finally, we also validate a workflow for liquid biopsy that will facilitate early detection of ESR1 mutations, the emergence of endocrine resistance and the choice of further target therapy. Clin Cancer Res; 23(20); 6086-93. ©2017 AACR.

Abstract P1-01-05: Prognostic values of circulating tumor cells (CTC) and cancer associated macrophage-like cells (CAML) enumerations in metastatic breast cancer: The role for innate immunity in the metastatic process

Background: The enumeration of circulating tumor cells (CTCs) using the CellSearch assay is a well-established prognostic and predictive marker for metastatic breast cancer (MBC). However, additional prognostic markers are lacking in patients with ≥ 5 CTCs in 7.5 ml of blood. Tumor-associated macrophages (TAMs) are derived from circulating monocytes or tissue-resident macrophages. TAMs have a controversial role in metastasis and anti-tumor processes. Recent studies showed that circulating cancer associated macrophage-like cells (CAMLs) are specialized phagocytic myeloid cells and found in the peripheral blood of patients with solid tumors including breast cancer, but not in healthy individuals. The presence of CAMLs may indicate the activation of innate immunity in cancer patients. The function and prognostic value of CAMLs in MBC is unknown. In the current study, we measured CTCs and CAMLs on the CellSearch™ platform and investigated their prognostic values in MBC.

Methods: Peripheral blood samples from 127 stages IV breast cancer patients were collected at baseline before starting first-line therapy. The detection and enumeration of CTCs and CAMLs in 7.5 ml blood sample were performed on the CellSearch™ system. CTCs were identified by cytokeratins (CK-8, 18, and 19) positive and CD45 negative staining. CAMLs were defined by positive staining for cytokeratins and CD45 (Adams et al, PNAS, 111(9):3514-9, 2014). CTCs and CAMLs enumeration in associations with the progression-free survival (PFS) and overall survival (OS) of patients were evaluated using Kaplan Meier curves and Cox proportional hazards modeling.

Results: The image review of CAMLs by using CellSearch analysis showed heterogeneous morphological phenotypes. CAMLs are large cells presenting enlarged nuclei or multiple individual nuclei, and both cytokeratin and CD45 positive with diffused cytoplasmic staining. Among the 127 MBC patients, 38 (29.9%) had elevated CTCs (≥5 CTCs), and 21 (16.5%) had at least one CAML detected. Patients with CAMLs had a significantly increased PFS (p=0.0374) and OS (p=0.0042), compared to patients without CAMLs at baseline. Patients with elevated baseline CTCs and CAMLs had worse PFS with a hazard ratio (HR) of 4.04 (95% CI 2.16 -7.56, P&lt;0.0001), compared to patients with &lt; 5 CTCs and without CAMLs. The combined analysis of baseline CTCs enumeration and CAMLs showed similar effect on patient OS. Compared to patients with &lt; 5 CTCs and without CAMLs, patients with &lt; 5 CTCs and with CAMLs, patients with ≥ 5 CTCs and without CAMLs, and patients with ≥ 5 CTCs and with CAMLs, had an increasing trend of death risk, with an HR of 2.66 (95% CI 0.53-13.21), 6.14 (2.10-17.92), and 9.13 (3.05-27.37), respectively (p for trend&lt;0.0001).

Conclusion: Baseline enumerations of both individual CTCs and CAMLs are feasible and increase our ability to accurately predict outcome in MBC patients. Evaluation of CAMLs in peripheral blood may be a marker of innate immunity and provide additional prognostic values for MBC.

Citation Format: Mu Z, Wang C, Ye Z, Rossi G, Austin L, Yang H, Cristofanilli M. Prognostic values of circulating tumor cells (CTC) and cancer associated macrophage-like cells (CAML) enumerations in metastatic breast cancer: The role for innate immunity in the metastatic process [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 P1-01-05.

Detection and Characterization of Circulating Tumor Associated Cells in Metastatic Breast Cancer

The availability of blood-based diagnostic testing using a non-invasive technique holds promise for real-time monitoring of disease progression and treatment selection. Circulating tumor cells (CTCs) have been used as a prognostic biomarker for the metastatic breast cancer (MBC). The molecular characterization of CTCs is fundamental to the phenotypic identification of malignant cells and description of the relevant genetic alterations that may change according to disease progression and therapy resistance. However, the molecular characterization of CTCs remains a challenge because of the rarity and heterogeneity of CTCs and technological difficulties in the enrichment, isolation and molecular characterization of CTCs. In this pilot study, we evaluated circulating tumor associated cells in one blood draw by size exclusion technology and cytological analysis. Among 30 prospectively enrolled MBC patients, CTCs, circulating tumor cell clusters (CTC clusters), CTCs of epithelial-mesenchymal transition (EMT) and cancer associated macrophage-like cells (CAMLs) were detected and analyzed. For molecular characterization of CTCs, size-exclusion method for CTC enrichment was tested in combination with DEPArray™ technology, which allows the recovery of single CTCs or pools of CTCs as a pure CTC sample for mutation analysis. Genomic mutations of TP53 and ESR1 were analyzed by targeted sequencing on isolated 7 CTCs from a patient with MBC. The results of genomic analysis showed heterozygous TP53 R248W mutation from one single CTC and pools of three CTCs, and homozygous TP53 R248W mutation from one single CTC and pools of two CTCs. Wild-type ESR1 was detected in the same isolated CTCs. The results of this study reveal that size-exclusion method can be used to enrich and identify circulating tumor associated cells, and enriched CTCs were characterized for genetic alterations in MBC patients, respectively.

Abstract 172: Managing metastatic breast cancer via serial monitoring with circulating cell-free tumor DNA next generation sequencing testing

Background: Metastatic breast cancer (MBC) is an incurable disease with complex molecular features including somatic mutations that evolve in relation to genomic instability and selective treatment pressure. Patients with treatment-refractory MBC may benefit from tumor genomic evaluation using next generation sequencing (NGS). Furthermore, analysis of circulating tumor DNA (ctDNA) in patients with advanced disease offers the possibility of non-invasive molecular monitoring.

Methods: A patient with MBC was tested at each progression with a ctDNA NGS panel (Guardant360™) that includes all NCCN-recommended somatic genomic variants for solid tumors and sequences complete exons of &gt;50 genes to report single nucleotide variants (SNVs), fusions, amplifications, and indels with high sensitivity and ultra-high specificity (&gt;99.9999%). The patient was diagnosed with invasive breast cancer at age 44 and treated with surgery and hormonal therapy. At age 61, she had axillary adenopathy and liver metastases. Treatment details are in Table 1.

Results: ctDNA analysis was performed at the time of metastatic diagnosis and at 5 additional time points over the course of treatment. All samples revealed an ERBB2 exon 19 indel (p.Leu755_Glu757delinsSer), and multiple SNVs and gene amplifications. ERBB2 amplification was seen in 4 of 6 samples. Mutant allele fractions (Table 1) correlated with clinical response to treatment and progression.

Conclusions: Analysis of ctDNA in this patient identified an ERBB2 exon 19 indel, which are present in 2-4% of non-small cell lung cancers but 1-2% in breast cancer. Treatment with anti-HER2 monoclonal antibody or dual anti-EGFR/ERBB2 tyrosine kinase inhibitor therapies may show clinical benefit. ctDNA analysis can detect emergence of actionable resistance mutations with the advantage of serial evaluation, allowing capture of inter- and intra-tumor heterogeneity and illustration of molecular progression and response. Table 1.Blood DrawDisease status at time of blood drawMutant allele fraction of ERBB2 indel (* = ERBB2 amplification)Treatment1Initial diagnosis9%trastuzumab, pertuzumab and docetaxel (TPD), cycle 12Stable disease1%*TPD cycle 23Progressing10%*TPD cycle 34Progressing62%*trastuzumab, emtansine (TDM1) 3 cycles5Progressing70%*vinorelbine, trastuzumab, everolimus6Partial response1%flourouracil, epirubicin, cyclophoasphamide

Citation Format: Laura Austin, Rebecca Nagy, Oliver Zill, Richard B. Lanman, AmirAli Talasaz, Massimo Cristofanilli. Managing metastatic breast cancer via serial monitoring with circulating cell-free tumor DNA next generation sequencing testing. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 172.

Abstract P6-18-01: Novel genetic susceptibility loci for inflammatory breast cancer identified by whole exome sequencing

Background: Inflammatory breast cancer (IBC) is an extremely aggressive form of locally advanced breast cancer that affects approximately 5% of breast cancer patients. The prognosis of IBC patients is remarkably poor, with a three-year survival rate of approximately 30% compared to 60% for non-IBC breast cancer patients. The etiology of IBC is largely unknown. A few risk factors have been reported such as body mass index (BMI) and educational level. Prior evidence has also implicated genetic components in IBC etiology. For instance, the reported familial cases and racial incidence disparity of IBC patients, as well as the fact IBC patients typically have a younger age onset than non-IBC patients, all indicated the possible involvement of genetic factors. Nevertheless, as yet no genetic epidemiological study has been reported to evaluate IBC genetic predisposition.

Methods: To test the hypothesis that genetic variants and mutations may affect IBC susceptibility, we performed whole exome sequencing in a pilot case-control study that contained 70 IBC cases and 119 unrelated cancer-free controls. Sequencing data were de-multiplexed, filtered, assessed for various quality control metrics, mapped to reference genome and annotated. Comprehensive single variant-based, gene-centered, and pathway-based analyses were conducted to identify variants, genes, and pathways that may be involved in IBC predisposition.

Results: We obtained &gt; 50x on-target sequencing coverage of the whole exome in &gt; 90% of the patients. In single variant analysis, we identified six variants reaching genome-wide significance. Four variants were encoded by genes that have been implicated in breast cancer development including MALAT1, MAP3K9, POLR3B, and FIP1L1. Two variants were encoded by novel genes that have not been related to breast cancer, including CCDC30 and LINC01565. Two types of analyses based on a gene-centered strategy identified top genes such as SLC39A4, CDHR1, AP5Z1, GNB3, ITGA10, etc. However, possibly due to the limited sample size, none of these genes reached genome-wide significance. Ingenuity Pathway Analysis (IPA), using the complete list of significant genes identified by each of these analyses all reported "cancer" as the highest possible disorder associated with these genes, demonstrating the biological plausibility of our findings. Moreover, canonical pathways such as IL4 signaling, glycogen degradation, epithelial adherence junction signaling, and CCR3 signaling in eosinophils were among the top pathways that were found involved in IBC predisposition.

Conclusion: Overall, we provided novel preliminary evidence that genetic variants are potentially associated with the risk of developing IBC. We are currently conducting validation studies with larger sample sizes are warranted to confirm these findings and identify additional genetic susceptibility loci.

Citation Format: Ye Z, Li B, Wang C, Zhong X, Wei Q, Mu Z, Austin L, Jaslow R, Avery T, Palazzo J, Biederman L, Yang H, Cristofanilli M, IBC Inflammatory Breast Cancer International Consortium. Novel genetic susceptibility loci for inflammatory breast cancer identified by whole exome sequencing. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-18-01.

Abstract P2-08-09: Prognostic values of circulating tumor cell (CTC) enumeration and their clusters in advanced breast cancer

Background The enumeration of circulating tumor cells (CTCs) has been proven to have prognostic values in several solid tumors including breast cancer. It has been established that a cut-off of 5 CTCs in 7.5 ml of blood may significantly differentiate breast cancer patients with favorable and unfavorable survival. However, CTC enumeration has not been shown to further predict the prognosis in those patients with more than 5 CTCs in 7.5 ml of blood. There are several recent in vitro and in vivo studies suggesting that clusters of CTC can be identified in blood and those clusters may play an important role in tumor progression and metastasis. Few clinical studies have been reported to enumerate CTC clusters and evaluate their prognostic values. In the current study, we hypothesize that the enumeration of CTC clusters play an important role in the prognostication of advanced breast cancer patients by providing additional predictive performance independent of CTC enumeration.

Methods In an ongoing study of blood-based breast cancer biomarkers, we enrolled 114 patients with stages III and IV breast cancer. Among them, 68 patients had inflammatory breast cancer (IBC), an extremely aggressive form of breast cancer with a much lower survival rate than non-IBC breast cancer patients. The number of single CTCs and CTC clusters (two or more CTCs bound together) in 7.5 ml blood sample were counted using the CellSearch™ system (Janssen Diagnostic) at baseline study entry, and their associations with the progression-free survival (PFS) of patients were evaluated using Kaplan Meier curves and Cox proportional hazards modeling.

Results Baseline CTCs were detected in 67 (58.77%) patients. Thirty-five (30.70%) and 19 patients (16.67%) had elevated CTCs (≥5 CTCs/7.5 mL) and clusters, respectively. IBC patients had a slightly higher percentage of cluster (17.65%) compared to non-IBC patients (15.22%). Patients with elevated baseline CTC and cluster had worse PFS (log rank P, 0.0009 and 0.0035, respectively). Compared to patients with &lt; 5 CTC and without cluster, those patients with elevated CTC without cluster, and those with elevated CTC with cluster had an increasingly higher risk of disease progression with an hazard ratio [HR] of 1.93 (95% confidence interval [CI] 1.01-3.67) and 2.91 (1.54-5.50), respectively (P for trend = 0.001). Moreover, the combined analysis of baseline CTC and cluster enumerations showed similar effect when the analysis was restricted to IBC patients (HR 3.03, 95% CI 1.34-6.86).

Conclusion Baseline enumerations of both individual CTCs and CTC clusters predict PFS in advanced stage breast cancer patients. CTC clusters provide further prognostic value in patients with elevated CTC and their molecular characterizations may provide novel insights into the metastasis process.

Citation Format: Ye Z, Mu Z, Wang C, Palazzo JP, Biederman L, Li B, Jaslow R, Avery T, Austin L, Yang H, Cristofanilli M. Prognostic values of circulating tumor cell (CTC) enumeration and their clusters in advanced breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-08-09.

Abstract P3-05-02: Detection of activating estrogen receptor 1 (ESR1) in circulating tumor DNA (ctDNA) in hormone-receptor positive metastatic breast cancer (MBC)

Background

About 65% of breast cancers express the estrogen receptor α and the mainstay of treatment are therapies that result in estrogen receptor modulation (selective estrogen receptor modulators, SERMs) or estrogen deprivation (aromatase inhibitors, AIs). Even though endocrine therapy has resulted in reduced recurrence and mortality, a significant portion of patients relapse with metastatic disease and subsequently progress while on therapy for advanced disease (endocrine resistance). Recent evidence showed that activating hot spot mutations in the ligand binding domain of the ERα (ESR1) are acquired on treatment (frequency of 20%) and can drive resistance to endocrine therapy, especially AIs. ESR1 mutations can be detected by evaluation of circulating tumor DNA (ctDNA), a method where circulating DNA fragments with tumor-specific sequence alterations are identified in the blood of patients.

Methods

This is a retrospective evaluation of 9 patients with hormone receptor positive (HR+) metastatic breast cancer (MBC) who had progressed on multiple lines of endocrine therapy (ET) and were found to have ESR1 mutations in ctDNA. Patients had blood drawn for ctDNA analysis either at progression to serve as a baseline before starting a new regimen or to monitor response to ongoing treatment. Guardant360™(Guardant Health) involves ctDNA isolation from plasma using a Qiagen circulating nucleic acid kit, then a panel of 68 gene mutations associated with solid tumors as reported in the COSMIC database sequenced using single-molecule digital sequencing technology.

Results

All of the patients had MBC and were luminal subtype except for one HER2+, and most had invasive ductal carcinoma although 2 patients were invasive lobular carcinoma (22%). Most patients had both bone and visceral involvement (78%), only two patients had bone only metastasis. The patients were generally heavily pretreated with an average of 3 lines of ETs and 6 lines of therapy altogether (chemotherapy + ET). Duration on endocrine therapy ranged from 23 months to 7 years (mean 4.3 years). All patients were found to have ESR1 mutations on ctDNA, the range of percentage of mutant allele was 0.28-23.76%. Three patients had tissue sent for NGS and none of the tissue samples had an ESR1 mutation detected although they were biopsied at various time points in treatment. One of those patients had two ESR1 mutations in ctDNA, which were not detected on tissue sent for NGS one year prior, and had not been on ET for several years. One patient with abdominal carcinomatosis from lobular carcinoma who had been on ETs therapies for 6 years was found to have 4 distinct ESR1 mutations in a single blood draw, suggesting sub-clonal evolution of resistance. One patient also had 5 circulating tumor cells, all of which had ESR1 mutations detected when circulating tumor cells were individually sequenced.

Conclusions

ctDNA is a sensitive test for detection of ESR1 in HR+ MBC patients, with the advantage of being a blood based assay which lends itself to serial analysis. In this patient population ctDNA can be a helpful tool to predict response to ET and predict treatment failure.

Citation Format: Austin L, Rodriguez A, Jaslow R, Fortina P, Nagy R, Zill O, Talasaz A, Cristofanilli M. Detection of activating estrogen receptor 1 (ESR1) in circulating tumor DNA (ctDNA) in hormone-receptor positive metastatic breast cancer (MBC). [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-05-02.

Abstract P2-02-14: Detection and characterization of CTCs isolated by ScreenCell®-Filtration in metastatic breast cancer

Background: Circulating Tumor cells (CTCs) detection has prognostic and predictive implications in patients with metastatic breast cancer (MBC). Genomic and phenotypic analysis of CTCs hold enormous promise as blood-based molecular characterization and monitoring disease progression and treatment benefit with a strong potential to be translated into more individualized targeted treatments. FDA-approved CellSearch™ detection allows only enumeration of CTCs expressing EpCAM without molecular characterization. CTCs represent very heterogeneous populations of tumorigenic cancer cells and some subpopulations have undergone epithelial-Mesenchymal transition (EMT), which is associated metastasis process and an unfavourable outcome. EpCAM-based enrichment technique has failed to detect EMT subpopulations due to the decreased expression or loss of epithelial markers. Non-EpCAM-based approaches are needed for identifying EMT CTCs. The ScreenCell® devices are single-use and low-cost innovative devices that use a filter for enrichment-free isolation of CTCs by a two-steps combining size-based separation and staining using different markers. The DEPArray™ system is the ideal downstream isolation system to collect single or pooled CTCs for molecular and genetic analysis. In this study, we evaluated the feasibility of achieving CTCs detection/enumeration using ScreenCell® filtration followed by single cell isolation with the DEPArray™ in MBC patients.

Methods: The first part of the study consisted in evaluating CTCs detection/enumeration in 30 patients with stage III and stage IV breast cancer. 3 mL of whole blood in an EDTA or Transfix tubes was collected and processed on the ScreenCell® Cyto device following the instructions of the supplier. CTCs were stained with cytokeratin (CK-8, 18, and 19), leukocyte antigen (CD45), and a nuclear dye (DAPI) and counted under fluorescence microscope. CTCs were identified as positive staining for CK and DAPI and negative staining for CD45 (CK+/DAPI+CD45-). In the second part, After enrichment, CTCs were stained with CK, CD45, and DAPI and sorted with DEPArray™ Platform (Silicon Biosystems, Inc). Single CTCs were collected and the DNA of each single CTCs was amplified with Ampli1™ WGA kit, and the genome integrity index (GII) was assessed by Ampli1™ QC kit (Silicon Biosystems, Inc). Library was constructed and whole exome sequencing (WES) of DNA mutations was conducted.

Results: Twenty patient samples had CTCs detected (66.7%), the number of CTCs was 1 to 347 per 3.0 ml of whole blood. CTC-clusters were detected in 7 patient samples (23.3%). Single CTCs were collected on DEPArray™ platform after enrichment with ScreenCell filtration. GII was confirmed with the presence of short, medium, and long DNA fragments (3 to 4 PCR bands) in the WGA library by PCR-based assay. All collected CTCs showed high GII as measured by Ampli1™ QC kit (GII ≥ 3) for WES of DNA mutations. The data analysis of WES results is under processing.

Conclusions: ScreenCell® filtration is simple and effective devices to isolate CTCs and identify CTC-clusters. Isolation of single cells for molecular analysis using the combination of ScreenCell® filtration and DEPArray™ Platform is feasible for genetic characterization of CTCs.

Citation Format: Mu Z, Benali-Furet N, Uzan G, Ye Z, Austin L, Wang C, Nguyen1 T, Avery T, Jaslow R, Yang H, Cristofanilli M. Detection and characterization of CTCs isolated by ScreenCell®-Filtration in metastatic breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-02-14.

Abstract P2-02-11: Detection of activating estrogen receptor 1 (ESR1) mutation on single circulating tumor cells from metastatic breast cancer patients

Background: 65% of primary breast cancers express the estrogen receptor α (ERα) and the mainstay of treatment are therapies that result in selective estrogen receptor modulation (SERM) of estrogen deprivation (aromatase inhibitors, AIs). Even thought endocrine therapy resulted in reduced recurrence and mortality, a significant portion of patients relapse with a metastatic disease and subsequently progress while of therapy for advanced disease (endocrine resistance). Recent evidence showed that activating hot spot mutation in the ligand binding domain of the ERα are acquired on treatment (frequency of 20%) and can drive resistance to endocrine therapy. Circulating tumor cells (CTCs) provide a non-invasive accessible source of tumor material and the molecular profiling of these rare cells might lead to insight on disease progression and therapeutic strategies. These features suggest that the detection of ESR1 mutation on single CTC may be a useful biomarker for therapy guidance.

Purpose: Investigate the incidence and heterogeneity of ESR1 mutational status within single CTCs isolated from individual metastatic breast cancer patients (mBCs), combining the FDA approved CellSearch® system for enumeration of CTCs with the DEPArrayTM technologies.

Methods: CTCs were enriched and enumerate by CellSearch® in 7.5 ml blood samples collected from 21 mBCs according to standard protocol. Each CTC-enriched sample with at least 20 CTCs was recovered from Veridex cartridge and loaded into the DEPArrayTM A300K chip, since the DEPArrayTM analyzed only the 66% of the sample volume loaded, according to the manufacturer's instructions. The chip scanning was performed by automated fluorescence microscope. The loaded cells were recovered as single cell and subdivided in tree different group: Cytokeratin (CK) positive ( Dapi+, CK+, ER-, CD45-); ER positive (Dapi+, ER+, CK+, CD45-); White Blood cells (WBCs) (Dapi+, CD45+, CK-, ER-). Single CTCs and WBCs were then submitted to whole genome amplification (WGA) using the Single Cell WGA kit (Yikon Genomics) according the manufacturer's instructions. Detection of target 14 ESR1 hot spot mutations was performed on ABI PRISM® 3700 genetic analyzer by target Sanger sequencing.

Results: 3 out of 21 mBCs with ≥20 CTCs were sorted and a total of 65 cells were recovered. WGA and ESR1 mutational status were performed on a total of 25 cells (respectively 11 ER+, 6 CK+ and 8 WBCs). In 1 of the 3 patients, that failed 2 lines of chemotherapy and previous single agent endocrine therapy, molecular heterogeneity was detected among its ER+ cells. 4 of 5 ER+ cells were heterozygote for the Y537S while one cell was homozygous, maybe due to a loss of heterozygosity. Y537S is one of the most common mutations that leads to a ligand independent ER transcriptional activity that does not respond to endocrine manipulation. No mutations were reported in all the CK+ and WBC cells analyzed.

Conclusions: This study demonstrates the feasibility of a non-invasive approach based on liquid biopsy in mBCs. Evaluation of ER status and early identification of ESR1 mutation in ER+ CTCs might allow to predict effect of the endocrine therapies and switching to other treatments before the emergence of metastatic disease.

Citation Format: Paolillo C, Mu Z, Austin L, Nguyen T, Capoluongo E, Fortina P, Cristofanilli M. Detection of activating estrogen receptor 1 (ESR1) mutation on single circulating tumor cells from metastatic breast cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-02-11.

Prospective assessment of the prognostic value of circulating tumor cells and their clusters in patients with advanced-stage breast cancer

The enumeration of circulating tumor cells (CTCs) provides important prognostic values in patients with metastatic breast cancer. Recent studies indicate that individual CTCs form clusters and these CTC-clusters play an important role in tumor metastasis. We aimed to assess whether quantification of CTC-clusters provides additional prognostic value over quantification of individual CTCs alone. In 115 prospectively enrolled advanced-stage (III and IV) breast cancer patients, CTCs and CTC-clusters were counted in 7.5 ml whole blood using the CellSearch system at baseline before first-line therapy. The individual and joint effects of CTC and CTC cluster counts on patients' progression-free survival (PFS) were analyzed using Cox proportional hazards modeling. Of the 115 patients, 36 (31.3 %) had elevated baseline CTCs (≥5 CTCs/7.5 ml) and 20 (17.4 %) had CTC-clusters (≥2 CTCs/7.5 ml). Patients with elevated CTCs and CTC-clusters both had worse PFS with a hazard ratio (HR) of 2.76 [95 % confidence interval (CI) 1.57-4.86, P log-rank = 0.0005] and 2.83 (1.48-5.39, P log-rank = 0.001), respectively. In joint analysis, compared with patients with <5 CTCs and without CTC-clusters, patients with elevated CTCs but without clusters, and patients with elevated CTCs and with clusters, had an increasing trend of progression risk, with an HR of 2.21 (1.02-4.78) and 3.32 (1.68-6.55), respectively (P log-rank = 0.0006, P trend = 0.0002). The additional prognostic value of CTC-clusters appeared to be more pronounced in patients with inflammatory breast cancer (IBC), the most aggressive form of breast cancer with the poorest survival. Baseline counts of both individual CTCs and CTC-clusters were associated with PFS in advanced-stage breast cancer patients. CTC-clusters might provide additional prognostic value compared with CTC enumeration alone, in patients with elevated CTCs.

Abstract 224: Enrichment and isolation of uncontaminated breast cancer cells from human blood samples

Cancer cells in peripheral blood, known as circulating tumor cells (CTCs), play an important role in tumor dissemination. CTCs are shed from either the primary tumor or its metastases and circulate in the peripheral blood of patients; thus they can be regarded as “liquid biopsies” of metastasizing cells. Although the exact origin and physiology of CTCs is unknown, a fraction of these cells are thought to be viable metastatic precursors capable of initiating a clonal metastatic lesion. The molecular characterization of CTCs is important because it may provide insights into the molecular biology of metastasis, the association of their molecular profiles with treatment outcomes, and reveal the presence of potential therapeutic targets. The process of CTC enrichment represents a significant step toward the isolation of CTCs from whole blood. Given that there are approximately 5×109 erythrocytes and 107 leukocytes per ml of whole blood, purification must represent a reduction of many orders of magnitude. In this study, we show a method to isolate CTCs which combines a microfluidic cell separation device (Parsortix system) as an enrichment method followed by the DEPArray selection system. The Parsortix system is versatile in its ability to separate, capture and harvest CTCs in an enriched form compatible with the needs of downstream processes such as DEPArray. Here we demonstrate enrichment of CTCs via the Parsortix system using both breast cancer cell spiked healthy blood donor samples and blood from metastatic breast cancer patients. For these experiments, two milliliters of blood were processed. The cells were harvested and stained to identify CTCs in the enriched harvest product. Cells were stained with fluorescently labeled monoclonal antibodies specific for pan cytokeratin (CK-8/18/19-PE), leukocyte common antigen (CD45-APC), and nuclear stained with [4′,6-diamidino-2-phenylindole (DAPI)]. With spiked samples, tumor cells were isolated by DEPArray selection, which yielded a pure population of tumor cells for molecular characterization. Tumor cells were defined by presence of a clear DAPI-stained nucleus, CK-PE-positive cytoplasm and CD-45-APC negative. We demonstrated that by using a combination of enrichment and isolation/selection methods, we are able to isolate single, uncontaminated tumor cells to achieve single cell molecular analysis. The use of single cells is emerging as a powerful approach to molecular analysis in oncology, and this study demonstrates its potential application with circulating tumor cells.

Citation Format: Sandra V. Fernandez, Christopher Wagner, Zahida Parveen, Lucy Aburto, Carmela Paolillo, George Hvichia, Zhaomei Mu, Laura Austin, Massimo Cristofanilli. Enrichment and isolation of uncontaminated breast cancer cells from human blood samples. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 224. doi:10.1158/1538-7445.AM2015-224

Abstract 2788: Comprehensive high-depth target sequencing in circulating tumor DNAs of patients with inflammatory and non-inflammation breast cancers

Inflammatory breast cancer (IBC) is an extremely aggressive form of locally advanced breast cancer that affects about 5% of breast cancer patients. The prognosis of IBC patients is remarkably poor, with a three-year survival rate of approximately 30% compared to 60% for patients with non-IBC breast cancers. These facts highlight the importance of accurate characterization, early detection, and timely treatment of IBC patients. Thus, it is important to develop novel and clinically applicable non-invasive biomarkers to characterize the unique presentation of IBC. In this study, we searched for somatic mutations in the circulating tumor DNAs (ctDNAs) that could be used to non-invasively characterize IBC patients and inform their clinical management. Using ctDNAs extracted from plasma of 10 pairs of IBC and non-IBC patients that were matched on major demographic and clinical variables, we conducted a high-depth target next-generation sequencing study that interrogated a comprehensive panel of 127 TCGA (The Cancer Genome Atlas)-reported cancer-related genes with &gt;7000 uniquely designed and validated probes. Overall, we obtained &gt;500x coverage in &gt;80% of the interrogated regions, and &gt;100x coverage in &gt;97% of the regions. We found that C&gt;T mutations predominated in well-reported mutated genes such as TP53, PIK3CA, EGFR, and CDH1. Compared to non-IBC patients, IBC patients appeared to have a higher percentage of mutations in PIK3CA but a lower percentage in TP53. Interestingly, about 78% of mutated genes that were only detected in IBC patients encode zinc finger-related proteins, a family of transcriptional factors that have been implicated in IBC development. In comparison, about 43% of genes that were detected only in non-IBC patients encode proteins important to cell division regulation. Furthermore, network-based stratification (NBS) analysis of the mutation profile revealed clusters of IBC relative to non-IBC samples, indicating the potential of mutation profiling in identifying molecularly distinct subtypes of IBC patients. Preliminary longitudinal analysis of ctDNAs from three patients with multiple plasma samples indicated that de novo mutations in important genes including PIK3CA, RB1, and KRAS appeared in patient blood after chemotherapy and/or targeted therapy treatments. Moreover, the emergence of some of these mutations was temporally correlated with the responses of patients to the treatments they received. Overall, this study provides novel evidence that ctDNA mutation status may help to non-invasively characterize IBC tumors, and might also serve as a novel non-invasive marker to monitor treatment efficacy and prognosis of breast cancer patients. Future studies with larger sample sizes are warranted to confirm our findings and identify additional clinically useful markers for the characterization and management of IBC and non-IBC patients.

Citation Format: Hushan Yang, Xue Zhong, Qiang Wei, Zhaomei Mu, Zhong Ye, Yinzhi Lai, Huei-Wen Lin, Rebecca Jaslow, Tiffany Avery, Laura Austin, Zhaohui Sun, Shengrong Lin, Grace Zhao, Ling Fang Tang, Ronald E. Myers, Juan P. Palazzo, Laura Biederman, Bingshan Li, Massimo Cristofanilli. Comprehensive high-depth target sequencing in circulating tumor DNAs of patients with inflammatory and non-inflammation breast cancers. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2788. doi:10.1158/1538-7445.AM2015-2788

Abstract P2-04-02: Identifying molecular targets and mechanisms of treatment resistance in inflammatory breast cancer (IBC) using reverse-phase protein microarrays (RPMA)

Background

Inflammatory Breast Cancer (IBC) is a clinicopathologic diagnosis characterized by rapid progression and poor prognosis. Even with the advent of targeted therapies and a multimodal approach, IBC is often treatment refractory and a therapeutic challenge for all subtypes, including ER+ and HER-2 amplified (HER2+) disease (Masuda et al). Therefore identifying mechanisms of resistance to molecularly targeted therapy could provide clues to improve management and outcome. Recent studies comparing the gene expression profiles of IBC tumors with non-IBC demonstrated that HER2+ IBC have increased mTOR signaling compared to their non-IBC counterparts (Iwamoto et al). mTOR activation is a mechanism for Trastuzumab resistance and may contribute to treatment resistance in HER2+ IBC. The availability of molecular diagnostics evaluating phosphoproteins is an appealing approach to predict treatment-sensitivity and select more effective combinations.

Methods

This is an observational analysis of 12 IBC patients who had tissue biopsy after progression on standard therapies including HER-2 targeted therapies. Tissue analysis for expression of cancer-related phosphoproteins was performed using TheraLink™. The TheraLink™ assay uses reverse-phase protein microarrays (RPMA) to quantify HER1, HER2, and HER3 receptor overexpression; it also evaluates for phosphorylation of the receptor which indicates activation. Phosphorylation of HER downstream signaling pathways such as JAK2, AKT/mTOR and MEK1/2 are also detected. Additionally, next generation sequencing (NGS) using FoundationOne™ was performed if sufficient tissue was available.

Results

All patients had IBC and most had metastatic disease (83%). According to subtype 25% of patients were ER+/HER2-, 42% ER+/HER2+, 25% ER-/HER2+, 8% ER-/HER2-. 58% of tumors demonstrated HER1 activation, 75% had HER2 activation and 58% had HER3 activation. Interestingly, 83% had mTOR activation, and most of these patients also had accumulation of its downstream proteins, S6 ribosomal protein and 4E-BP-1. 78% of patients with HER2 activation also had mTOR activation. Two of the 4 patients who were HER2- by IHC/FISH had HER2 activation by RPMA. Six patients also had NGS on tissue; 75% had concordance between HER2 activation on TheraLink™ and ERBB2 amplification on NGS, 67% had concordance with mTOR activation on TheraLink™ and mutation in the mTOR pathway (PIK3CA mutation or PTEN loss) on NGS. One patient with triple negative, chemo-refractory IBC who underwent 3 lines of neoadjuvant therapy prior to bilateral mastectomy was found to have HER1, HER2, HER3 and mTOR activation; she was started on lapatinib and capecitabine and remains with no recurrent disease and on treatment.

Conclusions

Patients with IBC often have activation of members of the HER family and mTOR pathway indicating molecular targets and potential mechanisms of resistance in IBC. The concomitant use of NGS and RPMA is an intriguing approach to molecular diagnostics in this aggressive and treatment refractory disease providing additional information on pathway activation leading to expanded therapeutic options. Future prospective studies should clarify the potential impact in treatment selection and outcome.

Citation Format: Laura Austin, Kimberly Limentani, Juan Palazzo, Tiffany Avery, Rebecca Jaslow, Ron Hencin, Emanuel F Petricoin, Massimo Cristofanilli. Identifying molecular targets and mechanisms of treatment resistance in inflammatory breast cancer (IBC) using reverse-phase protein microarrays (RPMA) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-04-02.

Abstract P4-01-11: Circulating tumor cells (CTCs) detect HER2+ status and phenotypic heterogeneity in metastatic breast cancer (MBC)

Background

Circulating tumor cells (CTCs) are epithelial cells that can be found circulating in the blood of MBC patients and may represent a heterogeneous population including epithelial cells and cancer stem cells (CSC) shed from the tumor. Their detection and enumeration has prognostic significance and can be used for longitudinal monitoring of response to treatment. Recent advances have allowed for the detection of HER2 protein expressing CTCs using the CellSearch™ platform. HER2 expression has been associated with CSCs phenotype in absence of gene amplification (Korkaya et al, Oncogene 2008) and particularly in Luminal B disease (Ithimakin et al, Cancer Res, 2014). We hypothesized that HER2+/CTCs are detectable in patients with MBC irrespective of their HER2 status and this information can be potentially be used for treatment selection. Targeting HER2+ CSCs may result in clinical benefit and improved outcome.

Methods

This is a prospective analysis of 40 patients with locally advanced or MBC whose blood was analyzed for the baseline detection of CTCs as part of their disease initial evaluation. Blood was drawn for CTC detection on eligible patients at initiation of a new line of therapy; CTCs monitoring was repeated at progression or change in therapy. The 7.5mL of whole blood was collected in a CellSave™ Preservative Tube, and CTC isolation, enumeration and characterization were performed using the FDA-approved CellSearch™ System (Janssen Diagnostics, USA). The CellSearch™ tumor phenotyping reagent HER-2/neu (Fluorescein-conjugated) was used to determine CTC with HER-2/neu expression using the CellTrack™ Analyzer II.

Results

Most patients in this study had metastatic disease (90%). According to disease subtype, 43% of patients were ER+/HER2- (Luminal A), 17% ER+/HER2+ (Luminal B), 20% ER-/HER2+ (HER2) and 20% ER-/HER2- (TNBC). Moreover, 55% had a clinical diagnosis of Inflammatory Breast Cancer (IBC). Twenty-two patients had CTCs detected (55%), the average number of CTCs was 8.6 (0-135) with a median follow up of two months. Of the patients who had CTCs detected and had HER2+ disease (IHC/FISH), 83% (5/6) had concordance in HER2+ CTCs. Interestingly, in the subset of patients who had HER2 negative disease (ICH/FISH) and had detectable CTCs, there was discordance in HER2 status: 44% (7/16) had HER2+ CTCs and all but one had Luminal A disease. Two patients have been started on HER2 targeted therapy based on finding HER2+ CTCs. One of these patients had 22 CTCs, 8 of which were HER2+, was initiated on HER-2 combined regimen and at a repeat evaluation in 3 months demonstrated 0 CTCs and clinical response.

Conclusions

CTCs offer a new and innovative approach to detect HER2+ cells in MBC. Tissue analysis with IHC and FISH has been the gold standard but these methods are unable to account for disease phenotyopic hetereogeity and identify patients who have CSCs (HER2+) and therefore would benefit from HER2 targeted therapy. This warrants further investigation in a prospective trial in Luminal disease to formally compare these methods and correlate the results with clinical outcomes.

Citation Format: Laura Austin, Zhaomei Mu, Tiffany Avery, Rebecca Jaslow, Carmela Paolillo, Angela Toss, Paolo Fortuna, Ye Zhong, Hushan Yang, Massimo Cristofanilli. Circulating tumor cells (CTCs) detect HER2+ status and phenotypic heterogeneity in metastatic breast cancer (MBC) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P4-01-11.

Abstract P2-04-03: Circulating tumor DNA (ctDNA) provides molecular monitoring for inflammatory breast cancer (IBC)

Background

Inflammatory Breast Cancer (IBC) is a clinicopathologic diagnosis characterized by rapid progression, resistance to treatment and poor prognosis. It is often an incurable disease with complex molecular features including somatic mutations that evolve in relation to genomic instability and selective treatment pressure. Monitoring disease by performing multiple biopsies may not be feasible and puts the patient at risk with each invasive procedure. Circulating DNA fragments carrying tumor-specific sequence alterations (ctDNA) are found in blood and offer the possibility of longitudinal non-invasive molecular monitoring of the disease by detecting actionable mutations.

Methods

This is an observational analysis of 35 IBC patients who failed standard therapies and had plasma analyzed for ctDNA detection. Selection criteria included progression of disease after standard therapies, need to detect novel molecular abnormalities for possible therapeutic targeting, or confirmation of genomic abnormalities already demonstrated in tissue analysis. Guardant Health performed the plasma analysis (Guardant360™); first ctDNA was isolated from plasma, then a panel of 54 gene mutations associated with solid tumors as reported in the COSMIC database were sequenced to concurrently analyze somatic mutations and gene amplification using single-molecule digital sequencing technology.

Results

All patients had IBC and 80% had metastatic disease; 37% of patients were ER+/HER2-, 14% ER+/HER2+, 23% ER-/HER2+, and 26% ER-/HER2-. 94% of patients with stage III or IV tumors had ctDNA alterations detected. The most common mutations were TP53 (49%), PIK3CA (20%), ERBB2 (17%), NOTCH1 (17%), and ALK (11%). Twelve patients also had next generation sequencing (NGS) analysis of tissue biopsy and 75% of these patients demonstrated at least one concordant mutation. The genomic information obtained from ctDNA, NGS or both was used to select treatments in 11 cases (31%). HER2 targeted therapy was continued in four patients with HER2+ disease after ctDNA confirmed ERBB2 alteration or amplification. A patient with ER+/HER2+ disease who progressed on HER2 targeted therapies, demonstrated ERBB2 and PIK3CA mutations on ctDNA; she was changed to exemestane/everolimus with objective response for several months. Repeat ctDNA at time of progression showed ERBB2 mutation only; she was changed to Trastuzumab/everolimus/vinorelbine. Moreover, a combination of lapatinib and capecitabine was initiated on a patient with a triple negative, chemo-refractory tumor that on ctDNA revealed EGFR and ERBB2 mutations; a repeated ctDNA after 5 months of therapy EGFR and ERBB2 mutations were not detected and she remains without evidence of progression.

Conclusions

Evaluation and longitudinal monitoring of IBC patients using ctDNA allows for identification of genomic abnormalities in all patients with advanced disease and to perform real-time molecular monitoring. The discovery of actionable genomic abnormalities is driving the management of this aggressive and treatment refractory form of breast cancer with potential future impact on outcome.

Citation Format: Laura Austin, Paolo Fortina, Dragan Sebisanovic, LaiMun Siew, Aubrey Zapanta, Benjamin J Schiller, Gangwu Mei, Helmy Eltoukhy, AmirAli Talasaz, Massimo Cristofanilli. Circulating tumor DNA (ctDNA) provides molecular monitoring for inflammatory breast cancer (IBC) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-04-03.

Improved upper limits on the stochastic gravitational-wave background from 2009-2010 LIGO and Virgo data

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Ω_{GW}(f)=Ω_{α}(f/f_{ref})^{α}, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of α=0, we constrain the energy density of the stochastic background to be Ω_{GW}(f)<5.6×10^{-6}. For the 600-1000 Hz band, Ω_{GW}(f)<0.14(f/900  Hz)^{3}, a factor of 2.5 lower than the best previously reported upper limits. We find Ω_{GW}(f)<1.8×10^{-4} using a spectral index of zero for 170-600 Hz and Ω_{GW}(f)<1.0(f/1300  Hz)^{3} for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.

Cancer stem cells: implications for cancer therapy

The survival of patients with cancer has improved significantly, primarily because of multidisciplinary care, improved chemotherapeutic agents in both the adjuvant and metastatic settings, the introduction of targeted biologic agents, and the incorporation of palliative care services into the management scheme. However, despite these advances, a significant proportion of patients continue to experience recurrence after adjuvant treatment, and survival associated with stage IV solid tumors still remains low. A primary or acquired resistance to chemotherapeutic and biologic agents is responsible for the failure of many of the agents used to treat patients with a malignancy. This can be explained by the presence of intratumoral heterogeneity and the molecular complexity of many cancers. Factors contributing to intratumoral heterogeneity include genetic mutations, interactions with the microenvironment-and the presence of cancer stem cells. Cancer stem cells have been identified in a number of solid tumors, including breast cancer, brain tumors, lung cancer, colon cancer, and melanoma. Cancer stem cells have the capacity to self-renew, to give rise to progeny that are different from them, and to utilize common signaling pathways. Cancer stem cells may be the source of all the tumor cells present in a malignant tumor, the reason for the resistance to the chemotherapeutic agent used to treat the malignant tumor, and the source of cells that give rise to distant metastases. This review will focus on properties of cancer stem cells; will compare and contrast the cancer stem cell model with the clonal evolution model of tumorigenesis; will discuss the role of cancer stem cells in the development of resistance to chemotherapy; and will review the therapeutic implications and challenges of targeting cancer stem cells, with an assessment of the potential such an approach holds for improving outcomes for patients with cancer.

TP53 mutations detected in circulating tumor cells present in the blood of metastatic triple negative breast cancer patients

Introduction

Circulating tumor cells (CTCs) are tumor cells shed from either primary tumors or its metastases that circulate in the peripheral blood of patients with metastatic cancers. The molecular characterization of the CTCs is critical to identifying the key drivers of cancer metastasis and devising therapeutic approaches. However, the molecular characterization of CTCs is difficult to achieve because their isolation is a major technological challenge.

Methods

CTCs from two triple negative breast cancer patients were enriched using CellSearch and single cells selected by DEPArray™. A TP53 R110 fs*13 mutation identified by next generation sequencing in the breast and chest skin biopsies of both patients was studied in single CTCs.

Results

From 6 single CTC isolated from one patient, 1 CTC had TP53 R110 delC, 1 CTC showed the TP53 R110 delG mutation, and the remaining 4 single CTCs showed the wild type p53 sequence; a pool of 14 CTCs isolated from the same patient also showed TP53 R110 delC mutation. In the tumor breast tissue of this patient, only the TP53 R110 delG mutation was detected. In the second patient a TP53 R110 delC mutation was detected in the chest wall skin biopsy; from the peripheral blood of this patient, 5 single CTC and 6 clusters of 2 to 6 CTCs were isolated; 3 of the 5 single CTCs showed the TP53 R110 delC mutation and 2 CTCs showed the wild type TP53 allele; from the clusters, 5 showed the TP53 R110 delC mutation, and 1 cluster the wild type TP53 allele. Single white blood cells isolated as controls from both patients only showed the wild type TP53 allele.

Conclusions

We are able to isolate uncontaminated CTCs and achieve single cell molecular analysis. Our studies showed the presence of different CTC sub-clones in patients with metastatic breast cancer. Some CTCs had the same TP53 mutation as their matching tumor samples although others showed either a different TP53 mutation or the wild type allele. Our results indicate that CTCs could represent a non-invasive source of cancer cells from which to determine genetic markers of the disease progression and potential therapeutic targets.

Electronic supplementary material

The online version of this article (doi:10.1186/s13058-014-0445-3) contains supplementary material, which is available to authorized users.

Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension Gμ below 10(-8) in some regions of the cosmic string parameter space.

An autoradiographic study of the flow of protein and RNA along peripheral nerve

Both chicken spinal cord and the posterior chamber of the rat eye have been injected with either [3H]leucine or [3H]orotic acid. The movement of newly synthesized protein and RNA down the sciatic and optic nerves was followed by means of autoradiography. Protein moved down both nerves by axoplasmic flow, the protein being confined to intra-axonal spaces. RNA appeared to move at about the same rate as protein, but much of the newly formed RNA appeared in structures outside the axons, particularly in Schwann and glial cells. There was, however a considerable proportion of the RNA inside the axons. This RNA may be involved in the direction of protein synthesis at sites along the axonal processes.

Auditory neuropathy: a potentially under-recognized neonatal intensive care unit sequela

Auditory neuropathy (AN) is a hearing disorder that affects newborns. Those with high-risk neonatal histories, family history of childhood hearing loss, and hyperbilirubinemia are at greatest risk. Current neonatal intensive care unit (NICU) hearing screening methods that rely only on otoacoustic emissions will fail to detect this disorder. Auditory neuropathy differs from conductive hearing loss and sensorineural hearing loss; a specific constellation of findings on audiologic evaluation are diagnostic of this disorder. The pathophysiology of AN is unclear; however, it may be caused by demyelinization or degeneration at points along the auditory pathway. The actual incidence of AN is unknown; it is more prevalent in high-risk infants. The course of AN varies widely among patients. Current management ranges from close monitoring of the child's development to cochlear implantation. Neonatal intensive care unit nurses need to be aware of this disorder to help support and educate at-risk families and to alert them of the need to monitor hearing and language development in their infants.

Short-term beta-amyloid vaccinations do not improve cognitive performance in cognitively impaired APP + PS1 mice

Prior work demonstrated that beta-amyloid (A beta) immunotherapy for 8 months prevented cognitive impairment in 16-month-old APP + PS1 transgenic mice. In the present study, 4 immunizations administered biweekly to cognitively impaired 16-month-old transgenic mice could not reverse deficits in working memory or reference memory in the radial arm water maze or in visual platform recognition, possibly because of inadequate antibody exposure. Nontransgenic mice showed cognitive savings between the 16- and 18-month test periods, but the transgenic groups did not. These results suggest that a longer period of active immunotherapy, or passive immunization, may be required to provide sufficient antibody titers to improve cognition in older transgenic mice. A beta-based immunotherapy for Alzheimer's disease will likely be more successful prophylactically than therapeutically.

A survey of tissue viability nurses' role and background in one region

The shift in NHS service provision towards primary care has made investigation of clinical nurse specialists' role in this setting an important issue. This article reports the findings of a preliminary survey of tissue viability nurses in one region

Presymptomatic motor neuron loss and reactive astrocytosis in the SOD1 mouse model of amyotrophic lateral sclerosis

In familial amyotrophic lateral sclerosis (fALS), there is a need to establish more precisely the progression of the disease, particularly whether there is gradual presymptomatic neuronal loss or an abrupt loss coinciding with the symptomatic stage. To elucidate this, we investigated the progression of motor neuron loss through morphological techniques, reactive astrocytosis, and expression of ubiquitin and neurofilament proteins, by immunohistochemistry, in SOD1 G93A mice with a protracted disease course and control mice. Loss of motor neurons in SOD1 G93A mice followed a biphasic progression, with an initial loss at 126 days of age, followed by a gradual loss from onset of symptoms through to end-stage disease. Reactive astrocytosis was first observed at 70 days of age and showed a gradual increase through to end-stage disease. This suggests that there is a need for early detection of fALS cases, and potential therapeutic treatments may be more beneficial if administered at an early stage.

The role of physicians in mammography referral for older Caribbean women in Canada

BACKGROUND

Despite the fact that the proportion of immigrant and minority women who consult a general practitioner about their health is similar to that of their Canadian-born counterparts, studies suggest that they are less likely to be screened for breast cancer. This study examines physician characteristics associated with mammography referral and perceived barriers to mammography among family physicians serving the Caribbean community of Toronto.

METHODS

The study consisted of a mail-back family physician survey.

RESULTS

Among the 64 physicians who responded to the survey, over half reported that they were "very likely" to refer women for mammography during a regular preventive check-up. Among physician variables, only the amount of time spent on patient education was significantly associated with the likelihood of referral. Regarding perceived barriers, for male physicians, patient refusal and intervention causing patient discomfort were significantly associated with referral. For female physicians, only forgetting to provide service was identified as a significant barrier to referral.

INTERPRETATION

An increased emphasis on patient education may help to increase screening referral among all physicians. Gender differences in perceived barriers to referral suggest that the gender of the physician is of major importance to the Caribbean community.

Leukemia inhibitory factor enhances regeneration in skeletal muscles after myoblast transplantation

Cell-based therapies, such as myoblast transfer therapy, are likely to become an integral part of any approach to treat myopathies such as Duchenne muscular dystrophy. Previous studies have shown that an increased level of regeneration in the host muscle enhances incorporation of donor myoblasts. Leukemia inhibitory factor (LIF) increases the number of dystrophic fibers expressing dystrophin after myoblast transplantation and enhances regeneration in injured and diseased muscle. Morphometric analysis was used to investigate whether an increased level of regeneration is induced by LIF after myoblast transplantation. We found that, in muscles treated with LIF, the number of fibers undergoing regeneration was increased. The increased incorporation of donor myoblasts and thus dystrophin expression induced by LIF may be due, at least in part, to an increased level of regeneration of dystrophic muscle.

In vivo and in vitro correction of the mdx dystrophin gene nonsense mutation by short-fragment homologous replacement

Targeted genetic correction of mutations in cells is a potential strategy for treating human conditions that involve nonsense, missense, and transcriptional splice junction mutations. One method of targeted gene repair, single-stranded short-fragment homologous replacement (ssSFHR), has been successful in repairing the common deltaF508 3-bp microdeletion at the cystic fibrosis transmembrane conductance regulator (CFTR) locus in 1% of airway epithelial cells in culture. This study investigates in vitro and in vivo application of a double-stranded method variant of SFHR gene repair to the mdx mouse model of Duchenne muscular dystrophy (DMD). A 603-bp wild-type PCR product was used to repair the exon 23 C-to-T mdx nonsense transition at the Xp21.1 dys locus in cultured myoblasts and in tibialis anterior (TA) from male mdx mice. Multiple transfection and variation of lipofection reagent both improved in vitro SFHR efficiency, with successful conversion of mdx to wild-type nucleotide at the dys locus achieved in 15 to 20% of cultured loci and in 0.0005 to 0.1% of TA. The genetic correction of mdx myoblasts was shown to persist for up to 28 days in culture and for at least 3 weeks in TA. While a high frequency of in vitro gene repair was observed, the lipofection used here appeared to have adverse effects on subsequent cell viability and corrected cells did not express dystrophin transcript. With further improvements to in vitro and in vivo gene repair efficiencies, SFHR may find some application in DMD and other genetic neuromuscular disorders in humans.

Leukemia inhibitory factor ameliorates muscle fiber degeneration in the mdx mouse

Although the muscles of the mdx mouse lack dystrophin, the protein absent in muscles of humans affected with Duchenne muscular dystrophy (DMD), the only mdx muscle to degenerate in a manner similar to those of DMD boys is the diaphragm. We have previously shown that leukemia inhibitory factor (LIF) is a trauma factor that enhances muscle repair in vivo and, when applied exogenously, increases the fiber size of mdx skeletal muscle. Furthermore, we developed a controlled release device for LIF based on a calcium alginate rod (release rate about 0.5% per day). These rods were sutured to the abdominal surface of the hemidiaphragm of mdx mice 3 months old. At age 6 months the mice were killed and the diaphragm muscles fixed and sectioned. The sections showed obvious muscle degeneration at 3 months of age in mdx mouse diaphragms and further degeneration at 6 months in saline-perfused muscle. Hemidiaphragm muscles continuously exposed to LIF over the same period contained more normal myofibers, larger regenerated fibers, and less adipose tissue and other non-contractile tissue. Morphometric analysis of the diaphragm sections was carried out. The LIF-treated animals showed a significant increase in fiber number and size compared to saline rod controls. The amount of nonmuscle (connective tissue and adipose tissue) was significantly reduced and the maximum force-producing capacity of isolated diaphragm muscle strips was higher in LIF-treated mice. The results demonstrate that LIF treatment ameliorates the dystrophic abnormalities in mdx mouse diaphragm.

Palliative care: community nurses' perceptions of quality

OBJECTIVES

To identify community nurses' perceptions of quality care provision for patients requiring palliative care.

DESIGN

Semi-structured interviews were conducted with community nurses working within the district nursing service. An adaptation of Flanagan's critical incident technique was employed to elicit factors associated with high or poor quality palliative care. Interviews were tape recorded and transcribed. Data were analysed using thematic content analysis, recurrent themes being agreed by the research team.

SETTING

One community healthcare trust.

SUBJECTS

62 members of the district nursing team (grades B-H).

RESULTS

Respondents recounted the context in which high quality palliative care could be provided, the actions required, and the indicators that suggested the desired level of care had been achieved. Key factors identified were: the early referral of patients to the district nursing service, family circumstances, the availability of time, the accessibility of services and equipment, and the relationship with other healthcare professionals and informal carers. There was a general view that a positive outcome had been achieved when patients retained control over their circumstances and died a peaceful death, in the place of their choice, supported by their family.

CONCLUSIONS

Community nurses were able to articulate clearly the essential components of high quality care. Whilst these factors do not represent a comprehensive list, they are put forward as a useful starting point for standard setting and subsequent audit.

Community nurses' perceptions of patient 'compliance' in wound care: a discourse analysis

As part of an interview study of community nurses' perceptions of their work, 62 staff working within the district nursing service in one English National Health Service Trust (grades B-H) were asked to recount occasions when they had been involved in wound care and to discuss the ways in which working with patients who required such care could be either enhanced or made difficult. A large number of respondents expressed the view that non-compliance could pose serious problems for the management of wounds. Data relating to compliance are presented here and are interpreted in the light of discourse analysis, an approach which permits the researcher to focus on the meanings underlying the communications of research participants and to interpret those meanings in the light of social and cultural mores and influences. The authors found that non-compliance could be explained by nurses in a number of different ways. These ranged from passive resistance, which could be due to ignorance or lack of motivation, through overt refusal, to deliberate interference in order to prolong treatment. It also seeks to outline some of the factors that appear to motivate the nurses' desire to achieve compliance.

Increased levels of leukemia inhibitory factor mRNA in muscular dystrophy and human muscle trauma

Leukemia inhibitory factor (LIF) is an important muscle trauma factor both after crush injury and in the mdx mouse dystrophy model. It is important to establish which growth factors have a role in human muscle regeneration due to potential clinical therapeutic applications. As there is limited information concerning LIF expression in human muscle, we investigated the relative levels of LIF messenger ribonucleic acid (mRNA) in human muscle injury. Semiquantitative reverse transcriptase followed by polymerase chain reaction was used to amplify LIF message. We found that although LIF mRNA is expressed in low levels in control muscle, a sevenfold increase occurred after orthopedic muscle trauma and a marked 19-fold increase in dystrophic muscle (P < 0.002). These results indicate that LIF mRNA is upregulated in surgical and especially medical muscle injury with repeated myonecrosis. Muscle growth factors such as LIF may assist in future muscle rehabilitation after injury.

An evaluation of information cards as a means of improving communication between hospital and primary care for women with breast cancer

This paper describes an intervention study aimed at improving communication between hospital services and the primary health care team. A series of information cards were developed by breast specialist secondary care professionals for members of the primary health care team. Women with breast cancer were involved in the communication pathway and were asked to take the information cards to their own general practitioner (GP) practice. It was envisaged that women would be more likely to utilize the primary health care team for information if they were aware that the primary health care team was in receipt of information specific to the treatment they had received. Women newly diagnosed with breast cancer were allocated to either an intervention (n=38) or non-intervention (n=38) group. Patient interviews were carried out around the time of diagnosis and at 4 months from diagnosis. Interviews were also carried out with 31 GPs to ascertain their views on the provision of information for women with breast cancer, and on the information cards if relevant. The study findings were interesting although not significant in terms of the direction anticipated. The cards did not impact on the utilization of the primary health care team and women in the intervention group were no more likely to utilize primary care sources of information than women in the non-intervention group. Factors such as the long-standing relationship women had with their GP, the perceived lack of specialist knowledge on the part of GPs and district nurses, and the women's perception that information seeking was not a tangible reason for primary care contact had an impact on information-seeking behaviour.