Prognostic Value Of Circulating Tumor Cells Research Articles

Exploring the diagnostic and prognostic significance of circulating tumor cells in stage II-IV colorectal cancer using a nano-based detection method.

Colorectal cancer (CRC) is a leading cause of cancer mortality globally, underscoring the urgency for a noninvasive and effective biomarker to enhance patient prognosis. Circulating tumor cells (CTCs), a potential marker for real-time tumor monitoring, are limited in clinical utility due to the low sensitivity of existing detection methods. Previously, we introduced a novel nano-based CTCs detection method that relies on the electrical properties of cell surfaces, thus eliminating the need for specific molecular biomarkers. In this study, we used this technique to evaluate the diagnostic and prognostic value of CTCs in stage II-IV CRC. A total of 194 participants were included, consisting of 136 CRC patients and 58 healthy individuals. The peripheral blood of the participants was collected, and CTC enumeration was performed utilizing the nano-based detection method that we newly developed. The receiver operating characteristic (ROC) curve and multivariate Cox proportional-hazards analysis were used to assess the effectiveness of CTCs for diagnosing CRC and predicting patient prognosis. The nano-based method demonstrated an ability to differentiate CRC patients from healthy individuals with a sensitivity of 84.6% and a specificity of 94.8%. Furthermore, baseline CTC levels were predictive of progression-free survival (PFS) in CRC patients, with lower levels associated with longer PFS compared to higher levels (4.5 vs 8.0 months at 15 CTCs/mL, p = 0.016; 4.4 vs 8.0 months at 20 CTCs/mL, p = 0.028). We also explored the dynamic changes in the number of CTCs after 1 to 5 cycles of chemotherapy. Patients with increasing CTC levels typically experienced disease progression (PD), while those with decreasing levels often achieved a partial response (PR) or maintained stable disease (SD). These findings suggest that the dynamic fluctuations in CTC counts are closely tied to the clinical course of the disease. Our study indicates the potential of nano-based CTCs detection in diagnosing and predicting outcomes for patients with stage II-IV CRC.

Abstract 7500: Distribution and prognostic significance of circulating tumor cells (CTCs) and tumor-derived extracellular vesicles (tdEVs) in patients (pts) with lobular metastatic breast cancer (MBC)

Abstract Background: Invasive lobular carcinoma (ILC) has distinctive clinical and molecular features compared with invasive ductal carcinoma (IDC). CTCs and tdEVs are independent prognostic factors in MBC, however, liquid biopsy studies focusing on ILC are to date scarce. Higher CTC levels have been observed in ILC than IDC. One study including 28 ILC pts suggested the use of higher CTC cutoff for prognosis stratification. The clinical significance of tdEVs in ILC is unexplored. This study aimed to assess differences in the distribution and prognostic value of CTCs and tdEVs between ILC and IDC. Methods: Blood samples were collected from 304 pts with MBC before starting a new line of therapy at Northwestern University (Chicago, IL) between 2016 and 2021 (NU16B06 trial). Blood was processed with the CellSearch® system. The ACCEPT software was applied to CellSearch® images to automatically enumerate CTCs and tdEVs. Association of CTCs and tdEVs with overall survival (OS) was tested in ILC and IDC pts. A count of CTCs ≥ 5 was considered high. The cutoff levels for tdEVs were < 20 (low), 20-79 (intermediate), and ≥ 80 (high), as previously reported. Additional exploratory cutoffs for CTCs (≥ 20, ≥ 50, ≥ 80, and ≥ 100) and tdEVs (based on quartiles of tdEV distribution in the overall population and ILC) were also evaluated. Results: Of the 304 pts, 47 had ILC while 257 had IDC. 56% of pts received first-line therapy. Median CTC count was 8 [interquartile range (IQR) 2-35] in ILC and 1 (IQR 0-8) in IDC pts (P <.001). A significantly higher median tdEVs count was observed in ILC (36; IQR 18-115) than in IDC (11; IQR 2-86) pts (P =.002). High levels of CTCs (≥5) were not associated with OS in ILC (P =.88), even when higher cutoffs (≥ 20, ≥ 50, and ≥ 80) were used. Only the detection of ≥ 100 CTCs was significantly associated with OS in ILC pts (median OS 36 vs 10 months; HR 3.4; P =.028). In contrast, the prognostic effect of CTCs ≥ 5 was strong in IDC and maintained for all cutoffs. Similarly, while the prognostic value for tdEVs was confirmed for IDC using both 20-80 and exploratory cutoffs (3-105 and 18-155), no association between tdEV levels and OS was observed in ILC regardless of the cutoffs used. Conclusion: ILC is associated with higher CTCs and tdEVs compared to IDC, probably due to the impaired cell-cell adhesion that characterizes ILC. Unlike IDC, the prognostic effect for the established cutoff of ≥ 5 CTC was not observed in ILC. A higher CTC cutoff could be considered for this subtype of BC. For tdEV no association with OS was observed, regardless of the cutoff used. These findings emphasize that ILC is a distinct entity also in the liquid biopsy features. Because of the low prevalence of ILC, research efforts should be directed at combining data from ILC pts to better characterize this subtype of BC and understand the reason behind the different associations with OS as compared to IDC. Citation Format: Eleonora Nicolo, Lorenzo Gerratana, Lorenzo Foffano, Laura Munoz-Arcos, Mara S. Serafini, Maroua Manai, Letizia Pontolillo, Nadia Bayou, Elisabetta Molteni, Amanda K. Strickland, Caterina Gianni, Youbin Zhang, Paolo D'Amico, Andrew A. Davis, Jeannine Donahue, Huiping Liu, William J. Gradishar, Ami N. Shah, Giuseppe Curigliano, Carolina Reduzzi, Massimo Cristofanilli. Distribution and prognostic significance of circulating tumor cells (CTCs) and tumor-derived extracellular vesicles (tdEVs) in patients (pts) with lobular metastatic breast cancer (MBC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7500.

Prognostic Significance of Excision Repair Cross-Complementation Group 1 on Circulating Tumor Cells for Nasopharyngeal Carcinoma.

Liquid biopsy, including the detection of circulating tumor cells (CTCs), has emerged as a promising tool for cancer diagnosis and monitoring. However, the prognostic value of CTCs in nasopharyngeal carcinoma (NPC) remains unclear due to the lack of phenotypic characterization. The expression of Excision Repair Cross-Complementation Group 1 (ERCC1) and CTCs epithelial-mesenchymal transition (EMT) have been associated with treatment efficacy. In this study, we aimed to evaluate the prognostic significance of ERCC1 expression on CTCs and their EMT subtypes before treatment in NPC. We retrospectively analyzed 108 newly diagnosed locally advanced NPC patients who underwent CanPatrol™ CTC testing between November 2018 and November 2021. CTCs were counted and classified into epithelial, epithelial-mesenchymal hybrid, and mesenchymal subtypes. ERCC1 expression was divided into negative and positive groups. Clinical features and survival outcomes were analyzed. The positive rate of CTCs was 92.6% (100/108), with an ERCC1 positivity rate of 74% (74/100). Further analysis of the subtypes showed that positive ERCC1 on mesenchymal CTCs was associated with a later N stage (P = .01). Positive ERCC1 expression was associated with poor overall survival (OS; P = .039) and disease-free survival (DFS; P = .035). Further analysis of subtypes showed that the positive ERCC1 on mesenchymal-type CTCs was associated with poor OS (P = .012) and metastasis-free survival (MFS; P = .001). Our findings suggest that ERCC1 expression on CTCs may serve as a new prognostic marker for NPC patients. Evaluating CTCs subtypes may become an auxiliary tool for personalized and precise treatment.

Current Status of Circulating Tumor Cells in Head and Neck Squamous Cell Carcinoma: A Review.

Circulating tumor cells (CTCs) are found in the blood of patients with cancer, including head and neck squamous cell carcinomas (HNSCCs). The aim is to review the most up-to-date status of CTCs for applications in patients with HNSCC. English articles in PubMed. All the studies on CTCs in HNSCCs in the literature were reviewed. There is emerging information on the diagnostic and prognostic value of CTCs in HNSCCs. Evidence also highlights the advantages of various downstream analysis approaches over circulating tumor DNA (ctDNA), such as single-CTC analysis, ex vivo, and in vivo expansion of CTCs. Multiple phenotypic surface markers (cytokeratins, EpCAM, vimentin, etc.), used for CTCs characterization using different immunoassays, could predict disease progression as well as patients' response to treatment efficacy. Immune checkpoint inhibitors' status in CTCs could also provide better insight into treatment. Clonal expansion of CTCs and single-cell analysis of CTCs are the most emerging fields nowadays which may offer an understanding of the mechanism of tumor evolution as well as therapeutic efficacy. Although several clinical trials are ongoing, limitations still exist in the detection and characterization of CTCs. Due to the lack of a gold standard protocol, the sensitivity and specificity of CTC enumeration methods vary. Prospective clinical trials are still needed before CTCs can be employed as diagnostic and prognostic markers in the clinical management of patients with HNSCC.

Circulating tumor cells in breast cancer: clinical and molecular parallels

Background. Breast cancer (BC) is the most common type of malignant neoplasm among women, with a high rate of metastasis. Early non-invasive diagnosis is required to increase the effectiveness of anticancer therapy.Objective: to determine the content of circulating tumor cells (CTCs) and their derivatives in the peripheral blood using the MDA-231 aptamer, compare the results obtained with the clinical and molecular characteristics of BC.Materials and methods. The study included 22 patients with BC. Detection of CTCs and circulating tumor microemboli was carried out in 3.5 ml of the blood of BC patients with the help of the MDA-231 aptamer which is affine for breast cancer cells, labeled with the fluorescent Cy3 dye. The count of CTCs in the blood samples was performed using fluorescent and laser scanning microscopy.Results and conclusions. The content of CTCs and circulating tumor microemboli in the peripheral blood of patients with BC of various molecular subtypes was analyzed using the MDA-231 aptamer. The relationship between the number of CTCs and the molecular biological subtype was revealed. The obtained results show the possible prognostic value of CTCs use for monitoring effectiveness of anticancer therapy and control of recurrence of BC.

Circulating tumour cells at baseline and late phase of treatment provide prognostic value in breast cancer

To determine the prognostic value of the timing of circulating breast tumour cell measurement during treatment, peripheral blood from 164 patients with breast disease was collected. Circulating tumour cells (CTCs) were enriched by using immunomagnetic nanospheres (IMNs) and were identified by using immunofluorescent staining. The CTC shows nuclear-positive, EpCAM-positive, CK19-positive, and CD45-negative. Patients with CTC positivity (> 19/7.5 mL blood) had shorter progression-free survival (PFS) and overall survival (OS) than those with negative results (≤ 19/7.5 mL blood) at baseline. Surgery caused an increase in the number and prevalence of CTCs, and the effect disappeared on day 14 after surgery. During adjuvant chemotherapy, CTCs detected before therapy was only correlated with PFS; however, CTCs at the end of adjuvant chemotherapy were correlated with both PFS and OS. The PFS and OS of the CTC-positive group were significantly shorter than those of the CTC-negative group at the end-point follow-up visit. The prognostic value of CTCs at different measurement time points was demonstrated during breast cancer treatment. Surgery and chemotherapy affected the prevalence of CTCs, leading to different prognostic relevance of CTCs at different treatment stages. CTCs detected at baseline or in the late phase of treatment are preferable for prognosis.

Assessment of the Clinical Utility of Circulating Tumor Cells at Different Time Points in Predicting Prognosis of Patients With Small Cell Lung Cancer: A Meta-Analysis.

ObjectivesNumerous studies have elucidated that circulating tumor cells (CTCs) have significant prognostic value in various solid tumors. However, the prognostic value of CTCs in small cell lung cancer (SCLC) remains controversial. The current study was performed to investigate the prognostic significance of different time points of CTCs in SCLC.MethodsPubMed, EMBASE, Web of Science, and Cochrane Library databases were retrieved for eligible studies. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated to investigate the association between CTCs level and overall survival (OS) and progression-free survival (PFS) in SCLC. Furthermore, subgroup analyses, sensitivity analysis, Begg’s and Egger’s tests were also conducted.ResultsSixteen cohort studies with 1103 participants were eligible for this meta-analysis. Our results revealed that higher pretreatment CTCs level was significantly correlated with worse OS in SCLC no matter CellSearch (HR, 2.95; 95%CI, 1.56-5.58; P = .001) or other methods (HR, 2.37; 95%CI, 1.13-4.99; P = .023) was used to detect CTCs. Higher pretreatment CTCs status detected by CellSearch was associated with shorter PFS (HR, 3.75; 95%CI, 2.52-5.57; P < .001), while there was no significant association when other methods were adopted to CTC detection (HR, 2.04; 95%CI, .73-5.68; P = .172). Likewise, we observed that higher post-therapy CTCs level detected by both CellSearch (HR, 2.99; 95%CI, 1.51-5.93; P = .002) and other methods (HR, 4.79; 95%CI, 2.03-11.32; P < .001) was significantly correlated with decreased OS in SCLC. However, higher post-therapy CTCs count detected by CellSearch was not correlated with worse PFS (HR, 1.80; 95%CI, .83-3.90; P = .135). Sensitivity analysis demonstrated that the pooled data were still stable after eliminating studies one by one. However, significant publication bias was observed between pretreatment CTCs level detected by CellSearch and OS of SCLC.ConclusionDynamic monitoring of CTCs level could be a non-invasive and effective tool to predict the disease progression and prognosis in patients with SCLC.

Prognostic and predictive effects of circulating and disseminated tumor cells in breast cancer: A National Cancer Database (NCDB) analysis.

1029 Background: Alongside other biomarkers, circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) could contribute to our growing understanding of the breast cancer (BC) “liquid biopsy”. This study evaluated 1) clinicopathologic factors associated with CTCs and DTCs, 2) the prognostic value of CTCs and DTCs by disease stage, 3), the efficacy of chemotherapy by CTC and DTC status. Methods: We conducted a retrospective analysis of BC using the 2004-2016 National Cancer Database (NCDB). The NCDB defines CTCs as isolated tumor cells (ITCs) found in the blood (using assays such as reverse transcriptase polymerase chain reaction or immunohistochemistry) distant from the breast. DTCs are ITCs found in the bone marrow or other non-regional tissues. To evaluate variables associated with CTCs or DTCs, we used chi-squared and Wilcoxon rank-sum tests (univariate), followed by multivariate logistic regression. Consequently, we included CTC or DTC status in a multivariate, stage-by-stage Cox regression analysis for overall survival (OS). After adjusting for receptor status and staging, we used the Kaplan-Meier method to explore chemotherapy efficacy in CTC- or DTC-positive vs. CTC- or DTC-negative subsets. Results: 4,846 cases reported CTC-status, 1,454 (21.1%) of which were positive. 4,993 cases reported DTC-status, 1,400 (20.3%) of which were positive. Factors associated with positive CTC status were HER2-positivity, progesterone receptor-positivity, lobular histology and N-staging. Factors associated with positive DTC status were being White, HER2-positivity, lobular histology and N-staging. Positive CTC-status was associated with poor OS overall in late-stage (III and IV) (HR 1.477, 95% CI: 1.129-1.931, p = 0.004) but not early-stage BC (0, I, II) (p = 0.110) disease. DTC-status was not associated with OS in early-stage or late-stage subsets. In hormone receptor (HR)-positive disease, chemotherapy was associated with better OS when CTC-status was also positive both in early-stage (p = 0.003) and late-stage (p = 0.023) disease. In a subset of the same BC subtype with negative CTC-status, however, chemotherapy conferred no survival benefit (p = 0.638 for early-stage, p = 0.501 for late-stage). DTC status was not a significant predictor of chemotherapy efficacy in early or late-stage, HR+ disease. Conclusions: This study suggests that CTC-status is a stronger prognostic factor at later stages of BC; yet it can also help guide management of early-stage disease as it appears predictive for chemotherapy benefit.

Abstract P4-01-04: The distribution and prognostic significance of circulating tumor cells are different in invasive lobular carcinoma compared to invasive ductal carcinoma of the breast

Abstract Background: Circulating tumor cells (CTCs) have repeatedly been shown to carry independent prognostic information in metastatic breast cancer (MBC). A CTC count of 5 cells per 7.5 mL blood is a generally accepted cut-off, where MBCs with &amp;lt;5 CTCs are classified as MBCindolent and ≥5 CTCs as MBCaggressive. Furthermore, several studies have shown that the presence of CTC clusters add prognostic information to CTC count alone. Invasive lobular carcinoma (ILC) is the second most common histological breast cancer (BC) type (~10%). The vast majority of all BCs (~80%) are classified as invasive ductal carcinoma (IDC). Many distinguishing clinicopathological and genomic features have been identified between these two types, but in spite of this, current clinical management strategies and treatments are similar and mainly based on studies dominated by IDCs. The aim of this study was to explore potential differences in the distribution and prognostic significance of CTC count and CTC clusters in metastatic ILC vs. IDC, in a prospective observational study. Patients and methods: Between April 2011 and June 2016, 139 women with newly diagnosed metastatic ILC (N=28) and IDC (N=111) were included. CTCs and CTC clusters were detected, using CellSearch technology (Menarini Silicon Biosystems), at baseline (BL) before first-line systemic therapy, and during the first 6 months of follow-up (FU). The primary endpoint was progression-free survival (PFS) and the secondary endpoint overall survival (OS). Median FU time was 49 (27-93) months. Results: There was a highly significant (P&amp;lt;0.001) difference in the median CTC count between ILC (70, range 0-2598) and IDC (2, range 0-668) at BL, and presence of CTC clusters was also higher (36% vs. 18%, P=0.07). These differences between ILC and IDC persisted in the luminal A-like subgroup. The CTC count and CTC clusters declined in both ILC (median count 4, range 0-85; clusters: 4%) and IDC (median count 0, range 0-263; clusters: 12%) after 1 month of systemic treatment, but the decline was most pronounced in ILC. Seventy-nine percent of the ILCs and 46% of the IDCs were classified as MBCaggressive (CTC ≥5) at BL (P=0.003). The prognostic value of CTC ≥5 on PFS (HR 1.5, 95% CI 0.55-4.0, P=0.44) and OS (HR 2.4, 95% CI 0.71-8.3, P=0.16) in ILC was weak, whereas significant prognostic effects were seen in IDC (PFS: HR 1.7, 95% CI 1.2-2.6, P=0.007; OS: HR 2.1, 95% CI 1.3-3.3, P=0.002). With higher cut-offs the prognostic impact of CTC count on PFS/OS was significant also in ILC (CTC ≥20: HR 3.0, 95% CI 1.3-6.8, P=0.01 / HR 3.1, 95% CI 1.2-8.3, P=0.02) (CTC ≥80: HR 3.6, 95% CI 1.5-8.8, P=0.004 / HR 5.9, 95% CI 2.0-17.8, P=0.002) and the prognostic effect in IDC remained. The presence of ≥1 CTC cluster was a negative prognostic factor significantly associated with impaired survival in ILC (PFS: HR 4.6, 95% CI 1.7-12.4, P=0.003; OS: HR 4.9, 95% CI 1.7-13.8, P=0.003), whereas the effect was weaker in IDC (PFS: HR 1.2, 95% CI 0.69-2.0, P=0.55; OS: HR 1.9, 95% CI 1.1-3.3, P=0.02). First-line systemic treatment was similar in ILC vs. IDC (endocrine 46% vs. 39% and chemotherapy 54% vs. 61%) and the overall prognosis did not differ (PFS: HR 0.89, 95% CI 0.57-1.4, P=0.59; OS: HR 0.99, 95% CI 0.60-1.6, P=0.96). Conclusions: In this study of metastatic ILC and IDC, the CTC count at BL was remarkably higher in ILCs and the presence of CTC clusters was also more common, in spite of the fact that no difference in prognosis was seen. The prognostic value of the generally accepted CTC cut-off (≥5) was clearly weaker and the presence of CTC clusters stronger in ILC vs. IDC. A higher cut-off might be more suitable in ILCs in order to better discriminate between MBCindolent and MBCaggressive forms, and CTC clusters could potentially add prognostic information. Citation Format: Ulrik Christoffer Narbe, Pär-Ola Bendahl, Kristina Aaltonen, Mårten Fernö, Carina Forsare, Charlotte Levin Tykjær Jørgensen, Anna-Maria Larsson, Lisa Rydén. The distribution and prognostic significance of circulating tumor cells are different in invasive lobular carcinoma compared to invasive ductal carcinoma of the breast [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-01-04.

Prognostic and Predictive Value of Circulating and Disseminated Tumor Cells in Breast Cancer: A National Cancer Database (NCDB) Analysis.

Importance:Our understanding of the utility of circulating tumor cells (CTCs) and disseminated tumor cells (DTCs) as clinical biomarkers continues to evolve.Objective:This study evaluated (1) clinicopathologic factors associated with the presence of CTCs or DTCs, (2) the prognostic value of CTCs or DTCs by disease stage, 3), the value of these biomarkers in predicting the benefit of chemotherapy.Design:This is a retrospective analysis of patients with breast cancer (BC) diagnosed between 2004 and 2016 using the National Cancer Database (NCDB). To evaluate variables associated with the presence of CTCs or DTCs at the univariate level, we used chi-squared and Wilcoxon rank-sum tests. Multivariate logistic regression models were then constructed using significant variables. Consequently, we included CTC or DTC status (i.e. positive or negative) in multivariate, stage-by-stage Cox regression analyses for overall survival (OS). After stratifying by receptor status and staging, we used the Kaplan-Meier method to explore chemotherapy efficacy in CTC- or DTC-positive vs. CTC- or DTC-negative subsets.Results:Factors significantly associated with CTCs were race, progesterone receptor status, HER2 status, histology and AJCC N- and M-staging. Factors associated with DTCs were race, HER2 status, histology and AJCC N-staging. CTCs were associated with poor OS in late-stage (III and IV) but not early-stage (0-II) BC. DTCs were not significantly associated with OS in either context. In hormone receptor (HR)-positive disease, chemotherapy was associated with better OS when CTC status was positive, both in early-stage and late-stage disease. In a subset of patients without CTCs, however, chemotherapy conferred no survival benefit. DTC status was not a significant predictor of chemotherapy efficacy in early or late-stage, HR+ disease.Conclusions:This study suggests that CTC-status is a significant prognostic factor at later stages of BC; yet it can also help guide management of early-stage disease as it appears predictive for chemotherapy benefit.

Circulating tumor cells: a valuable marker of poor prognosis for advanced nasopharyngeal carcinoma

PurposeTo evaluate the prognostic value of circulating tumor cells (CTCs) in nasopharyngeal carcinoma (NPC).MethodsCox’s proportional hazards regression models were used to identify whether CTCs was a poor prognostic factor for NPC. Chi-square tests were used to analyze and compare the distribution characteristics of CTCs in NPC. ROC curve was used to estimate the cut-off point of CTCs. Kaplan-Meier survival analyses were used to observe the prognostic value of CTCs alone and in combined with Epstein-Barr Virus DNA (EBV-DNA).ResultsCTCs was confirmed to be an independent risk factor for poor prognosis of NPC by Cox’s regression models that enrolled 370 NPC cases and took age, gender, EBV-DNA and CTCs as variables. The proportion of CTCs in stage IV NPC was statistically different from that in stage III; the cut-off point of CTCs between stage IV (288 cases) and stage III (70 cases) NPC estimated by ROC curve was 0.5. The prognosis of advanced NPC patients became worse with the increase of CTCs count. The combined detection of CTCs and EBV-DNA could better predict the prognosis of NPC compared with the single detection of EBV-DNA.

1923P - Prognostic value of CTCs in advanced NSCLC patients treated with platinum-based chemotherapy

BackgroundLung cancer is the leading cause of cancer-related mortality worldwide. At diagnosis, 70% of patients present advanced disease being chemotherapy the standard of care. Although, specific tumour biomarkers that allow a better treatment selection and monitoring is absent at the moment. Enumeration and characterization of circulating tumor cells (CTCs) have the potential to perform as a prognostic biomarker for a precision medicine approach to lung cancer care. The present study was conducted to validate the characterization CTCs from patients with advanced Non-small cell lung cancer (NSCLC) as a valuable tool for anticipating the disease evolution and the therapy response. Methods78 patients with advanced NSCLC were enrolled in the study at HGUV and CHUS. EpCAM positive CTCs from these patients were isolated and analysed using both CellSearch technology and a qRT-PCR based approach at different times: at baseline and before the 2nd and 5th cycle treatment. A panel of genes with a relevant role for NSCLC aggressiveness and the resistance to platinum-based treatments were analysed. ResultsFrom all patients included in the study 46% were positive for CTCs using CellSearch system at baseline, showing only 12% of patients ≥5 CTCs. Additionally, patients with ≥5 CTCs showed poor PFS (4.66 vs 7.12 months, p=0.040) and OS (3,9 vs 13.43 months, p<0.001) rates compared with those patients with <5CTCs. In addition, patients with high CTCs levels during treatment also had a more aggressive disease evolution in terms of PFS and OS (p=0.007 and p=0.001, respectively). From the analyzed gene panel, patients with lower CHOKα expression at baseline had increased PFS (7.03 vs. 3.9 months, p=0.009) and OS (11.4 vs. 4.07 months, p=0.001). Furthermore, we found low CHOK α levels as a powerful marker to discriminate patients with a good response to chemotherapy from those that progressed during treatment administration (14.35 vs 5.07 months, respectively, p=0.011). ConclusionsWe demonstrated that quantification and gene expression characterization of CTCs represents an adequate strategy to identify prognostic biomarkers in NSCLC patients Supported by RTC-2014-1532-1 from MINECO and CB16/12/00350-CB16/12/00328 from CIBERONC. Legal entity responsible for the studyFIHGUV. FundingSupported from RTC-2014-1532-1 (Spanish Ministry of Economy, Industry and Competitiveness) and CB16/12/00350 and CB16/12/00328 from CIBERONC. DisclosureAll authors have declared no conflicts of interest.

Circulating Tumour Cells (CTC), Head and Neck Cancer and Radiotherapy; Future Perspectives.

Head and neck cancer is the seventh most common cancer in Australia and globally. Despite the current improved treatment modalities, there is still up to 50–60% local regional recurrence and or distant metastasis. High-resolution medical imaging technologies such as PET/CT and MRI do not currently detect the early spread of tumour cells, thus limiting the potential for effective minimal residual detection and early diagnosis. Circulating tumour cells (CTCs) are a rare subset of cells that escape from the primary tumour and enter into the bloodstream to form metastatic deposits or even re-establish themselves in the primary site of the cancer. These cells are more aggressive and accumulate gene alterations by somatic mutations that are the same or even greater than the primary tumour because of additional features acquired in the circulation. The potential application of CTC in clinical use is to acquire a liquid biopsy, by taking a reliable minimally invasive venous blood sample, for cell genotyping during radiotherapy treatment to monitor the decline in CTC detectability, and mutational changes in response to radiation resistance and radiation sensitivity. Currently, very little has been published on radiation therapy, CTC, and circulating cancer stem cells (CCSCs). The prognostic value of CTC in cancer management and personalised medicine for head and neck cancer radiotherapy patients requires a deeper understanding at the cellular level, along with other advanced technologies. With this goal, this review summarises the current research of head and neck cancer CTC, CCSC and the molecular targets for personalised radiotherapy response.

Abstract P3-01-03: Circulating tumor cells (CTCs) with epithelial to mesenchymal transition (EMT) phenotype are associated with inferior outcome in primary breast cancer

Abstract Background: CTCs comprise heterogenous population of cancer cells with different clinical and biological value. Epithelial-mesenchymal transition (EMT) leads to generation of cells with cancer stem cell properties and increased resistance to chemotherapy and radiation therapy. While the prognostic value of CTCs with epithelial phenotype was repeatedly demonstrated in primary as well as metastatic breast cancer, prognostic value of CTCs with EMT phenotype (CTC_EMT) remained unknown. The aim of this study was to evaluate the prognostic value of CTCs with EMT phenotype in primary breast cancer (PBC) patients. Methods: This study included 432 primary breast cancer patients treated by surgery and adjuvant therapy from March 2012 to February 2015. CTC_EMT were detected before surgery by quantitative RT-PCR assay. Peripheral blood mononuclear cells (PBMC) were depleted of hematopoietic cells using RossetteSepTMnegative selection kit. RNA extracted from CD45-depleted PBMC was interrogated for expression of EMT transcription factors (TWIST1, SNAIL1, SLUG, ZEB1) by qRT-PCR. Patient samples with higher EMT genes transcripts than those of healthy donors (n=60) were considered as CTC positive. Herein, we report the impact of CTC_EMT on disease-free survival (DFS). Results: CTC_EMT were detected in 76 (17.6%) patients. Patients CTC_EMT had significantly inferior DFS compared to patients without CTC_EMT (HR = 2.46, 95%CI 1.29 – 4.68, p = 0.0003). Estimated 2- and 5-year DFS for CTC_EMT negative vs. CTC_EMT positive patients was 93.4% and 85.5% vs. 86.9% and 58.1%, respectively. Prognostic value of CTC_EMT was demonstrated in all subgroups of patients, most pronounced in hormone receptor positive, HER2 negative subgroup. In multivariate analysis, presence of CTC_EMT, axillary nodal involvement and hormone receptor status were independently associated with DFS (Table 1).Presence of CTC_EMT was not associated with any patients/tumor characteristics except p53 status (CTC_EMT were present in 20.7% of p53 negative vs. 12.4% p53 positive tumors, p = 0.04). Conclusions: In this translational study, we demonstrate for the first time the prognostic value of CTC with EMT phenotype in primary breast cancer. Presence of CTC_EMT could lead to better identification of patients with increased risk of recurrence, especially in hormone receptor positive, HER-2 negative primary breast cancer patients. Multivariate analysis of factors associated with disease free survivalVariableHR (95%CI)P – valueCTC with EMT phenotype Present vs. absent2.46 (1.48-4.10)0.0005N stage N+ vs.N02.92 (1.78-4.76)0.00001ER/PR status Positive for either vs. Negative for both0.40 (0.23-0.71)0.001 Citation Format: Mego M, Jurisova S, Karaba M, Minarik G, Benca J, Sedlackova T, Pindak D, Cristofanilli M, Reuben JM, Mardiak J. Circulating tumor cells (CTCs) with epithelial to mesenchymal transition (EMT) phenotype are associated with inferior outcome in primary breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-01-03.

Dynamic evaluation of circulating tumour cells in patients with advanced gastric and oesogastric junction adenocarcinoma: Prognostic value and early assessment of therapeutic effects

BackgroundThe identification of dynamic biomarkers in advanced gastric and oesogastric junction adenocarcinoma (GOA) could help to tailor strategies for each patient. Enumeration of circulating tumour cells (CTCs) is approved by the US Food and Drug Administration in breast, colon and prostate cancer but is not in advanced GOA. Our study aims to establish the optimal threshold and the clinical significance of CTC count in advanced GOA before and during treatment. MethodsOne hundred six patients with untreated advanced GOA were included in the ancillary study of the PRODIGE 17-ACCORD 20 trial. CTCs were detected in the peripheral blood using the CellSearch system on day 0 (D0) and day 28 (D28). The prognostic value of CTCs at D0 and D28 was analysed by testing several thresholds. ResultsAt baseline, median CTC count was 1 (range, 0–415). While CTCs ≥1, 2 or 3 at D0 were all significantly associated with worse overall survival (OS) and progression-free survival (PFS), CTCs ≥2 were the optimal threshold, on D0 or D28. CTCs ≥2 at D28 were also predictive of disease control. Taking into account both D0 and D28 CTC count defined 3 groups (low/low, high/low and low-high/high) with significantly different PFS (p = 0.0002) and OS (p = 0.003). ConclusionQuantification of CTCs at baseline and during treatment may be a useful prognostic tool in advanced GOA, as it is associated with worse PFS and OS. A threshold ≥2 CTCs seems to have the best discriminant value. Change in CTC count between baseline and D28 could help to tailor treatment to each individual patient.

Detection of Circulating Tumor Cells and Circulating Tumor Microemboli in Gastric Cancer

PURPOSE: Gastric cancer studies indicated a potential correlation between circulating tumor cells (CTCs) in peripheral blood and tumor relapse/metastasis. The prevalence and significance of circulating tumor microemboli (CTM) in gastric cancer remain unknown. We investigated the prevalence and prognostic value of CTCs and CTM for progression-free survival (PFS) and overall survival (OS) in gastric cancer patients. METHODS:Eighty-one gastric cancer patients consented to provide 5ml of peripheral blood before systematic therapy. CTCs and CTM were isolated using isolation by size of epithelial tumor cells and characterized by cytopathologists. For 41 stage IV gastric cancer patients, CTM was investigated as a potential biomarker to predict prognosis. RESULTS:CTCs were detected in 51 patients; the average count was 1.81. In clinical stage I, II, III, and IV patients, the average CTC counts were 1.40, 0.67, 1.24, and 2.71, respectively. CTM were detected in 3 of 33 clinical stage I to IIIb patients, at an average of 0.12 (0-2). CTM were detected in 13 of 53 clinical stage IIIc to IV patients, at an average of 1.26 (0-22). In stage IV patients, CTM positivity correlated with the CA125 level. PFS and OS in CTM-positive patients were significantly lower than in CTM-negative patients (P<.001). CTM positivity was an independent factor for determining the PFS (P=.016) and OS (P=.003) of stage IV patients in multivariate analysis. Using markers of the epithelial-mesenchymal transition, single CTCs were divided into three phenotypes including epithelial CTCs, biphenotypic epithelial/mesenchymal CTCs, and mesenchymal CTCs. For CTM, CK−/Vimentin+/CD45− and CK+/Vimentin+/CD45− phenotypes were observed, but the CK+/Vimentin−/CD45− CTM phenotype was not. CA125 was detected in gastric cancer cell lines BGC823 and MGC803. CONCLUSIONS: In stage IV patients, CTM positivity was correlated with serum CA125 level. CTM were an independent predictor of shorter PFS and OS in stage IV patients. Thus, CTM detection may be a useful tool to predict prognosis in stage IV patients.

Association of changes in circulating cell-free plasma DNA (cfDNA) and circulating tumor cells (CTC) during treatment with clinical outcome from olaparib in castration-resistant prostate cancer (CRPC): Exploratory analyses from the TOPARP-A trial.

141 Background: Response biomarkers are needed to optimize treatment switch decisions in CRPC patients. CTC and cfDNA may have clinical utility as response biomarkers; we studied them during olaparib treatment in a phase II trial in CRCP (Mateo et al NEJM 2015). Methods: CTC were enumerated using CellSearch (Jannsen Diagnostics) and cfDNA was extracted with the QIASymphony circulating DNA kit (Qiagen) from blood samples taken at baseline, 4- and 8-weeks (wk) of therapy. Radiological progression-free survival (rPFS) was defined as time from starting treatment to progression by RECIST 1.1, bone scan (PCWG2) or death. Overall survival (OS) was defined as time from starting treatment to death. CTC changes were categorized based on conversion from ≥ 5 to &lt; 5 CTC/7.5ml blood and on ≥ 30% decline (Lorente et al Eur Urol 2016). cfDNA changes were evaluated as percentage change from baseline (continuous and binary). The prognostic value of CTC and cfDNA changes were assessed by Landmark analysis and Cox models with time-varying covariates; p-value &lt; 0.01 were considered significant to account for multiple tests. Results: Overall, 13/47 (28%) and 16/42 (38%) evaluable patients had a CTC conversion at 4- and 8-wk respectively. A CTC conversion after 4-wk of olaparib associated with longer rPFS (median 8.9 vs 2.7 months [m], p = 0.001); a similar association was found at 8-wk. A 30% CTC decline at 4-wk also associated with longer rPFS (median 4.4 vs 2.6 m, p = 0.004). CTC conversion as a time-varying covariate associated with longer OS (HR 0.26, 95%CI 0.14-0.50, p &lt; 0.001). Median baseline cfDNA was 31.6 ng/ml (IQR 19.4-57.1); 46 and 42 patients were evaluable for cfDNA changes at 4- and 8-wk. Percentage changes in cfDNA at 4- and 8- wk associated with rPFS (HR 1.01 and 1.005; p = 0.005 and 0.002 respectively) but association with OS was not significant. cfDNA declines ≥ 50% at 8- wk associated with longer rPFS (median 8.9 vs 2.7 m, p = 0.007) and OS (17.0 vs 10.1 m, p = 0.004). Conclusions: Decreases in CTC counts and cfDNA concentration associate with improved outcome from olaparib (rPFS, OS) in the TOPARP-A trial. Clinical trial information: NCT01682772.

Abstract P1-01-16: Circulating tumor cells (CTCs) biomarker evaluation from patients with metastatic breast cancer (MBC) utilizing the TargetSelectorTM platform

Abstract Background: Circulating blood biomarkers represent the promise of non-invasive, real-time surrogates for tumor tissue-based biomarkers as well as afford monitoring opportunities over the course of therapy as tumors evolve and acquire resistance to treatment. Circulating tumor cells (CTCs) are cells that disseminate from tumors and can be identified in peripheral blood. CellSearch® is an FDA approved methodology for detecting and enriching this rare CTC population. The prognostic value of CTCs has been established, however the potential to characterize biomarkers on CTCs to inform treatment decisions remains an active area of investigation. Among the emerging platforms for detection and characterization of CTCs is the TargetSelectorTM system. While CellSearch® is limited to capture and detection of epithelial derived CTCs based on EpCAM and cytokeratin (CK) respectively, Biocept's TargetSelectorTM platform utilizes a novel microfluidic system for CTC enrichment based on an antibody capture cocktail that allows for enumeration of CTCs with variable phenotypes (including CK- CTCs). The CTCs are captured in transparent microfluidic chambers and cells can be viewed in situ by fluorescence microscopy and analyzed via immunocytochemistry (ICC), fluorescence in situ hybridization (FISH) and PCR analyses. Methods: Sixty-one patients with metastatic breast cancer consented and provided blood for utilization in the TargetSelectorTM platform. Based on the molecular analysis of tissue biopsies, 92% of these patients had ER+ breast tumors. Biomarker expression on captured CTCs was determined by ICC for ER and by FISH for HER2. Concordance between these results and biomarker expression on archival tumor tissue from these patients was calculated. Results: CTCs were detected in 60 of 61 patient blood samples (range 2–4471); 68% had both CK+ and CK- CTCs, and 32% had only CK- CTCs. None had only CK+ CTCs. Of those with CK+ CTCs, concordance for ER expression between the tissue and blood analyses was 85% (35/41). Concordance was much lower for patients with only CK- CTCs (32%, 6/19). Concordance for HER2 amplification in CK+ patients was 93% (38/41), and 68% (13/19) in CK- patients. For this study, the liquid biopsy was obtained over an extended period of time from when solid tumor ER and HER2 assessments were obtained; this latency period may have influenced concordance levels. For HER2, there was a significantly longer time interval between biopsies for non-concordant than for concordant pairs of samples (58.1 ± 19.7 vs. 30.9 ± 4.3 months) regardless of the CK status. No such difference was seen for the ER analysis. Conclusions: In this exploratory analysis of 61 patients with MBC, we observed a high rate of detectable CTCs as well as CTC concordance for ER (85%) and HER2 amplification (93%) for patients who had CK+ CTCs. Concordance was less if patients only had CK- CTCs. This may be attributable to heterogeneity in the breast cancer phenotypes associated with these CK- CTCs in addition to inherent issues with testing cell surface markers in this population of cells. The variable latency between the between the collection of tissue and blood samples for these analyses may account for the discrepancies observed. Citation Format: Hamilton EP, Yardley DA, Burris III HA, Shastry M, Huynh L, Bhikha L, Singh VM. Circulating tumor cells (CTCs) biomarker evaluation from patients with metastatic breast cancer (MBC) utilizing the TargetSelectorTM platform [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-01-16.

Formation mechanism of circulating tumor cells and progress of its application in I-III stage colorectal carcinoma

It has been a problem in clinical practice that high recurrence and poor survival of patients with colorectal cancer undergoing surgery. As an easy-accessible, repetitive, non-invasive "liquid biopsy" technology, circulating tumor cells(CTC) can assist us in many fields, for instance, real-time monitoring tumor status and providing information about recurrence and prognosis of colorectal cancer. In this review, generation mechanism and relevant major regulation molecules of CTC will be elucidated, and principles, superiorities and inferiorities among different detection technologies were compared. Besides, clinical application and prognostic value of CTC in stage I-III colorectal caner were discussed, and the dilemma of low detection rate of CTC will be tried to solve as well.

Effect of circulating tumor cells (CTCs) on metastatic progression in colorectal cancer.

e22026 Background: The purpose of the study was to analyze the content and to assess prognostic value of CTCs in peripheral blood of colorectal cancer patients with liver metastases. Methods: 75 co...