Value Of Circulating Tumor Cells Research Articles

Prognostic value of circulating tumor cells in patients with pancreatic cancer: a meta-analysis

Increasing scientific evidences suggest that circulating tumor cells (CTC) in peripheral blood may be a powerful predictor of survival in patients with pancreatic cancer. However, many existing studies have yielded inconclusive results. This meta-analysis aims to assess the prognostic value of CTC in patients with pancreatic cancer. An extensive literary search for relevant studies was conducted on PubMed, Embase, Web of Science, Cochrane Library, CISCOM, CINAHL, Google Scholar, CNKI, and CBM databases from their inception through July 1, 2013. The meta-analysis was then performed using the Stata 12.0 software. Crude hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated under a fixed or random effect model. Nine cohort studies were included in this meta-analysis with a total of 623 pancreatic cancer patients. This number included 268 CTC-positive patients and 355 CTC-negative patients. Our meta-analysis revealed that patients in the CTC-positive group were significantly associated with poor progression-free survival (PFS) (HR = 1.89, 95% CI = 1.25-4.00, P < 0.001). Furthermore, pancreatic cancer patients in the CTC-positive group also showed worse overall survival (OS) than those in the CTC-negative group (HR = 1.23, 95% CI = 0.88-2.08, P < 0.001). Subgroup analysis by ethnicity indicated that CTC-positive patients had poor OS among both Asian and Caucasian populations (all P < 0.05). Further subgroup analyses by detection and treatment methods also suggested that CTC-positive patients showed worser OS than CTC-negative patients in the majority of subgroups (all P < 0.05). No publication bias was detected in this meta-analysis. In conclusion, our meta-analysis suggests that CTC-positive pancreatic cancer patients may have worser PFS and OS than CTC-negative patients. Detection of CTC in peripheral blood may be a promising biomarker for the detection and prognosis of pancreatic cancer.

716 Differential Survival in Patients With Hepatitis B Virus-Related Hepatocellular Carcinoma (HBV/HCC) Compared to Hepatitis C Virus-Related Hepatocellular Carcinoma (HCV/HCC)

Background/Aims: Detection of circulating tumor cells (CTC) is associated with poor progression free and overall survival in patients with breast, prostate, and colon cancer. There is limited information about the prognostic value of CTC in patients with cholangiocarcinoma (CCA). The aim of this study are (1) to quantify circulating tumor cells in the peripheral blood of patients with CCA; and (2) to test the hypothesis that the presence of circulating tumor cells is associated with larger tumor burden of CCA and poor overall survival. Methods: A total of 45 patients with CCA seen at Mayo Clinic Rochester were prospectively enrolled between June 2010 and September 2012. 10 ml peripheral blood was drawn into CellSave Preservative Tubes. Blood samples were processed within 96 hours after the blood draw. The CellSearch system by Veridex was used for the capture, enrichment, identification and enumeration of CTC of epithelial origin in 7.5 ml of peripheral blood from the patients. The CellSearch system has an estimated sensitivity of approximately 20-30% for detecting CTC at a prognostic level . The association between baseline characteristics and detection of CTC was analyzed. Overall survival was estimated by the Kaplan Meier method and compared using the Log Rank test. Results: The mean age of patients was 61 and 29 (64%) patients were male. CTC were detected in 13 (28%) patients. Patients with CTC tended to have larger tumor size, more tumor nodules, a higher CA19-9 level, increased CEA, lymph node involvement, and metastatic disease compared to patients without CTC. (Table) There was no significant association between CTC and demography (age, gender, and race) or underlying liver dysfunction . There was a trend towards poorer survival in patients with CTC compared to patients without CTC (p=0.09). Conclusion: CTC are detectable in patients with cholangiocarcinoma. The presence of CTC was associated with tumor burden and metastatic cancer. The prognostic implications of CTC in patients with CCA need further validation in a larger patient group.

631 Circulating Tumor Cells Are Associated With More Advanced Disease in Cholangiocarcinoma

Background/Aims: Detection of circulating tumor cells (CTC) is associated with poor progression free and overall survival in patients with breast, prostate, and colon cancer. There is limited information about the prognostic value of CTC in patients with cholangiocarcinoma (CCA). The aim of this study are (1) to quantify circulating tumor cells in the peripheral blood of patients with CCA; and (2) to test the hypothesis that the presence of circulating tumor cells is associated with larger tumor burden of CCA and poor overall survival. Methods: A total of 45 patients with CCA seen at Mayo Clinic Rochester were prospectively enrolled between June 2010 and September 2012. 10 ml peripheral blood was drawn into CellSave Preservative Tubes. Blood samples were processed within 96 hours after the blood draw. The CellSearch system by Veridex was used for the capture, enrichment, identification and enumeration of CTC of epithelial origin in 7.5 ml of peripheral blood from the patients. The CellSearch system has an estimated sensitivity of approximately 20-30% for detecting CTC at a prognostic level . The association between baseline characteristics and detection of CTC was analyzed. Overall survival was estimated by the Kaplan Meier method and compared using the Log Rank test. Results: The mean age of patients was 61 and 29 (64%) patients were male. CTC were detected in 13 (28%) patients. Patients with CTC tended to have larger tumor size, more tumor nodules, a higher CA19-9 level, increased CEA, lymph node involvement, and metastatic disease compared to patients without CTC. (Table) There was no significant association between CTC and demography (age, gender, and race) or underlying liver dysfunction . There was a trend towards poorer survival in patients with CTC compared to patients without CTC (p=0.09). Conclusion: CTC are detectable in patients with cholangiocarcinoma. The presence of CTC was associated with tumor burden and metastatic cancer. The prognostic implications of CTC in patients with CCA need further validation in a larger patient group.

619 ISOLATION AND ANALYSIS OF CIRCULATING TUMOR CELLS IN RENAL CELL CARCINOMA

You have accessJournal of UrologyKidney Cancer: Basic Research (IV)1 Apr 2013619 ISOLATION AND ANALYSIS OF CIRCULATING TUMOR CELLS IN RENAL CELL CARCINOMA E. Jason Abel, Ben P. Casavant, Jacob T. Tokar, Joshua M. Lang, and David J. Beebe E. Jason AbelE. Jason Abel Madison, WI More articles by this author , Ben P. CasavantBen P. Casavant Madison, WI More articles by this author , Jacob T. TokarJacob T. Tokar Madison, WI More articles by this author , Joshua M. LangJoshua M. Lang Madison, WI More articles by this author , and David J. BeebeDavid J. Beebe Madison, WI More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2013.02.170AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Circulating tumor cells (CTCs) have demonstrated prognostic ability in prostate and breast cancer but similar studies in Renal Cell Carcinoma (RCC) are limited because the current techniques rely on positive selection of cells using cell surface markers rarely expressed in RCC cells. We have designed a novel platform to permit the use of any antibody of interest bound to paramagnetic particles (PMPs) to isolate and purify PMP-bound cells via immiscible oil barriers. The purpose of this study was to demonstrate and validate RCC cell isolation from blood by positive selection of cells expressing carbonic anhydrase nine (CAIX). METHODS The Vertical Immiscible Filtration Assisted by Surface Tension (VerIFAST) platform was designed (BPC, DJB patent filed) using the relative dominance of surface tension in the microscale to create virtual walls between oil and aqueous phases filtering contaminants in a single step, while maintaining cell viability to permit further analysis. Initial experiments used samples of whole blood spiked with known RCC cell lines (786-0). After optimization of technique and confirmation of capture, samples from patients with locally advanced and metastatic RCC were evaluated after IRB approval and patient consent. Captured cells were stained with cytokeratins and Ki-67. RESULTS Initial experiments were designed to optimize CTC capture using anti-CAIX antibodies bound to PMP. A high capture efficiency of the spiked 786-0 cells (>75% capture efficiency) was able to be demonstrated using commercially available antibodies. Within the device, intracellular staining was demonstrated with successful staining of both cytokeratins and the proliferative marker, Ki-67(figure). Likewise, CTCs have been isolated from RCC patient samples using identical technique and staining for intracellular cytokeratins. CONCLUSIONS Isolation and purification of CTC cells from peripheral blood of RCC patients using CAIX is possible using this novel platform. We have demonstrated the ability to perform intracellular analyses, which will be important to study the prognostic value of CTC in RCC. Future studies will focus on nucleic acid isolation to investigate tumor heterogeneity and the role of CTC in cancer progression. © 2013 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 189Issue 4SApril 2013Page: e253 Advertisement Copyright & Permissions© 2013 by American Urological Association Education and Research, Inc.MetricsAuthor Information E. Jason Abel Madison, WI More articles by this author Ben P. Casavant Madison, WI More articles by this author Jacob T. Tokar Madison, WI More articles by this author Joshua M. Lang Madison, WI More articles by this author David J. Beebe Madison, WI More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Circulating stem cell–like epithelial cell adhesion molecule–positive tumor cells indicate poor prognosis of hepatocellular carcinoma after curative resection

Epithelial cell adhesion molecule-positive (EpCAM+) hepatocellular carcinoma (HCC) cells may constitute a tumor-initiating subpopulation in tumorigenic cell lines and HCC specimens. In the present study, EpCAM+ circulating tumor cells (CTCs) were identified prospectively in HCC patients undergoing curative resection, and the prognostic significance and their stem cell-like characteristics were investigated further. Blood samples from 123 HCC patients were tested prior to resection and 1 month thereafter. CTCs were present in 66.67% of patients, and the cell count measured in 7.5 mL of blood (CTC(7.5) ) ranged between 1 and 34. Fifty-one patients had CTC(7.5) of ≥2 preoperatively, and these patients developed tumor recurrence earlier than those with CTC(7.5) of <2 CTCs (P < 0.001). A preoperative CTC(7.5) of ≥2 was an independent prognostic factor for tumor recurrence (P < 0.001). Its prognostic significance also applied to patients with alpha-fetoprotein (AFP) levels of ≤400 ng/mL or subgroups with low recurrence risk (all P < 0.05). A significant decrease of CTC-positive rates (66.67% to 28.15%, P < 0.05) and CTC(7.5) values (2.60 ± 0.43 to 1.00 ± 0.36, P < 0.05) was observed 1 month after resection. Patients with consistent CTC(7.5) <2 had lower recurrence rates than those with values consistently ≥2 (15.5% versus 87.50%, P < 0.001). EpCAM+ CTCs displayed cancer stem cell biomarkers (CD133 and ABCG2), epithelial-mesenchymal transition, Wnt pathway activation, high tumorigenic potential, and low apoptotic propensity. Stem cell-like phenotypes are observed in EpCAM+ CTCs, and a preoperative CTC(7.5) of ≥2 is a novel predictor for tumor recurrence in HCC patients after surgery, especially in patient subgroups with AFP levels of ≤400 ng/mL or low tumor recurrence risk. EpCAM+ CTCs may serve as a real-time parameter for monitoring treatment response and a therapeutic target in HCC recurrence.

Detecting circulating tumor cells: current challenges and new trends.

Circulating tumor cells (CTCs) in the blood stream play a critical role in establishing metastases. The clinical value of CTCs as a biomarker for early cancer detection, diagnosis, prognosis, prediction, stratification, and pharmacodynamics have been widely explored in recent years. However, the clinical utility of current CTC tests is limited mainly due to methodological constraints. In this review, the pros and cons of the reported CTC assays are comprehensively discussed. In addition, the potential of tumor cell-derived materials as new targets for CTC detection, including circulating tumor microemboli, cell fragments, and circulating DNA, is evaluated. Finally, emerging approaches for CTC detection, including telomerase-based or aptamer-based assays and cell functional analysis, are also assessed. Expectantly, a thorough review of the current knowledge and technology of CTC detection will assist the scientific community in the development of more efficient CTC assay systems.

Effect of targeted therapy on circulating tumor cells in patients with metastatic breast cancer.

3 Background: Detection of ≥ 5 circulating tumor cells (CTCs) per 7.5 mL of blood before starting systemic treatment is a strong and independent predictor of worse progression-free survival (PFS) and overall survival (OS) in metastatic breast cancer (MBC) patients. It has been demonstrated that trastuzumab and bevacizumab can target CTCs in the peripheral blood of patients with breast cancer and modify the predictive value of the CTC count. We investigated time-related clinical trend of CTCs according to types of targeted therapy in MBC patients. Methods: Enumeration of CTCs was performed by the CellSearch technology as standard of care for 162 MBC patients receiving targeted therapy (trastuzumab, lapatinib, or bevacizumab) for MBC. The evaluation of CTCs was performed as follows: baseline CTC value defined as assay taken within 30 days before starting therapy, follow-up CTC value defined as the lowest CTC value after starting therapy. We analyzed the effect of treatments on CTC count by Wilcoxon matched pair test and estimated PFS and OS by Kaplan-Meier curves. Results: After a median follow-up of 26 months, 143 of 162 (88%) showed progression of disease and 96 (59%) had expired. Sixty-two (38%) patients have received treatment with trastuzumab, 31 (19%) patients with lapatinib, and 69 (43%) patients with bevacizumab. Among patients receiving anti-HER2 targeted treatments, trastuzumab and lapatinib, and those receiving bevacizumab, no differences in terms of median PFS and OS were observed between patients with CTCs greater or equal than 5 and less than 5. Analyzing separate anti-HER2 targeted treatments, we found trastuzumab decreased the number of CTCs at follow-up (P = 0.0003), whereas lapatinib did not (P = 0.14). However, bevacizumab also decreased the number of CTCs at follow-up (P &lt; 0.0001). Conclusions: In MBC patients treated with targeted therapies, basal CTC count was not predictive of PFS and OS. Trastuzumab and bevacizumab significantly decreased the number of CTCs after starting treatment. Moreover, measuring CTCs during the follow-up of MBC patients may represent a predictive tool for targeted therapy failure.

Meta-Analysis of the Prognostic Value of Circulating Tumor Cells in Breast Cancer

The prognostic value of circulating tumor cells (CTC) detected in breast cancer patients is currently under debate. Different time points of blood collections and various CTC assays have been used in the past decades. Here, we conducted the first comprehensive meta-analysis of published literature on the prognostic relevance of CTC, including patients with early and advanced disease. A comprehensive search for articles published between January 1990 and January 2012 was conducted; reviews of each study were conducted and data were extracted. The main outcomes analyzed were overall survival (OS) and disease-free survival (DFS) in early-stage breast cancer patients, as well as progression-free survival (PFS) and OS in metastatic breast cancer patients. Pooled hazard ratio (HR) and 95% confidence intervals (CIs) were calculated using the random and the fixed-effects models. Subgroup and sensitivity analyses were also conducted. Forty-nine eligible studies enrolling 6,825 patients were identified. The presence of CTC was significantly associated with shorter survival in the total population. The prognostic value of CTC was significant in both early (DFS: HR, 2.86; 95% CI, 2.19-3.75; OS: HR, 2.78; 95% CI, 2.22-3.48) and metastatic breast cancer (PFS: HR, 1.78; 95% CI, 1.52-2.09; OS: HR, 2.33; 95% CI, 2.09-2.60). Further subgroup analyses showed that our results were stable irrespective of the CTC detection method and time point of blood withdrawal. Our present meta-analysis indicates that the detection of CTC is a stable prognosticator in patients with early-stage and metastatic breast cancer. Further studies are required to explore the clinical utility of CTC in breast cancer.

767 - The Diagnosis of Malignant Pancreatic Tumours by Circulating Tumour Cell Detection

ABSTRACT Introduction The fine needle aspiration by endoscopic ultrasound guide (EUS FNA) is a diagnostic examination of choice in solid tumour of the pancreas. This invasive technique has a sensitivity of about 70%. The search for circulating tumour cells (CTC) is a non invasive procedure, which could represent an alternative or complement to EUS FNA diagnostic. The objective of this prospective pilot study was to evaluate the diagnostic value of research CTC versus EUS FNA for the diagnosis of a solid tumour of the pancreas (STP). Patients and methods From 01/01 to 30/09/2011, all patients undergoing an EUS FNA for a STP were included. EUS FNA was performed with a 22 gauge needle and analyzed by two experienced pathologists. For detection of CTC, 10 ml of blood collected in the periphery before FNA was filtered by technology ScreencellCyto â, stained with Giemsa and analyzed by a cytologist. Peripheral cells were considered tumour if they had the following morphology: kernel> 7 m, anisocytosis, membrane irregularities, presence of a large nucleolus. Results Twenty six patients with TSP were included (14 men and 12 women), mean age was 64.2 years. The tumor was potentially resectable in 11 cases, 8 cases had a locoregional recurrence and 7 a metastatic extension. In total, 23/26 cases were analyzed due to technical failure of the CTC research (insufficient material) and two technical failures of EUS FNA. 20 patients had cancer objectified (including 15 adenocarcinomas or 57%) by EUS FNA pancreatic histological analysis of the specimen and/or clinical course. In this population of 26 patients the sensitivity of the search CTC was 60%, specificity 100%, positive predictive value 100% and negative predictive value of 27%. On the results of FNA sensitivity for the diagnosis of cancer was 75%, specificity 100%, PPV of 100% and NPV of 37.5%. In patients whose FNA was contributory to the sensitivity of CTC research was 83%, specificity 54%, PPV of 66% and NPV of 75%. Conclusion The detection of CTC for the diagnosis of adenocarcinoma in case of tumours of the pancreas is a technique feasible, non-invasive, with a satisfactory diagnostic yield. The results of this pilot study, the continued progress in the analysis of CTC and a confirmation of this results in a higher independent population could allow us to propose this procedure in a first diagnostic step. Disclosure All authors have declared no conflicts of interest.

Prognostic significance of circulating tumor cell (CTC) levels at various times during first- and second-line chemotherapy for metastatic breast cancer (MBC).

e21077 Background: CTCs have prognostic capability in the treatment of MBC based on a dichotomous level of ≥5/7.5 ml blood (Hi) vs. &lt;5/7.5 ml blood (Lo) at baseline and first follow-up. The value of CTCs beyond baseline is not well established, and the implication of values that are reduced but remain high has not been explored. Methods: Chart review of patients (pts) on 1st or 2nd line treatment of MBC, with CTC determinations between 2/2008 and 9/2011, were retrospectively identified at a large community oncology practice. Pts with ≥2 CTCs or 1 CTC ≥5 were eligible. Demographics, treatment regimens and progression-free survival (PFS) were assessed. The Veridex Cell Search system was utilized for all CTC determinations. Qualifying baseline CTCs were those drawn -14 days to +30 days from start of treatment. Results: 221 eligible pts were identified, 71 with baseline CTCs in 1st line, and 84 in 2nd line. Median age was 59.5 (range 26-90), 40.7% were African-American, 17.6% HER2+, and 63%/49% ER/PR+. The median time to baseline CTC was 5 days in the 1st line and 1 day in the 2nd line. 1st line PFS was 8.0 vs. 5.8 mo among baseline Hi vs. Lo groups (p = 0.085). 2nd line PFS was 3.7 vs. 4.0 mo for Hi and Lo groups, respectively, (ns). Follow-up CTCs were obtained at clinical convenience. A 90 day landmark was used for analysis of PFS by four baseline/follow-up CTC pattern groups. 1st line PFS showed medians ranging from 6.0 mo (Hi/Hi) to 10.2 mo (Lo/Lo). In 1st line pts with Hi baseline CTCs (n=24), median PFS was 6.0 vs. 7.0 mo for Hi vs. Lo at follow-up (p = .64). Grouping pts with Hi baseline CTCs by reductions in absolute CTC count at follow-up (&lt;33% vs. ≥33%) showed median PFS 3.5 mo for &lt;33% reduction, 8.8 mo for ≥33% reduction (p = .0179). Sensitivity analyses with other cutoffs in reduction from 20-80% showed similar results. Conclusions: In the community setting, baseline and subsequent CTCs obtained at various times after baseline yield clinically useful prognostic information. Pts with positive baseline CTC levels experiencing a reduction of ≥33% exhibit significantly longer PFS, indicating that a simple high/low approach to the test can be modified to yield more prognostic value.

Results of telomerase activity measurements from live circulating tumor cells captured on a slot microfilter in a phase III SWOG-coordinated prostate cancer trial (S0421).

4663 Background: Analysis of circulating tumor cells (CTC) is a promising biomarker strategy in advanced prostate cancer, and telomerase activity (TA) is a recognized cancer marker. To test whether CTC TA is prognostic for survival (OS), we developed a novel Parylene-C slot microfilter capable of capturing live CTC and used it to measure CTC TA as part of a Phase III SWOG-coordinated therapeutic trial in metastatic castration resistant prostate cancer (S0421). Methods: Blood samples were drawn into EDTA tubes and shipped overnight to a central processing site. After Ficoll centrifugation, low constant pressure was used to pass the mononuclear cell layer through two slot microfilters in series as published previously (filter1 captures CTC + background white blood cells; filter2 captures only background white blood cells). Filter-trapped cells were lysed in CHAPS buffer and assayed for TA using qPCR-based telomeric repeat amplification. In parallel, CTC were enumerated using CellSearch (J&amp;J). Cox regression was used to evaluate the association between baseline (pre-treatment) TA and OS overall, and within subgroups characterized by good prognosis (&lt;5) vs. poor prognosis (&gt;=5) baseline CTC counts. CART regression was used to explore potential prognostic subgroups based on baseline PSA, CTC, and TA cutpoints. Results: Samples were obtained from 263 patients. While no association was observed between TA and OS overall, in patients with baseline CTC &gt;=5 (108 of 263 or 41% of patients), TAfilter2 – TAfilter1 representing high CTC TA relative to background blood cells was associated with a hazard ratio (HR) of 1.14 (95% CI 1.05-1.23, p&lt;0.001) for OS after adjusting for risk factors and remained significant when also adjusting for CTC: HR 1.14 (95% CI 1.04-1.23; p=0.005). Exploratory CART regression assessing baseline PSA, CTC, and TA identified risk groups based only on CTC and TA values. Conclusions: Baseline TA from CTC live-captured on a new slot microfilter is the first CTC biomarker shown to be prognostic of OS in men with CTC counts &gt;=5 in a prospective clinical trial. CTC TA may be useful for further identifying prognostic groups in this population.

Circulating tumor cells (CTCs) in patients (pts) with small cell lung cancer (SCLC) as a marker of disease burden and therapeutic response, and predictor of disease relapse.

7092 Background: Currently there are no validated biomarkers for assessment or prediction of disease burden or activity in SCLC. Enumeration of CTCs by CellSearch is FDA approved, highly reproducible and validated in other malignancies. Application as a prognostic and predictive marker in SCLC is limited due to a lack of studies documenting serial monitoring in pts on therapy. Methods: We are conducting a prospective study serially enumerating CTCs in pts with newly diagnosed SCLC. CTC number (per 7.5 ml peripheral blood) and percentage of CTCs demonstrating DNA damage and apoptosis based on γH2AX and M30 staining respectively, are being assessed prior to initiation of chemotherapy, during each cycle and at relapse. We are correlating CTC number with disease stage, number of metastatic sites, response to therapy, and time to progression (TTP). Results: 21 SCLC pts are evaluable. 9 pts with limited disease (LD) had median baseline CTC value of 1 (0-8); only 2 of 9 pts had &gt;5 CTCs. 12 pts with extensive disease (ED) had median baseline CTC value of 80.5 (0-37780); 8 of 12 pts had &gt;5 detectable CTCs (p value 0.02). Amongst the 12 pts with ED, median baseline CTC count was higher in pts with ≥3 (n=3) compared to 1-2 sites of metastatic disease (n=9) (2668 vs 71; p value 0.52). Median percentage of CTCs positive for γH2AX and M30 was also higher for pts with ≥3 compared to 1-2 metastatic sites (83, 164.5 vs. 2, 7.5) (p-value 0.40, 0.69). Serial CTC data are available on 3 pts with ED; all had responsive disease and reduction in CTC number to 0-1 after 2 cycles of chemotherapy. As this protocol is ongoing, correlation of CTCs with updated response status and TTP will be presented at the ASCO meeting. Conclusions: CTCs can be isolated and serially enumerated in pts with SCLC. Baseline CTCs correlate directly with disease stage. In pts with ≥ 3 metastatic sites, baseline CTCs tend to be greater and show higher levels of DNA damage and apoptosis compared to those with 1-2 metastatic sites. Reduction in CTCs is associated with radiographic response to therapy. Correlation between absolute number at baseline and TTP is not yet known.

Circulating tumor cells in immunohistochemical subtypes of metastatic breast cancer: lack of prediction in HER2-positive disease treated with targeted therapy

Circulating tumor cells (CTCs) are associated with inferior prognosis in metastatic breast cancer (MBC). We hypothesized that the relationship between CTCs and disease subtype would provide a better understanding of the clinical and biologic behavior of MBC. We retrospectively analyzed 517 MBC patients treated at a single institution. Subtypes of primary tumors were analyzed by immunohistochemical (IHC) or fluorescent in situ hybridization analyses and CTCs were enumerated by CellSearch(®) at starting a new therapy. Overall survival (OS) and progression-free survival durations for each IHC subtype were determined. At a median follow-up of 24.6 months, 276 of 517 (53%) patients had died. The median OS for patients with <5 and ≥ 5 CTCs were 32.4 and 18.3 months, respectively (P < 0.001). Except in HER2+ patients, the prognostic value of CTCs was independent of disease subtype and disease site. In this large retrospective study, CTCs were strongly predictive of survival in all MBC subtypes except HER2+ patients who had been treated with targeted therapy. Our results clearly demonstrate the value of enumerating CTCs in MBC and strongly suggest an interesting biological implication in the HER2+ subset of patients that need to be further explored.

High independent prognostic and predictive value of circulating tumor cells compared with serum tumor markers in a large prospective trial in first-line chemotherapy for metastatic breast cancer patients

Circulating tumor cells (CTCs) are a prognostic marker in metastatic breast cancer, but comparisons with serum tumor markers (CA 15-3, carcinoembryonic antigen and lactate dehydrogenase) variations are needed. CTCs were counted with CellSearch® at baseline, before cycle 2 (C2) and cycle 3 or 4 (C3/4) in 267 metastatic breast cancer patients on first-line chemotherapy with/without targeted therapy. Baseline CTC detection rate was 65% with ≥1 CTC/7.5 ml threshold and 44% with ≥5 CTC/7.5 ml and was independent of subtypes (luminal, triple negative, human epithelial growth factor receptor 2 (HER2)+). CTCs were associated with tumor markers, bone/liver involvement, tumor burden and performance status. CTC detection ≥1 CTC/7.5 ml was a strong prognostic factor for progression-free survival (PFS), P < 0.0001. Threshold of CTC ≥5 was statistically significant for PFS and overall survival (OS), P = 0.03 on multivariate analysis. Among patients with ≥5 CTC/7.5 ml at baseline, 50% had <5 CTC/7.5 ml at C2. Changes were correlated with both PFS and OS (P < 0.0001). All patients receiving anti-HER2 therapy had <5 CTC/7.5 ml after three cycles of treatment. This is the largest prospective series validating the prognostic value of CTC independently from serum tumor marker. Elevated CTCs before C2 are an early predictive marker of poor PFS and OS, which could be used to monitor treatment benefit. CTC decrease under treatment seems stronger with targeted therapy.

Circulating tumour cells in prostate cancer patients receiving salvage radiotherapy

Within 10 years of radical prostatectomy (RP), up to 30% of prostate cancer (PCa) patients will have a rise in prostate-specific antigen (PSA), requiring radiation therapy (RT). However, with current technology, distinction between local and distant recurrent PCa is not possible. This lack of an accurate test constrains the decision whether to offer systemic or local treatment. We hypothesise tests for detecting circulating tumour cells (CTCs) within the blood may assist with clinical decision-making and in this pilot study we investigated whether CTCs could be detected in this patient population using the CellSearch® system. Blood samples were collected from PCa patients (n=26) prior to RT and 3 months following completion of RT. Samples were analysed for PSA level via immunoassay and CTC number using the CellSearch® system. CTCs could be detected in this patient population and following RT CTCs appeared to decrease. However, no association was observed between a higher PSA and an increased number of CTCs pre- or post-RT. Interestingly, patients who failed RT trended toward an increased/ unchanged number of CTCs following RT vs. a decreased number in patients with RT response. Our results demonstrate that CTCs can be detected in early-stage PCa and suggest the possibility that post-treatment reduction in CTC levels may be indicative of RT response . We are currently evaluating CTCs in a larger cohort of patients to validate our preliminary findings and further investigate the prognostic value of CTCs in this patient population.

Prognostic relevance of circulating CK19 mRNA in advanced malignant biliary tract diseases

To determine the role of circulating tumor cells (CTCs) in prediction of the overall survival of patients with advanced malignant biliary tract obstruction. We investigated the prognostic value of CTCs by examining two markers, cytokeratin (CK) 19 and human telomerase reverse transcriptase (hTERT) mRNA, in 40 patients diagnosed with advanced malignant biliary tract diseases. Quantitative real-time reverse transcription polymerase chain reaction was used to detect CK19 and hTERT mRNA in the peripheral blood of these patients. Overall survival was analyzed using the Kaplan-Meier method and Cox regression modeling. Positive CK19 and hTERT mRNA expression was detected in 45% and 60%, respectively, of the 40 patients. Univariable analysis indicated that positive CK19 mRNA expression was significantly associated with worse overall survival (P = 0.009). Multivariable analysis determined that positive CK19 mRNA expression, patient's age and serum bilirubin were each independently associated with overall survival. CK19 mRNA expression levels in peripheral blood appear to provide a valuable marker to predict the overall survival of patients with advanced malignant biliary tract obstruction.

P4-07-10: Circulating Tumor Cells in Newly Diagnosed Inflammatory Breast Cancer.

Abstract Background: Inflammatory breast cancer (IBC) is one of the most aggressive forms of breast cancer and is associated with special clinical and biological features. Circulating tumor cells (CTC) are an independent prognostic factor in metastatic breast cancer for progression-free and overall survival. Previously we showed that metastatic IBC patients treated with first and subsequent lines of chemotherapy had a lower number of CTC when compared with CTC levels of non-IBC patients; hence the prognostic value of CTC in mIBC patients is limited. In the present study, we investigated the prognostic value of baseline CTC in newly diagnosed IBC patients. Patients and methods: This retrospective study included 84 newly diagnosed IBC (37 stage III B or C and 47 stage IV) patients treated with neoadjuvant therapy or first line chemotherapy between January 2004 and July 2009 at the MD Anderson Cancer Center. The median age was 55 years (range, 23–78). Twenty-four (28.8%) patients were HER2 positive, 36 (42.9%) hormone receptor positive and 33 (39.3%) were triple receptor negative. CTC were detected and enumerated using the CellSearch® system before patients started chemotherapy. Progression free survival (PFS) and overall survival (OS) were calculated from the date of CTC measurement and estimated by the Kaplan-Meier product limit method. Results: At baseline, 64 (76.2%) patients had at least ≥1 CTC and 29 (34.5%) ≥5 CTC. Proportions of patients with stage III IBC with ≥1 CTC and ≥5 CTC were lower than those of newly diagnosed stage IV IBC patients (67.6% vs. 86%; p = 0.12 and 24.3% vs. 42.6%; p = 0.11, respectively). At a median follow up of 22.4 months (range: 4.8 - 58.3 months), 48 (57.1%) patients experienced disease progression and 26 (31.0%) had died. Patients with &amp;lt; 5 CTC had similar PFS (p = 0.36) and OS (p = 0.80) to those of patients with ≥5 CTC, respectively. We investigated the prognostic value of CTC ≥ 1 in stage III IBC patients, as well. There was no difference in PFS (p = 0.71) and OS (p = 0.15) in patients with CTC = 0 vs. those of patients with CTC ≥ 1, respectively. Moreover, we correlated CTC levels with prognosis, using different CTC threshold, but we observed no correlation between baseline CTC and patients’ outcome (Table 1). Conclusions: CTC can be detected in a large proportion of patients with newly diagnosed IBC; however, baseline CTC was not prognostic for PFS and OS. Collective dissemination of cancer cells via lymphovascular tumor emboli and/or epithelial-mesenchymal transition accompanied by inadequate detection of CTC due to lack of sensitivity of current assays may account for limited prognostic value of CTC in newly diagnosed IBC. Nevertheless, sample size and study power could influence study results as well. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-10.

Determination of cut-offs for circulating tumor cell measurement in metastatic cancer

Evaluation of: Pierga JY, Hajage D, Bachelot T et al. High independent prognostic and predictive value of circulating tumor cells compared with serum tumor markers in a large prospective trial in first-line chemotherapy for metastatic breast cancer patients. Ann. Oncol. DOI: 10.1093/annonc/mdr263 (2011) (Epub ahead of print).The metastatic transformation of epithelial tumors progresses through various steps leading to the generation of circulating tumor cells (CTCs). Measurement of CTCs in the peripheral blood is being increasingly recognized as a promising tool in breast oncology. Several studies have evaluated the prognostic significance of CTCs in newly diagnosed metastatic breast cancer (MBC) patients. The IC 2006-04 was a high-powered, prospective, multicenter, observational study conceived to assess CTC changes in women with MBC treated with first-line chemotherapy. Levels ≥5 CTCs/7.5 ml blood at baseline and before the second cycle of treatment were independent prognostic factors associated with shorter progression-free and overall survival. This study provides further level II evidence for the clinical and prognostic value of CTCs in MBC, confirming data from earlier small studies. It also provides proof that CTCs should be investigated in ongoing interventional trials to see if better patient outcomes can be attained by altering treatment based on CTC levels.

Circulating tumor cells count and characterization in a male breast cancer patient

A 64-y-old man presented to Medical Oncology Department a metastatic invasive ductal breast carcinoma, positive for estrogen (ER) and progesterone receptors (PR) and Her2/neu negative. The patient was treated with different lines of therapy, with rapid radiological progression of disease. After four courses of a third-line chemotherapy, a radiological stable disease was maintained. The patient was followed by serial blood drawings for the characterization and count of circulating tumor cells (CTC). This is the first report concerning the predictive and prognostic value of CTC in a male breast cancer patient.

Circulating Tumor Cells as a Predictive Biomarker in Patients With Hormone-sensitive Prostate Cancer

Introduction Circulating tumor cell (CTC) enumeration by using the Cellsearch platform has established prognostic and predictive value in patients with metastatic castration-resistant prostate cancer (mCRPC). Limited information exists regarding the clinical utility of CTC enumeration in metastatic hormone-sensitive prostate cancer (mHSPC). The goal of this study was to prospectively determine the relative clinical utility of CTCs in mHSPC. Patients and Methods We analyzed serial CTC in conjunction with other classic biomarkers in 33 consecutive patients treated at the Nevada Cancer Institute with HSPC initiating androgen deprivation therapy and correlated these patients with prognostic prostate-specific antigen (PSA) endpoints and onset of CRPC. Results Initial CTC correlated positively with lactate dehydrogenase and alkaline phosphatase, and were unrelated to PSA and testosterone. In univariate analysis, baseline CTC, alkaline phosphatase, lactate dehydrogenase, testosterone, and follow-up CTC were individual predictors of progression to CRPC. In a multivariate Cox regression, only baseline CTC retained independent predictive value. Threshold analysis revealed the cutpoint that optimized specificity and sensitivity of the test to be 3 cells per 7.5 mL whole blood. Baseline CTC also correlated well with PSA nadir benchmarks. Conclusions Initial CTC values predict the duration and magnitude of response to hormonal therapy. CTC enumeration may identify patients at risk of progression to CRPC before initiation of androgen deprivation therapy.