Synchronous or metachronous breast and colorectal cancers in younger-than-average-age patients: a case series.

BACKGROUND: The incidence of breast and colorectal cancer (CRC) in younger-than-average-age patients is rising and poorly understood. This is the largest study on patients with both cancers who are less than 60 years old and aims to characterize demographic, clinicopathologic, and genetic features and describe therapeutic dilemmas and management strategies. MATERIALS AND METHODS: This is a retrospective medical records review of patients at the University of California San Francisco with both primary breast and CRC before age 60. RESULTS: Fifty-one patients were identified; 41 had detailed medical records. Median age of diagnosis with breast cancer was 43 (range 27-59) and CRC was 50 (28-59). Most were Caucasian (38, 74.5%) and never smokers (23, 56.1%); about half were current alcohol consumers (20, 48.8%) and about one-third had sedentary jobs (14, 34.1%). Average BMI was 25.8 (range: 14-49), and 30% were overweight or obese. Breast was the first cancer diagnosed in 36 patients (70.6%) and 44 (86.3%) had a metachronous CRC diagnosis. Breast cancer was early stage (0-2) in 32 (78.0%) patients whereas CRC was split between early stage (1-2) in 14 (34.1%) and later stage (3-4) in 19 (46.2%). Ten patients (24.3%) had a known germline mutation, although 23 (56.1%) had a family history of cancer in a first-degree relative. CONCLUSION: Younger patients with both breast and CRC are a unique cohort, often without known risk factors. Alcohol consumption and sedentary jobs were the most common risk factors, and about one-quarter had a known genetic predisposition. Comanagement of both cancers requires individualized, multidisciplinary care.

Outcomes and clinicopathologic characteristics associated with disseminated tumor cells in bone marrow after neoadjuvant chemotherapy in high-risk early stage breast cancer: the I-SPY SURMOUNT study.

PURPOSE: Disseminated tumor cells (DTCs) expressing epithelial markers in the bone marrow are associated with recurrence and death, but little is known about risk factors predicting their occurrence. We detected EPCAM+/CD45- cells in bone marrow from early stage breast cancer patients after neoadjuvant chemotherapy (NAC) in the I-SPY 2 Trial and examined clinicopathologic factors and outcomes. METHODS: Patients who signed consent for SURMOUNT, a sub-study of the I-SPY 2 Trial (NCT01042379), had bone marrow collected after NAC at the time of surgery. EPCAM+CD45- cells in 4 mLs of bone marrow aspirate were enumerated using immunomagnetic enrichment/flow cytometry (IE/FC). Patients with > 4.16 EPCAM+CD45- cells per mL of bone marrow were classified as DTC-positive. Tumor response was assessed using the residual cancer burden (RCB), a standardized approach to quantitate the extent of residual invasive cancer present in the breast and the axillary lymph nodes after NAC. Association of DTC-positivity with clinicopathologic variables and survival was examined. RESULTS: A total of 73 patients were enrolled, 51 of whom had successful EPCAM+CD45- cell enumeration. Twenty-four of 51 (47.1%) were DTC-positive. The DTC-positivity rate was similar across receptor subtypes, but DTC-positive patients were significantly younger (p = 0.0239) and had larger pretreatment tumors compared to DTC-negative patients (p = 0.0319). Twenty of 51 (39.2%) achieved a pathologic complete response (pCR). While DTC-positivity was not associated with achieving pCR, it was significantly associated with higher RCB class (RCB-II/III, 62.5% vs. RCB-0/I; 33.3%; Chi-squared p = 0.0373). No significant correlation was observed between DTC-positivity and distant recurrence-free survival (p = 0.38, median follow-up = 3.2 years). CONCLUSION: DTC-positivity at surgery after NAC was higher in younger patients, those with larger tumors, and those with residual disease at surgery.

The cancer glycocalyx mechanically primes integrin-mediated growth and survival.

Malignancy is associated with altered expression of glycans and glycoproteins that contribute to the cellular glycocalyx. We constructed a glycoprotein expression signature, which revealed that metastatic tumours upregulate expression of bulky glycoproteins. A computational model predicted that these glycoproteins would influence transmembrane receptor spatial organization and function. We tested this prediction by investigating whether bulky glycoproteins in the glycocalyx promote a tumour phenotype in human cells by increasing integrin adhesion and signalling. Our data revealed that a bulky glycocalyx facilitates integrin clustering by funnelling active integrins into adhesions and altering integrin state by applying tension to matrix-bound integrins, independent of actomyosin contractility. Expression of large tumour-associated glycoproteins in non-transformed mammary cells promoted focal adhesion assembly and facilitated integrin-dependent growth factor signalling to support cell growth and survival. Clinical studies revealed that large glycoproteins are abundantly expressed on circulating tumour cells from patients with advanced disease. Thus, a bulky glycocalyx is a feature of tumour cells that could foster metastasis by mechanically enhancing cell-surface receptor function.

Adaptive Randomization of Neratinib in Early Breast Cancer.

BACKGROUND: The heterogeneity of breast cancer makes identifying effective therapies challenging. The I-SPY 2 trial, a multicenter, adaptive phase 2 trial of neoadjuvant therapy for high-risk clinical stage II or III breast cancer, evaluated multiple new agents added to standard chemotherapy to assess the effects on rates of pathological complete response (i.e., absence of residual cancer in the breast or lymph nodes at the time of surgery). METHODS: We used adaptive randomization to compare standard neoadjuvant chemotherapy plus the tyrosine kinase inhibitor neratinib with control. Eligible women were categorized according to eight biomarker subtypes on the basis of human epidermal growth factor receptor 2 (HER2) status, hormone-receptor status, and risk according to a 70-gene profile. Neratinib was evaluated against control with regard to 10 biomarker signatures (prospectively defined combinations of subtypes). The primary end point was pathological complete response. Volume changes on serial magnetic resonance imaging were used to assess the likelihood of such a response in each patient. Adaptive assignment to experimental groups within each disease subtype was based on Bayesian probabilities of the superiority of the treatment over control. Enrollment in the experimental group was stopped when the 85% Bayesian predictive probability of success in a confirmatory phase 3 trial of neoadjuvant therapy reached a prespecified threshold for any biomarker signature ("graduation"). Enrollment was stopped for futility if the probability fell to below 10% for every biomarker signature. RESULTS: Neratinib reached the prespecified efficacy threshold with regard to the HER2-positive, hormone-receptor-negative signature. Among patients with HER2-positive, hormone-receptor-negative cancer, the mean estimated rate of pathological complete response was 56% (95% Bayesian probability interval [PI], 37 to 73%) among 115 patients in the neratinib group, as compared with 33% among 78 controls (95% PI, 11 to 54%). The final predictive probability of success in phase 3 testing was 79%. CONCLUSIONS: Neratinib added to standard therapy was highly likely to result in higher rates of pathological complete response than standard chemotherapy with trastuzumab among patients with HER2-positive, hormone-receptor-negative breast cancer. (Funded by QuantumLeap Healthcare Collaborative and others; I-SPY 2 TRIAL ClinicalTrials.gov number, NCT01042379.).

Phase II study of irinotecan and temozolomide in breast cancer patients with progressing central nervous system disease.

PURPOSE: Breast cancer patients with progressing central nervous system (CNS) disease have limited treatment options. Few chemotherapy drugs with activity in breast cancer have well-documented CNS penetration. This phase 2 trial evaluated efficacy and safety of irinotecan 125 mg/m2 on days 1 and 15 with temozolomide 100 mg/m2 days 1-7 and days 15-21 of a 28 day cycle. METHODS: Breast cancer patients of any biological subtype and progressing brain metastases and/or leptomeningeal disease (LMD) were eligible. The primary endpoint was CNS response rate. Secondary endpoints were clinical benefit rate (CBR), time to progression (TTP), and overall survival (OS). Imaging studies evaluating intracranial and extracranial response were performed every 8 weeks. RESULTS: Thirty patients were evaluable for safety and efficacy. The most common hematologic and non-hematologic adverse events were neutropenia, and nausea and fatigue, respectively. There were two confirmed CNS partial responses (PR) and five patients with stable disease in the CNS ≥ 16 weeks, resulting in a 7% PR and 23% CBR. Median TTP was 2.3 months (range 13-444 days), and median OS from treatment initiation until death was 4.9 months (range 20-1023 days). Excluding patients with LMD, median TTP and OS were 3.1 and 5.6 months, respectively. Only one patient progressed systemically before CNS progression. CONCLUSIONS: The combination of irinotecan and temozolomide was well tolerated, demonstrated some clinical activity across multiple breast cancer subtypes with progressing CNS disease, and offers a reasonable option for patients who are not candidates for further radiation or clinical trials.

Enrichment and Detection of Circulating Tumor Cells and Other Rare Cell Populations by Microfluidic Filtration.

The current standard methods for isolating circulating tumor cells (CTCs) from blood involve EPCAM-based immunomagnetic approaches. A major disadvantage of these strategies is that CTCs with low EPCAM expression will be missed. Isolation by size using filter membranes circumvents the reliance on this cell surface marker, and can facilitate the capture not only of EPCAM-negative CTCs but other rare cells as well. These cells that are trapped on the filter membrane can be characterized by immunocytochemistry (ICC) , enumerated and profiled to elucidate their clinical significance. In this chapter, we discuss advances in filtration systems to capture rare cells as well as downstream ICC methods to detect and identify these cells. We highlight our recent clinical study demonstrating the feasibility of using a novel method consisting of automated microfluidic filtration and sequential ICC for detection and enumeration of CTCs, as well as circulating mesenchymal cells (CMCs), circulating endothelial cells (CECs), and putative circulating stem cells (CSCs). We hypothesize that simultaneous analysis of circulating rare cells in blood of cancer patients may lead to a better understanding of disease progression and development of resistance to therapy.

Circulating tumor cells in breast cancer: applications in personalized medicine.

Recent technological advancements in rare cell analysis have facilitated the detection of circulating tumor cells (CTCs) in the blood of patients diagnosed with breast and other types of cancers. Numerous clinical studies involving the enumeration of CTCs in breast cancer patients have unequivocally demonstrated the prognostic value of these cells. Evidence from recent molecular studies indicates that CTCs may be potential surrogate markers for systemic disease. As such, real-time assessment of therapeutic biomarkers in breast CTCs, such as the estrogen receptor (ER) and the human epidermal growth factor receptor 2 (HER2), may have a tremendous impact in guiding-targeted cancer therapy. In this review, we discuss the clinical implications of CTC detection and its potential utility for personalized medicine in breast cancer.

Serial expression analysis of breast tumors during neoadjuvant chemotherapy reveals changes in cell cycle and immune pathways associated with recurrence and response.

INTRODUCTION: The molecular biology involving neoadjuvant chemotherapy (NAC) response is poorly understood. To elucidate the impact of NAC on the breast cancer transcriptome and its association with clinical outcome, we analyzed gene expression data derived from serial tumor samples of patients with breast cancer who received NAC in the I-SPY 1 TRIAL. METHODS: Expression data were collected before treatment (T1), 24-96 hours after initiation of chemotherapy (T2) and at surgery (TS). Expression levels between T1 and T2 (T1 vs. T2; n = 36) and between T1 and TS (T1 vs. TS; n = 39) were compared. Subtype was assigned using the PAM50 gene signature. Differences in early gene expression changes (T2 - T1) between responders and nonresponders, as defined by residual cancer burden, were evaluated. Cox proportional hazards modeling was used to identify genes in residual tumors associated with recurrence-free survival (RFS). Pathway analysis was performed with Ingenuity software. RESULTS: When we compared expression profiles at T1 vs. T2 and at T1 vs. TS, we detected significantly altered expression of 150 and 59 transcripts, respectively. We observed notable downregulation of proliferation and immune-related genes at T2. Lower concordance in subtype assignment was observed between T1 and TS (62 %) than between T1 and T2 (75 %). Analysis of early gene expression changes (T2 - T1) revealed that decreased expression of cell cycle inhibitors was associated with poor response. Increased interferon signaling (TS - T1) and high expression of cell proliferation genes in residual tumors (TS) were associated with reduced RFS. CONCLUSIONS: Serial gene expression analysis revealed candidate immune and proliferation pathways associated with response and recurrence. Larger studies incorporating the approach described here are warranted to identify predictive and prognostic biomarkers in the NAC setting for specific targeted therapies. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00033397 . Registered 9 Apr 2002.

Advances in genomic characterization of circulating tumor cells.

Molecular characterization of circulating tumor cells (CTCs) found in the blood of cancer patients offers the potential to provide new insights into the biology of cancer metastasis. However, since they are rare and difficult to isolate, the molecular nature of CTCs remains poorly understood. In this paper, we reviewed a decade's worth of scientific literature (2003-2013) describing efforts on isolation and genomic analysis of CTCs. The limited number of CTC genomic studies we found attested to the infancy of this field of study. These initial reports, however, provide an important framework for future comprehensive exploration of CTC biology. For CTCs to be broadly accepted as therapeutic targets and biomarkers of metastatic spread, further in-depth molecular characterization is warranted.

Detection of cerebrospinal fluid tumor cells and its clinical relevance in leptomeningeal metastasis of breast cancer.

Circulating tumor cells are commonly observed in the peripheral blood of advanced breast cancer patients. We tested the feasibility of tumor cell detection in the cerebrospinal fluid (CSF) and studied its clinical relevance in leptomeningeal metastasis (LM) of breast cancer. CSF samples were collected from 38 metastatic breast cancer patients known or suspected to have LM. Control CSF samples were collected from 14 individuals without solid tumor malignancy. We used a modified CellSearch™ assay and an alternative EPCAM-based method involving immunomagnetic enrichment followed by flow cytometry (IE/FC) to enumerate CSF tumor cells (CSFTCs). CSFTCs were assayed at time of LM diagnosis and over the course of LM-directed therapy. We analyzed a total of 102 CSF samples with modified CellSearch™. The CSFTC counts were strongly correlated with the corresponding IE/FC results (Pearson's r = 0.94). Twenty-eight out of 30 samples in which malignant cells were identified by CSF cytology were CSFTC-positive by modified CellSearch™. Baseline CSFTC levels from 21 patients eventually diagnosed with LM were significantly higher than the controls (p = 0.0202), whereas 13 patients deemed not to have LM showed CSFTC results indistinguishable from the controls. In patients with serial samples, it was possible to monitor CSFTC levels as a potential biomarker of treatment response. CSFTC detection using a modified CellSearch™ assay demonstrated high sensitivity in detecting malignant cells in CSF and may be a promising method for diagnosing LM and monitoring LM during treatment.

Expression profiling of circulating tumor cells in metastatic breast cancer.

Circulating tumor cells (CTCs) are prognostic in all stages of breast cancer. However, since they are extremely rare, little is known about the molecular nature of these cells. We report a novel strategy for the isolation and expression profiling of pure populations of CTCs derived from peripheral blood. We developed a method to isolate CTCs based on immunomagnetic capture followed by fluorescence-activated cell sorting (IE/FACS). After assay validation using the BT474 cell line spiked into blood samples in vitro, RNA from CTCs isolated from the blood of five metastatic breast cancer (MBC) patients was linearly amplified and subjected to gene expression profiling via cDNA microarrays. We isolated a range of 9-993 captured CTCs from five MBC patients' blood and profiled their RNA in comparison to a diverse panel of primary breast tumors (n = 55). Unsupervised hierarchical clustering revealed that CTC profiles clustered with more aggressive subtypes of primary breast tumors and were readily distinguishable from peripheral blood (PB) and normal epithelium. Differential expression analysis revealed CTCs to have downregulated apoptosis, and they were distinguishable from PB by the relative absence of immune-related signals. As expected, CTCs from MBC had significantly higher risk of recurrence scores than primary tumors (p = 0.0073). This study demonstrates that it is feasible to isolate CTCs from PB with high purity through IE/FACS and profile them via gene expression analysis. Our approach may inform the discovery of therapeutic predictors and be useful for real-time identification of emerging resistance mechanisms in MBC patients.

Circulating tumor cells in hepatocellular carcinoma: a pilot study of detection, enumeration, and next-generation sequencing in cases and controls.

BACKGROUND: Circulating biomarkers are urgently needed in hepatocellular carcinoma (HCC). The aims of this study were to determine the feasibility of detecting and isolating circulating tumor cells (CTCs) in HCC patients using enrichment for epithelial cell adhesion molecule (EpCAM) expression, to examine their prognostic value, and to explore CTC-based DNA sequencing in metastatic HCC patients compared to a control cohort with non-malignant liver diseases (NMLD). METHODS: Whole blood was obtained from patients with metastatic HCC or NMLD. CTCs were enumerated by CellSearch then purified by immunomagnetic EpCAM enrichment and fluorescence-activated cell sorting. Targeted ion semiconductor sequencing was performed on whole genome-amplified DNA from CTCs, tumor specimens, and peripheral blood mononuclear cells (PBMC) when available. RESULTS: Twenty HCC and 10 NMLD patients enrolled. CTCs ≥ 2/7.5 mL were detected in 7/20 (35%, 95% confidence interval: 12%, 60%) HCC and 0/9 eligible NMLD (p = 0.04). CTCs ≥ 1/7.5 mL was associated with alpha-fetoprotein ≥ 400 ng/mL (p = 0.008) and vascular invasion (p = 0.009). Sequencing of CTC DNA identified characteristic HCC mutations. The proportion with ≥ 100x coverage depth was lower in CTCs (43%) than tumor or PBMC (87%) (p < 0.025). Low frequency variants were higher in CTCs (p < 0.001). CONCLUSIONS: CTCs are detectable by EpCAM enrichment in metastatic HCC, without confounding false positive background from NMLD. CTC detection was associated with poor prognostic factors. Sequencing of CTC DNA identified known HCC mutations but more low-frequency variants and lower coverage depth than FFPE or PBMC.

Subtype and pathway specific responses to anticancer compounds in breast cancer.

Breast cancers are comprised of molecularly distinct subtypes that may respond differently to pathway-targeted therapies now under development. Collections of breast cancer cell lines mirror many of the molecular subtypes and pathways found in tumors, suggesting that treatment of cell lines with candidate therapeutic compounds can guide identification of associations between molecular subtypes, pathways, and drug response. In a test of 77 therapeutic compounds, nearly all drugs showed differential responses across these cell lines, and approximately one third showed subtype-, pathway-, and/or genomic aberration-specific responses. These observations suggest mechanisms of response and resistance and may inform efforts to develop molecular assays that predict clinical response.

Isolation of circulating tumor cells by immunomagnetic enrichment and fluorescence-activated cell sorting (IE/FACS) for molecular profiling.

Circulating tumor cells (CTCs) are cells shed by the primary tumor into the blood stream capable of initiating distant metastasis. In the past decade, numerous assays have been developed to reliably detect these extremely rare cells. However, methods for purification of CTCs with little or no contamination of normal blood cells for molecular profiling are limited. We have developed a novel protocol to isolate CTCs by combining immunomagnetic enrichment and fluorescence-activated cell sorting (IE/FACS). The two-part assay includes (1) immunomagnetic capture using magnetic beads conjugated to monoclonal antibody against an epithelial cell adhesion marker (EpCAM) to enrich for tumor cells; and (2) FACS analysis using EpCAM to purify tumor cells away from mononuclear cells of hematopoietic lineage. Downstream molecular analyses of single and pooled cells confirmed the isolation of highly pure CTCs with characteristics typical that of malignant cells.

Circulating tumor cells in early lobular versus ductal breast cancer and their associations with prognosis.

This is a secondary data analysis of the TIPPING study, which included 1,121 patients with stage I-III breast cancer who had enumeration of CTCs (by either CellSearch or immunomagnetic enrichment and flow cytometry [IE/FC]) and disseminated tumor cells (DTCs) at the time of surgical resection between 1999 and 2012. The primary endpoint was mean number of CTCs by histology, taking into account method of detection and treatment type, and evaluation of histology specific prognostic cutpoints. Overall, patients with ILC had significantly higher CTC counts than those with IDC, a finding which persisted in the 382 patients with CTC enumeration by IE/FC method. Additionally, among those with primary surgery, patients with ILC had significantly higher mean CTC counts than those with IDC (mean 2.11 CTCs/mL versus 0.71 CTCs/mL respectively, p < 0.001), which persisted on multivariate analysis. Patients with ILC and CTC-high/DTC-high status trended towards reduced DRFS HR = 9.27, 95% CI 0.95-90.5, p = 0.055) and had significantly decreased BCSS (HR = 10.4, 95% CI 1.07-99.7, P = 0.043) compared with those who were CTC-low/DTC-low. In the IDC group, CTC-high/DTC-high status was not associated with either DRFS or BCSS. In neoadjvuantly treated patients, there was no significant difference in CTC counts in the ILC group versus the IDC group (mean 0.89 CTCs/mL versus 1.06 CTCs/mL respectively, p = 0.82). Our findings contribute to the limited literature on CTCs and DTCs in ILC, and suggest that clinical utility and optimal thresholds for CTC and DTC assays may differ by histologic subtype in early-stage breast cancer.

A phase II study of lapatinib and bevacizumab as treatment for HER2-overexpressing metastatic breast cancer.

Preclinical data have demonstrated that the combination of antihuman epidermal growth factor receptor-2 (anti-HER2) and antivascular endothelial growth factor (anti-VEGF)--targeted agents has antitumor activity; these data indicate certain patients with HER2-overexpressing breast cancer may derive clinical benefit from this combination. The purpose of this single-arm phase II study was to determine the efficacy and safety of the dual-targeting combination of lapatinib and bevacizumab. Women with HER2-overexpressing advanced breast cancer received 1,500 mg oral lapatinib daily plus 10 mg/kg IV bevacizumab every 2 weeks. The primary endpoint was progression-free survival (PFS) at week 12; secondary endpoints included overall tumor response rate (ORR), clinical benefit rate (CBR), duration of response, time-to-response, PFS, and safety. Circulating tumor cells (CTC) and circulating endothelial cells (CEC) were measured at baseline and during study treatment as potential response markers. Fifty-two patients with stage IV disease were enrolled. The 12-week investigator-assessed PFS rate was 69.2% (95% confidence interval [CI]: 54.9, 81.3). Median PFS was 24.7 weeks (95% CI: 20.4, 35.1), and the CBR was 30.8% (95% CI: 18.7, 45.1). Of 45 patients with measurable disease, 6 were determined to have a partial response per Response Evaluation Criteria in Solid Tumors (ORR: 13.3%; 95% CI: 5.1, 26.8). The most common adverse events (AEs) included diarrhea, rash, and fatigue; most of these were either grade 1 or 2. Clinical responses were correlated with decreases in CTC and CEC. Lapatinib plus bevacizumab was active in patients with HER2-overexpressing breast cancer. The AE profile of the combination was consistent with the known profiles for these agents.

Xenografts faithfully recapitulate breast cancer-specific gene expression patterns of parent primary breast tumors.

Though xenografts are used extensively for drug development in breast cancer, how well xenografts reflect the breadth of primary breast tumor subtypes has not been well characterized. Moreover, few studies have compared the gene expression of xenograft tumors to the primary tumors from which they were derived. Here we investigate whether the ability of human breast tumors (n = 20) to create xenografts in immune-deficient mice is associated with breast cancer immunohistochemical (IHC) and intrinsic subtype. We also characterize how precisely the gene expression of xenografts reprises that of parent breast tumors, using hierarchical clustering and other correlation-based techniques applied to Agilent 44K gene expression data from 16 samples including four matched primary tumor-xenograft pairs. Of the breast tumors studied, 25 % (5/20) generated xenografts. Receptor and intrinsic subtype were significant predictors of xenograft success, with all (4/4) triple-negative (TN) tumors and no (0/12) HR+Her2- tumors forming xenografts (P = 0.0005). Tumor cell expression of ALDH1, a stem cell marker, trended toward successful engraftment (P = 0.14), though CDK5/6, a basal marker, did not. Though hierarchical clustering across the 500 most variable genes segregated human breast tumors from xenograft tumors, when clustering was performed over the PAM50 gene set the primary tumor-xenograft pairs clustered together, with all IHC subtypes clustered in distinct groups. Greater similarity between primary tumor-xenograft pairs relative to random pairings was confirmed by calculation of the within-pair between-pair scatter ratio (WPBPSR) distribution (P = 0.0269), though there was a shift in the xenografts toward more aggressive features including higher proliferation scores relative to the primary. Triple-negative breast tumors demonstrate superior ability to create xenografts compared to HR+ tumors, which may reflect higher proliferation or relatively stroma-independent growth of this subtype. Xenograft tumors' gene expression faithfully resembles that of their parent tumors, yet also demonstrates a shift toward more aggressive molecular features.

Isolation and genomic analysis of circulating tumor cells from castration resistant metastatic prostate cancer.

BACKGROUND: The number of circulating tumor cells (CTCs) in metastatic prostate cancer patients provides prognostic and predictive information. However, it is the molecular characterization of CTCs that offers insight into the biology of these tumor cells in the context of personalized treatment. METHODS: We developed a novel approach to isolate CTCs away from hematopoietic cells with high purity, enabling genomic analysis of these cells. The isolation protocol involves immunomagnetic enrichment followed by fluorescence activated cell sorting (IE/FACS). To evaluate the feasibility of isolation of CTCs by IE/FACS and downstream genomic profiling, we conducted a pilot study in patients with metastatic castration resistant prostate cancer (CRPC). Twenty (20) sequential CRPC patients were assayed using CellSearch™. Twelve (12) patients positive for CTCs were subjected to immunomagnetic enrichment and fluorescence activated cell sorting (IE/FACS) to isolate CTCs. Genomic DNA of CTCs was subjected to whole genome amplification (WGA) followed by gene copy number analysis via array comparative genomic hybridization (aCGH). RESULTS: CTCs from nine (9) patients successfully profiled were observed to have multiple copy number aberrations including those previously reported in primary prostate tumors such as gains in 8q and losses in 8p. High-level copy number gains at the androgen receptor (AR) locus were observed in 7 (78%) cases. Comparison of genomic profiles between CTCs and archival primary tumors from the same patients revealed common lineage. However, high-level copy number gains in the AR locus were observed in CTCs, but not in the matched archival primary tumors. CONCLUSIONS: We developed a new approach to isolate prostate CTCs without significant leukocyte admixture, and to subject them to genome-wide copy number analysis. Our assay may be utilized to explore genomic events involved in cancer progression, e.g. development of castration resistance and to monitor therapeutic efficacy of targeted therapies in clinical trials in a relatively non-invasive manner.

Biologic markers determine both the risk and the timing of recurrence in breast cancer.

Breast cancer has a long natural history. Established and emerging biologic markers address overall risk but not necessarily timing of recurrence. 346 adjuvant naïve breast cancer cases from Guy's Hospital with 23 years minimum follow-up and archival blocks were recut and reassessed for hormone-receptors (HR), HER2-receptor and grade. Disease-specific survival (DSS) was analyzed by recursive partitioning. To validate insights from this analysis, gene-signatures (proliferative and HR-negative) were evaluated for their ability to predict early versus late metastatic risk in 683 node-negative, adjuvant naïve breast cancers annotated with expression microarray data. Risk partitioning showed that adjuvant naïve node-negative outcome risk was primarily partitioned by tumor receptor status and grade but not tumor size. HR-positive and HER2-negative (HRpos) risk was partitioned by tumor grade; low grade cases have very low early risk but a 20% fall-off in DSS 10 or more years after diagnosis. Higher grade HRpos cases have risk over >20 years. Triple-negative (Tneg) and HER2-positive (HER2pos) cases DSS events occurred primarily within the first 5 years. Among node-positive cases, only low grade conferred late risk, suggesting that proliferative gene signatures that identify proliferation would be important for predicting early but not late recurrence. Using pooled data from four publicly available data sets for node-negative tumors annotated with gene expression and outcome data, we evaluated four prognostic gene signatures: two proliferation-based and two immune function-based. Tumor proliferative capacity predicted early but not late metastatic risk for HRpos cases. The immune function or HRneg specific signatures predicted only early metastatic risk in Tneg and HER2pos cases. Breast cancer prognostic signatures need to inform both risk and timing of metastatic events and may best be applied within subsets. Current signatures predict for outcome risk within 5 years of diagnosis. Predictors of late risk for HR positive disease are needed.

Evaluation of disseminated tumor cells and circulating tumor cells in patients with breast cancer receiving adjuvant zoledronic acid.

We evaluated disseminated tumor cells (DTCs) and circulating tumor cells (CTCs) in patients with stage I-III breast cancer with >4 MM/mL DTC at baseline who received adjuvant zoledronic acid (ZOL). ZOL was administered every 4 weeks for 24 months, and patients underwent bone marrow aspiration at baseline, and 12 and 24 months of ZOL. Complete DTC response (<4 DTC/mL), serial CTCs, survival, recurrence, and toxicity were determined. Forty-five patients received ZOL. Median baseline DTC was 13.3/mL. Significant reduction in median DTC occurred from baseline to 12 months, and 24 months. Complete DTC response was seen in 32% at 12 months, and 26% at 24 months. Nine patients developed recurrence. Baseline DTC > 30/mL and CTC > 0.8/mL were significantly associated with recurrence and death. Serial reduction in DTCs occurred. Higher baseline DTC > 30/mL and CTC > 0.8/mL correlated with recurrence and death.