Absence Of Circulating Tumor Cells Research Articles

Increased Levels of Circulating Plasma Cells in Patients with Newly Diagnosed Multiple Myeloma Are Independently Associated with Poor Prognosis

The presence of circulating tumor cells (CTCs) has long been suggested as a valuable prognostic biomarker in Multiple Myeloma (MM). Recently, increased baseline CTC levels in patients with newly-diagnosed MM (NDMM) have been associated with adverse outcomes in the GEM2012MENOS65/GEM2014MAIN and FORTE trials. Since January 2017, we have been evaluating the presence of CTCs utilizing Next-generation Flow cytometry (NGF) with a median limit of detection (LOD) reaching 2x10-6. NGF assessment has been performed according to the EuroFlow guidelines for sample preparation, antibodies, cytometer settings and analysis of data. Currently, we have analyzed 525 matched BM and PB samples from NDMM patients and have found clonal plasma cells in 100% of BM and 89.1% (468/525) of PB samples respectively. Patients presented with ISS III/R-ISS III, high-risk cytogenetics, serum β2 microglobulin above median and hemoglobin levels ≤ 8.5 g/dL had increased CTC levels. Inversely, the absence of CTCs or their low prevalence (<10-5) was associated with an increased normal plasma cell compartment within the BM (R2=0.82, P < .0001). No association was detected between the CTC number and the therapeutic response to induction treatment in accordance with previous reports. Nevertheless, over a median follow-up monitoring of 42 months (range: 3-66 months), a running log-rank test with a step increase of 0.1% CTCs, highlighted an optimal cut-off point for PFS risk assessment at the level of 2x10-4. In the multivariable analysis, NDMM patients with CTCs above this cut-off showed a 2.2-fold higher risk of progression which was independent from ISS, induction scheme and baseline cytogenetics (HR: 2.2, 95% CI: 1.24 - 3.28, P< .001). Our large number of matched samples allowed for a phenotypic comparison between BM clonal cells and CTCs. The majority of patients with detectable CTCs (86%) showed a matched phenotypic profile of aberrant plasma cell in the two sites. However, 66 patients showed phenotypic discrepancies based on one of the following patterns: i) all phenotypic subsets were present in both BM and PB but with significantly altered ratios (≥20% of relative prevalence) for at least two concomitant subsets; ii) presence of ≥ 1 phenotypic subsets (with a minimum relative prevalence of 20% of all clonal cells) only in the BM; and iii) presence of ≥ 1 phenotypic subsets only in the PB. Remarkably, patients with phenotypic discrepancies had significantly higher CTC levels than those with a phenotypic agreement on the two sites (P < .001), together with signs of a more diffuse disease pattern, as evidenced by the imaging results. It is likely that these patients may share a patchy BM infiltration (and/or even extramedullary disease) and accumulate circulating clonal cells from various sites (thus leading to increased tumor burden) with a spatial clonal heterogeneity, which, as a total, may differ from a specific phenotype derived from a particular BM site. The biological differences among patients with differential baseline CTCs expand beyond the tumor cells. Performing a deep phenotypic approach for the identification of 32 distinct immune subsets, we analyzed the immune profile of both ΒΜ and PB in NDMM patients differing to their CTC levels by two log decimals. Patients with CTCs ≥ 5x10-3 had substantially increased levels of total T cells (especially CD8+), NK cells, tumor associated macrophages (TAMs) and an elevated ratio of memory to naïve B cells (P < .0001 for all subsets) in their BM microenvironment than those with less than 5x10-5 CTCs. The same differences, though with weaker statistical significance, applied also in PB, where, we could also identify a clear immune signature with characteristics of tumor suppression and T cell exhaustion for NDMM with the high CTC burden. Altogether, our results confirm the negative and independent prognostic impact of increased CTC levels in the NDMM and further imply its relevance in the real-world setting to establish improved risk-stratification models. Moreover, since the liquid biopsy is a better representative of the entire tumor load than a tissue biopsy sample, the analysis of CTCs may serve as the new hallmark for the real-time evaluation of a patient's disease and/or immune status.

Factors of innate immunity in patients with colon cancer with different levels of circulating tumor cells.

e15501 Background: The purpose of this study was to demonstrate the importance of circulating tumor cells (CTCs) in the formation of immunosuppression in colon cancer. Methods: 200 patients with stage II-IV colon cancer underwent surgery as the first stage of treatment. Blood levels of CTCs were determined before surgery by flow cytometry using the CellSearch method (the sample was considered positive with CTCs &gt; 3), as well as some indicators of innate immunity (NK cells, neutrophilic and monocytic phagocytosis). Results: Regardless of the stage, patients with CTCs had statistically significantly lower levels of NK lymphocytes (16.8±1.9 versus 22.3±1.8%, p≤0.05) compared with the absence of CTCs; on the contrary, levels of NKT cells in this group were higher than in the absence of CTCs (8.8±0.9 versus 5.0±1.0%, p≤0.05). The presence of CTCs was accompanied by higher levels of CD16dim56bright cells (13.1±3.2 versus 5.9±1.0% p≤0.05) with a lower content of CD16+56dim (82.5±3.6 versus 90.4±0.8%), and levels of perforin and granzyme were similar. The presence of CTCs was characterized by a higher percentage of phagocytic monocytes in the Phagotest test, as well as a higher percentage of monocytes and neutrophils capable of developing oxidative burst upon fMLF stimulation in the Phagoburst test (10.8±3.3 versus 3.2±1.5% and 5.1 ±0.8 vs. 2.0±1.1%, respectively; p≤0.05). A separate analysis of phagocytosis indicators by disease stages revealed that the presence of CTCs in patients was accompanied by stimulation of phagocytosis in local tumors and inhibition in advanced disease, however, in the latter case, the ability of granulocytes and monocytes to generate reactive oxygen species (ROS) was preserved and even increased. Conclusions: The presence of CTCs in patients with colon cancer is characterized by a redistribution of natural killer subpopulations with an increase in the blood levels of NKT cells, some of which have immunosuppressive activity, due to a decrease in NK cells, and an increase in CD16dim56bright and a decrease in CD16+56dim, apparently, indicates disturbance of their maturation. The established changes in the presence of CTCs indicate the inhibition of antitumor properties of the NK cell and phagocytic components of innate immunity in tumor cell circulation. The N-formylpeptide fMLF is known as a powerful neutrophil chemoattractant, stimulator of their migration and cytokine production, which plays a role in the development of inflammatory bowel diseases. The growth-promoting activity described for the similar antimicrobial protein LL-37 can be mediated through neutrophil migration and ROS production. Thus, the presence of CTCs has a negative impact on the parameters of NK cell and phagocytic components of innate cellular immunity in patients with colon cancer, which can serve as one of the strategies for survival and dissemination of the tumor.

Circulating tumor cells as a biomarker for monitoring: Disease progression, treatment response, and minimal residual disease.

e15021 Background: To analyze the role of Circulating tumor cells (CTC) as a confirmatory personalized biomarker for monitoring the disease progression, disease burden, and minimal residual disease in epithelial origin cancers. Methods: In this retrospective study, 127 patients with colorectal, breast, and ovarian cancer at stage III and IV were analyzed. The patients were at various stages of intensive chemo and radiotherapy while the CTCs were isolated and enumerated from 1.5 ml of blood. The decision to continue chemotherapy or change to oral metronomic therapy was based on the presence of circulating tumor cells in Stage III. While in stage IV, serial measurement of CTC guided therapy. CTCs were isolated using OncoDiscover platform possessing EpCAM antibody based immunomagnetic targeting of magnetic nanoparticles after RBC lysis. CTCs were imaged and identified as CK18+ and CD45- cells showing a well-defined nucleus using a motorized fluorescence microscope operational with a monochrome camera. CTCs were enumerated using automated image analysis software and counts were expressed as number per 1.5 ml of blood. Results: In this retrospective study we analyzed blood sample from 127 patients with the advanced stage epithelial cancers (breast- 50 %, ovarian -27 %, colorectal- 23 %) for the presence of CTCs. Amongst those, 52 % showed the presence of CTCs (breast- 52 %, ovarian -46 %, colorectal- 58 %). The CTC count ranged between 1-5 / 1.5 ml of blood with mean and median value of 2 and 1. Among the CTC positive population, majority had CTC count of 1 (44.4 %), while more than 2 CTCs were observed in 11 % of population. CTC clusters were detected in 13 % of population which predominantly were stage IV patients. 67 % among the follow up patients showed decrease in CTC count from the baseline due to the prescribed treatment, while 22 % patients showed increase in CTC count from the baseline. 11 % patients did not show change in CTC count from the baseline. When CTCs count was investigated as an independent variable to monitor the therapeutic response, it correlated well with the positive or negative outcome. In few representative cases, the reduction of CTC number from the basal value was indicative of an effective treatment. Exceptionally, in a representative colorectal cancer case, PET showed no primary as well secondary tumor burden, but the presence of CTCs in blood led further investigating an abdominal MRI that indicated multiple liver lesions suggesting micro-metastasis. Subsequent to SIRT treatment, the patient showed complete tumor regression and absence of CTCs in peripheral blood. Conclusions: Our data suggest that CTC can serve as a dynamic intermittent biomarker for monitoring the disease progression in advanced stages and assess the therapeutic response, thus emphasizing the role of CTCs in personalized cancer management.

Peripheral blood levels of tumor-infiltrating lymphocytes (TILs) and circulating tumor cells (CTCs) in patients with colorectal cancer.

e15510 Background: Tumor is a structure where malignant cells interact, among others, with cells of the adaptive and innate immune systems largely determining the tumor microenvironment. The role of TILs in the disease prognosis has been shown. The amount of CTCs is one of the factors that significantly affect the risk and rate of metastasis. The purpose of the study was to assess an association between TILs and CTCs in the peripheral blood of patients with various stages of colorectal cancer (CRC). Methods: The study included 299 patients (aged 42-86 years, mean age 64.2±1.7) with stage II-IV CRC T1-4N0-2M0-1. TILs were identified in tumor material after standard histological processing. Lymphocytes were counted per 100 epithelial cells in 5 fields of view at a magnification of x400; the result was expressed as a percentage ( &lt; 5% weak, 5-30% moderate, &gt;30% strong). The numbers of CTCs were measured in the peripheral blood using the Veridex CellSearch system (Janssen), taking into account the expression of epithelial cell adhesion markers EpCAM, cytokeratins 8,18,19 and absence of the CD45 expression. The blood sample was evaluated according to the following criteria: 0 CTCs, 1-3 CTCs, and more than 3 CTCs. Statistical analysis of results was performed in the Statistica 13.0 program (StatSoftInc., USA). Results: Weak lymphocytic infiltration was detected in 32.8%, moderate - in 48.1%, strong - in 19.1% of cases. CTCs were detected in 62.9% cases (in 188 of 299 patients). The percentages of patients with 1-3 CTCs and with &gt;3 CTCs were equal - 50% (94 of 188). CTCs were not registered in 37.1% cases (111 of 299). The absence of CTCs was noted equally often in moderate and strong lymphocytic infiltration – 43.7% and 43.8%. The presence of tumor cells in the peripheral blood was most often detected in weak lymphocytic infiltration, being 1.4 times more frequent than in moderate and strong infiltration (76.5% vs. 56.3% and 56.2%) (p = 0.019, c2= 11.890). Conclusions: The study demonstrated a significant relationship between the level of CTCs and the intensity of lymphocytic infiltration in the tumor (p≤0.05), which can be used as a new prognostic approach.

Circulating Tumor Cells and Bevacizumab Pharmacokinetics during Neoadjuvant Treatment Combining Chemotherapy and Bevacizumab for Early Breast Cancer: Ancillary Analysis of the AVASTEM Trial.

Simple SummaryWe recently published the results of the AVASTEM study, in which we explored the impact of the addition of an angiogenesis inhibitor (bevacizumab) to standard pre-operative chemotherapy for breast cancer. In this work, we aimed to identify biological parameters correlated to prognosis and treatment efficacy. To do so we explored if circulating tumor cells (CTCs), that are cells released by the tumor and that can be detected in the bloodstream of a patient; can predict the outcome of the women treated in this study. We also analyzed if bevacizumab concentration in the blood during treatment was associated with outcome, i.e., response to treatment and survival. We observed that CTCs detection before treatment initiation is associated with survival but was not correlated to local response to treatment. We moreover found that CTC status after three weeks of chemotherapy was not correlated to outcome as well as bevacizumab levels before and during treatment. However, bevacizumab concentration tended to be associated with an increase of hematological toxicities during the study. We thus show in this work that CTCs detection at baseline is prognostic for patients with breast cancer receiving a pre-operative chemotherapy-bevacizumab combination, and that this prognostic value was independent of tumor response.The phase II AVASTEM trial explored the impact of chemotherapy-bevacizumab combination on breast cancer stem cells in the neoadjuvant setting. We aimed to identify biological features associated with preoperative chemotherapy efficacy and prognosis by analyses of circulating tumor cells (CTCs) and bevacizumab pharmacokinetics (PK). The main objective was to assess the prognostic (relapse-free survival and overall survival) and predictive (pathological complete response, pCR) values of CTCs (CellSearch technology) and bevacizumab PK (ELISA). Seventy-five patients were included. Out of them 50 received bevacizumab-chemotherapy and 25 received chemotherapy alone. CTC results were available for 60 patients and PK data for 29 patients in the experimental arm. The absence of CTC at inclusion was correlated to better outcome. Five-years overall survival (OS) was 91% for CTC-negative patients vs. 54% for CTC-positive cases (HR = 6.21; 95%CI (1.75–22.06), p = 0.001, log-rank test). Similar results were observed for RFS with 5 y-RFS of 78% vs. 44% (HR = 3.51; 95%CI (1.17–10.52), p = 0.017, log-rank test). However, CTC status at baseline was not predictive of pCR (p = 0.74). CTC status after one cycle was not a significant prognostic factor (HR = 1.56; 95%CI (0.19–12.67); p = 0.68 for OS and HR = 2.76; 95%CI (0.60–12.61); p = 0.17 for RFS, log-rank test). Bevacizumab serum levels could not predict pCR and survival. PK values were not associated with treatment-related toxicities. In conclusion, CTCs detection at baseline is a prognostic marker for breast cancer receiving a neoadjuvant chemotherapy-bevacizumab combination independently of tumor response.

CELL MEDIATED IMMUNITY IN PATIENTS WITH STAGE II–IV COLORECTAL CANCER WITH OR WITHOUT CIRCULATING TUMOR CELLS

Nowadays, circulating tumor cells (CTCs) are considered to be one of the most important mechanisms of tumor dissemination. Detection of CTCs in patients` blood is estimated as a prognostic factor for various tumors including colorectal cancer (CRC). However, CTCs may also be a source of tumor antigens capable of inducing both immune response and tolerance and participating in «immmunoediting». The aim of the study was to assess the parameters of cell-mediated immunity in patients with stage IIIV CRC with respect to the presence or absence of CTCs. Materials and Methods . We studied the parameters of cell-mediated immunity in 60 patients with stage IIIV CRC with respect to the presence or absence of CTCs. Before treatment, we evaluated the CTC levels in patients’ blood using CellSearch System™ and lymphocyte subsets: Т-В-NК-cells, T-reg, CD4+ and CD8+ expressing markers of activation (CD69+, СD38+, CD25+, HLA-DR+ СD95+); naïve and memory T-lymphocytes (CD45RA-/CD45RO+); NК-cells expressing CD335, perforin and granzyme B using flow cytometry (FACSCantoII, BD). Results . A difference in the immunologic parameters between patients with CTCs and without CTCs depending on the stage of CRC was found. In СTС-positive patients with locally-advanced CRC, increase in the parameters of innate immunity (CD335+ NK-cells, neutrophils` respiratory burst) and activated Th (CD38+, CD25+, HLA-DR+) was found, while in СTС-positive patients with generalized CRC, suppression of cytotoxic lymphocytes of both innate (CD56/16+) and adaptive (CD8+CD25+) immunity was observed, which is, apparently, an unfavorable prognostic factor. Conclusion . The presence of CTC in CRC patients is accompanied by some immunologic changes rather stimulating Thlink and innate immunity factors in II-III stages and doubtlessly suppressive in patients with IV stage.

Factors associated with extended survival for patients with platinum-resistant ovarian cancer treated with modified vaccinia oncolytic virotherapy.

e17070 Background: VIRO-15 phase IB trial included 11 patients (pts) with platinum-resistant ovarian cancer (PROC), extensive tumor burden and a median of 5 prior lines of therapy who were given intra-peritoneal Olvi-Vec (GL-ONC1), a modified vaccinia oncolytic virus (OV). Four pts had apparent clinical benefit with &gt; 5 mos progression-free survival (PFS) following OV. This analysis aimed to determine factors that predict clinical benefit from OV. Methods: Comparative analyses included: anti-vaccinia neutralizing antibody (NA) as a measure of immune-competence, virus-encoded glucuronidase activity (GA) indicating viral replication, tumor shrinkage by RECIST 1.1, tumor burden (serum LDH), PD-L1 status, Prognostic Nutritional Index (PNI), absolute lymphocyte count, C-reactive protein, albumin, ECOG performance score (PS), no. of prior lines of therapy and platinum therapies, BRCA status, CA125 tumor marker, &amp; circulating tumor cells (CTCs). Results: Mean age was 66.3±9.3 years and BMI 24.8±4.7 kg/m2. Median prior chemotherapy lines = 5 (range 2-10), median prior platinum lines = 3 (range 2-6), and 9 pts had prior Avastin. Following OV, 4 pts (Group A) had mean PFS 10.9±5.1 (range 5.4-16.4) mos compared to 7 pts (Group B), with mean PFS 2.4±1.1 (range 1.3-4.1) mos ( p&lt; 0.05). Mean OS for Group A was 21.7±8.2 (range 7.8-28.3) mos vs 3.6±1.5 (range 1.6-6.2) mos for Group B ( p&lt; 0.05). 3 Group A pts are alive with PS 0, and one with stable disease died at 8 mos from pulmonary embolism. Factors that predicted clinical benefit were: i) PNI [mean 49.0±5.7 vs 42.1±4.3 ( p&lt; 0.05)], ii) Week-5 CA125 values &lt; Week-2 [4/4 vs 0/7 (p &lt; 0.01)], iii) absence of CTC [3/4 vs 1/7 pts ( p&lt; 0.05)]. Baseline PD-L1 expression and BRCA status were not predictive markers. Conclusions: Factors associated with clinical benefit using GL-ONC1 monotherapy in PROC include PNI &gt; 44.5, absence of CTCs, and Week-5 CA125 less than Week-2 levels. Absent these factors, cytotoxic therapy should be considered by Week-6 following GL-ONC1. Three patients are currently alive at 22.8-28.2 mos, following additional therapies. A multi-institutional phase II trial is currently enrolling. Clinical trial information: NCT02759588.

Denosumab treatment is associated with the absence of circulating tumor cells in patients with breast cancer

BackgroundThe presence of circulating tumor cells (CTCs) in patients with breast cancer correlates to a bad prognosis. Yet, CTCs are detectable in only a minority of patients with progressive breast cancer, and factors that influence the abundance of CTCs remain elusive.MethodsWe conducted CTC isolation and enumeration in a selected group of 73 consecutive patients characterized by progressive invasive breast cancer, high tumor load and treatment discontinuation at the time of CTC isolation. CTCs were quantified with the Parsortix microfluidic device. Clinicopathological variables, blood counts at the time of CTC isolation and detailed treatment history prior to blood sampling were evaluated for each patient.ResultsAmong 73 patients, we detected at least one CTC per 7.5 ml of blood in 34 (46%). Of these, 22 (65%) had single CTCs only, whereas 12 (35%) featured both single CTCs and CTC clusters. Treatment with the monoclonal antibody denosumab correlated with the absence of CTCs, both when considering all patients and when considering only those with bone metastasis. We also found that low red blood cell count was associated with the presence of CTCs, whereas high CA 15-3 tumor marker, high mean corpuscular volume, high white blood cell count and high mean platelet volume associated specifically with CTC clusters.ConclusionsIn addition to blood count correlatives to single and clustered CTCs, we found that denosumab treatment associates with most patients lacking CTCs from their peripheral circulation. Prospective studies will be needed to validate the involvement of denosumab in the prevention of CTC generation.

Abstract 4209: First-line doublet chemotherapy for mTNBC: circulating tumor cell analysis of the tnAcity trial

Abstract Introduction Circulating tumor cells (CTCs) have been shown to be prognostic in patients (pts) with metastatic breast cancer (MBC) (Pukazhendhi, Gluck, J Carcinog. 2014). The tnAcity trial evaluated the efficacy/safety of 3 chemotherapy combination regimens (nab-P/carboplatin [C], nab-P/gemcitabine [G], or G/C) as first-line treatment for pts with mTNBC. nab-P/C resulted in a significantly longer PFS &amp; numerically higher ORR vs nab-P/G or G/C (Yardley. SABCS 2016; manuscript in process). CTC levels were assessed at baseline (BL) &amp; during treatment to determine correlation with clinical benefit. Methods Pts with pathologically confirmed mTNBC &amp; no prior cytotoxic chemotherapy for MBC received (1:1:1) nab-P 125 mg/m2 with C area under the curve (AUC) 2, nab-P 125 mg/m2 with G 1000 mg/m2, or G 1000 mg/m2 with C AUC 2, all given d1 &amp; 8 q3w. Primary endpoint: investigator-assessed PFS. Secondary endpoints included ORR &amp; OS; CTC enumeration was a prespecified exploratory objective. CTC levels, assessed (CELLSEARCH®) at BL &amp; start of cycles 3 &amp; 5 (post-BL), were grouped as follows: 0 CTCs/7.5 mL blood at BL (−−), ≥ 1 CTCs/7.5 mL blood at BL &amp; post-BL (++), &amp; ≥ 1 CTCs/7.5 mL blood at BL &amp; clearance of CTCs in ≥ 1 post-BL measurement (+−). Results In total, 126 pts were included: 48, 24, &amp; 54 in the −−, ++, &amp; +− groups, respectively. Mean BL CTC levels for the ++ &amp; +− groups were 55 &amp; 66 CTCs/7.5 mL blood. Pts with BL CTCs of ≥ 1 vs 0 had numerically similar median PFS (7.0 vs 5.9 mo; HR 1.45 [95% CI 0.93 - 2.25]) &amp; OS (15.0 vs 16.0 mo; HR 0.90 [95% CI 0.57 - 1.42]) &amp; higher ORR (64% vs 44%). Mean cycle 3 &amp; 5 CTC levels in the ++ group were 17 &amp; 111 CTCs/7.5 mL blood. Pts in the −− &amp; +− groups had longer PFS vs the ++ group (median 5.9, 8.5, &amp; 4.7 months). Similar improvements in OS &amp; ORR were noted (Table). Conclusions Absence of CTCs at BL &amp; during treatment &amp; clearance of CTCs from BL at least once during treatment were generally associated with improved efficacy outcomes in pts with mTNBC treated with combination chemotherapy. Table. Outcomes by Change in CTC Level from BaselineGroupOutcome−− n = 48+− n = 54++ n = 24PFS, median, mo HR (95% CI)5.9 0.60 (0.34-1.06)a8.5 0.30 (0.17-0.54)a4.7OS, median, mo HR (95% CI)16.0 0.40 (0.22-0.73)a17.8 0.35 (0.20-0.62)a9.8ORR, %43.879.629.2CR6.316.74.2PR37.563.025.0SD35.420.454.2PD16.7—16.7NE4.2——CR, complete response; HR, hazard ratio; NE, not evaluable; ORR, overall response rate; OS, overall survival; PD, progressive disease; PFS, progression-free survival; PR, partial response; SD, stable disease. a vs ++ group. Citation Format: Minetta C. Liu, Wolfgang Janni, Vassilis Georgoulias, Denise A. Yardley, Nadia Harbeck, Xin Wei, Desmond McGovern, Robert Beck. First-line doublet chemotherapy for mTNBC: circulating tumor cell analysis of the tnAcity trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4209.

Clinical impact of circulating tumor cells and therapy response in pancreatic cancer

BackgroundAmong gastrointestinal cancers, the prognosis of pancreatic cancer is one of the poorest, with a large number of patients being diagnosed with unresectable tumors at the first visit to a doctor. The aims of the present study were to investigate the circulating tumor cells (CTC) in peripheral blood in order to assess their clinical significance in patients with pancreatic cancer. MethodsSixty-five patients with advanced pancreatic cancer were enrolled. Borderline resectable pancreatic tumor patients were 9, and Unresectable patients were 56. The CellSearch system was used to isolate and enumerate CTCs. ResultsCTCs were identified in 21 out of 65 patients (32.3%) with only unresectable tumors. The overall survival rate was significantly lower in unresectable patients with than in those without CTCs (P = 0.0051). CTC positivity was significantly higher in patients with than in those without liver metastasis. A multivariate analysis identified the presence or absence of CTCs as an independent prognostic factor. Follow-up blood specimens were obtained from 40 patients treated with chemotherapy or chemoradiotherapy. The incidences of CTC positivity at three months after beginning of treatments in patients with progressive disease and stable disease or a partial response were 45.4% and 24.1%, respectively. The overall survival rate was significantly lower in patients with than in those without CTCs even after treatments (P = 0.045). ConclusionCTC numbers represents a useful tool for predicting prognoses and therapeutic responses to chemotherapy among patients with advanced pancreatic cancer.

Thymidylate synthase expression in circulating tumor cells: a new tool to predict 5-fluorouracil resistance in metastatic colorectal cancer patients.

Thymidylate synthase (TYMS) is an important enzyme for 5‐fluorouracil (5‐FU) metabolism in metastatic colorectal cancer (mCRC) patients. The search for this enzyme in circulating tumor cells (CTCs) can be a powerful tool to follow‐up cancer patients. mCRC patients were enrolled before the beginning of 5‐FU‐based chemotherapy. The blood was filtered on Isolation by Size of Epithelial Tumor Cells (ISET), and the analysis of TYMS expression in CTCs was made by immunocytochemistry. Additionally, we verified TYMS staining in primary tumors and metastases from the same patients. There were included 54 mCRC patients and 47 of them received 5‐FU‐based chemotherapy. The median CTCs number was 2 per mL. We were not able to analyze immunocytochemistry in 13 samples (9 patients with absence of CTCs and 4 samples due to technical reasons). Therefore, TYMS expression on CTCs was analyzed in 34 samples and was found positive in 9 (26.5%). Six of these patients had tumor progression after treatment with 5‐FU. We found an association between CTC TYMS staining and disease progression (DP), although without statistical significance (P = 0.07). TYMS staining in primary tumors and metastases tissues did not have any correlation with disease progression (P = 0.67 and P = 0.42 respectively). Patients who had CTC count above the median (2 CTCs/mL) showed more TYMS expression (P = 0.02) correlating with worse prognosis. Our results searching for TYMS staining in CTCs, primary tumors and metastases suggest that the analysis of TYMS can be useful tool as a 5‐FU resistance predictor biomarker if analyzed in CTCs from mCRC patients.

P1-06-12: Circulating Tumor Cells (CTC) Monitoring during Phase II Study with Lapatinib (L) and Capecitabine (C) in Patients with Brain Metastases from HER2−Positive (+) Metastatic Breast Cancer (MBC) before Whole Brain Radiotherapy (WBR): LANDSCAPE Study.

Abstract Background: Decrease of CTC level during treatment in MBC has been reported as an independent prognostic and predictive factor of patients’ outcome. Monitoring CTC in addition to clinical response criteria is currently evaluated in early clinical trials in various cancer types. We sought to evaluate the clinical interest of peripheral blood CTC for patients included in the LANDSCAPE study which assessed the efficacy of upfront systemic treatment with L+C for newly diagnosed brain metastasis. Methods: This analysis is a preplanned secondary endpoint of the LANDSCAPE study. Eligible pts had HER2+ MBC with BM not previously treated with WBR, C or L. Pts received L1250 mg/day and C2000 mg/m2/day, days 1–14, every 21 days. The primary endpoint was a centrally assessed CNS objective response (CNS-OR) defined as a ≥50% volumetric reduction of CNS lesions in the absence of increasing steroid use, progressive neurologic symptoms or progressive extra-CNS disease. CTC were detected in 7.5 ml of blood using the CellSearchSystem™, combining EpCAM immunomagnetic selection (IMS) followed by anti-cytokeratin (A45B/B3) fluorescently staining for CTC at baseline and at day (D) 21, before cycle 2. Results: From 04/2009 to 08/2010, 45 pts were enrolled, 41 were evaluable for CTC at baseline and 38 at D21. Median age was 56 (range 35 to 79). PS was &amp;gt;1 only in 2 pts. At baseline, 20/41 (48.8%) pts had ≥ 1CTC and 9 (22%) ≥ 5CTC (range 1–301, median 3). CTC were detected in pts with (18/37) or without disease outside SNC (2/6) (p=0.63). At a median follow-up of 10 months (range 2.9−16.5), median TTP was 6.0 months [95% CI 4.9; 7.4] vs. 4.3 [2.8; 5.9] months for pts without and with CTC at baseline respectively (p=0.14). After 21 days of treatment, a disappearance of CTC was observed in 11pts (31%). At D21, only 7 (18.4%) pts had ≥ 1CTC and 3 (8%) ≥ 5 CTC (p=0.006, D21 vs. baseline). In 43 evaluable pts, CNS-OR rate was 67% (95%CI 51–81), with a median time from inclusion to response of 1.8 month. Absence of CTC was not correlated with CNS-OR rate at baseline (17/21 (81%) vs. 11/19 (58%), NS). Strikingly, remaining positivity for CTC at D 21 (≥ 1CTC) was correlated with a poor response rate in CNS: 2/6 (33.3%) vs. 25/31 (80.6%) in pts with 0 CTC, p=0.03. Conclusions: Early decrease (at D 21) in CTC level is correlated with a high response rate in newly diagnosed BM to L + C and underlines the predictive value of this blood marker in MBC pts even for brain metastasis. Longer follow-up is needed to assess its prognostic value under antiHER2 targeted therapy. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-06-12.

Circulating Tumor Cells and EpCAM Expression in Neuroendocrine Tumors

Neuroendocrine tumors (NET) are heterogeneous tumors with widely variable survival. It is unknown whether they express EpCAM (epithelial cell adhesion molecule) and thus whether NET circulating tumor cells (CTC) are detectable. We systematically investigated EpCAM expression and CTC detection in patients with metastatic NETs and evaluated the potential of CTCs to predict radiological progression. EpCAM protein expression was evaluated in 74 samples of formalin-fixed, paraffin-embedded NET tissue by immunohistochemistry. Seventy-nine patients with metastatic NETs (42 midgut, 5 unknown primary, 19 pancreatic, 13 bronchopulmonary) had blood samples drawn for CTC isolation and enumeration utilizing the CellSearch platform. Patients were classified as having progressive or nonprogressive disease on the basis of serial imaging. Strong homogeneous, membranous EpCAM expression was observed in all ileal (n = 26) and pancreatic NETs (n = 16), whereas variable EpCAM expression was observed in bronchopulmonary NETs (n = 13). Forty-three percent of midgut and 21% of pancreatic NETs had CTCs detected with a range of 0-62 and 0-11, respectively. The absence of CTCs was strongly associated with stable disease (P < 0.001). There was a moderate correlation between CTC levels and urinary 5-hydroxyindole acetic acid (r = 0.5, P = 0.007) and between CTC levels and burden of liver metastases (B = 8.91, P < 0.001). There was no or low correlation between CTC levels and Ki-67 (r = 0.08, P = 0.59) and serum chromogranin A (r = 0.246, P = 0.03). This is the first systematic analysis showing EpCAM expression and CTC detection in NETs. CTCs seem to be associated with progressive disease and may provide useful prognostic information given the variable survival rates in these tumors.

Assessment of circulating tumor cells in breast cancer patients undergoing neoadjuvant chemotherapy

10079 Background: Circulating tumor cells (CTCs) are a valuable prognostic factor in metastatic breast cancer, suggesting that CTCs, if present, may be clinically useful in other breast cancer (BC) settings. This study prospectively evaluated CTCs before and after neoadjuvant chemotherapy (NACT) in patients with operable breast cancer. Methods: 7.5 or 30ml of blood were drawn in CellSave tubes from 26 Pts about to receive NACT (docetaxel + capecitabine followed by adriamycin + cytoxan) followed by surgery. CTC analysis is being performed at multiple time points. Data presented are from baseline (prior to first dose), post-NACT, and 3 months after surgery. CTCs were measured by immunomagnetic separation and automated fluorescent microscopy using the CellSearch System (Veridex/Immunicon Corp). Results: Baseline CTCs: For the first 11 pts CTCs were analyzed from 7.5ml of blood. 36% (4/11) had ≥1 CTC, 27% (3/11) had ≥2 CTCs. Of pts with detectable CTCs, the mean was 2.75 CTCs/7.5ml (range 1–4). To improve baseline sensitivity, 30ml blood was drawn from the subsequent 15 pts. One sample was not evaluable. 50% (7/14) had ≥1 detectable CTC and 29% (4/14) had ≥2 CTCs. Of pts with detectable CTCs, the mean was 3.0 CTCs/30ml (range 1–10). CTCs post-neoadjuvant therapy: All 26 pts had 30ml of blood drawn for CTC analysis. 27% (7/26) had ≥1 CTC, and 8% (2/26) had ≥2 CTCs. Using as threshold of ≥2 CTCs to define elevated, CTCs post-chemotherapy were compared to the pathologic complete response (pCR). Sensitivity was 10% (2 of 18 pts with residual disease had elevated CTCs). Specificity was 100% (0 of 7 pts with a pCR had elevated CTCs). This correlated to a positive predictive value of 100% and a negative predictive value (NPV) of 28%. CTCs 3 months after surgery: Of 21 pts analyzed, only one pt (5%) had a single CTC. Long-term follow-up blood collection is ongoing. Conclusions: CTCs are detectable in ∼30% locally advanced BC. All patients with CTCs after NACT had residual disease at surgery, and no CTCs were detected in patients with pCR. However, the absence of CTCs after NACT did not predict pCR. Pts will be followed to determine if CTCs correlate with recurrence and survival. [Table: see text]

Jaw reflex in Friedreich ataxia.

Twenty-one patients with Friedreich ataxia were examined and found to have a brisk jaw reflex. This previously unreported clinical finding contrasts with the impairment of tendon reflexes in the limbs and should not rule out the diagnosis of Friedreich ataxia.