Positive Circulating Tumor Cells Research Articles

Abstract PO5-18-04: Effect of Digoxin on clusters of circulating tumor cells in patients with metastatic breast cancer (DICCT)

Abstract Background: The presence of circulating tumor cell (CTC) clusters is associated with tumor progression and with a bad prognosis in various cancer types1,2. In breast cancer, a pre-clinical model demonstrated that Na/K-ATPase inhibitors such as digoxin could dissolve CTC clusters and reduce metastasis3. DICCT is a single-arm, therapeutic exploratory phase I study aimed to examine whether digoxin can disrupt CTC clusters in metastatic breast cancer patients (NCT03928210). Material and methods: Metastatic breast cancer patients in whom clusters of CTCs have been detected were eligible. Patients with concomitant heart disease were excluded. After progressive disease in any line of therapy, a window of opportunity before initiation of subsequent systemic therapy was used to administer digoxin treatment for seven (7) days. For CTC detection, blood samples were processed with the FDA-cleared Parsortix system (ANGLE plc, UK). Captured CTCs were stained for EPCAM, HER2, EGFR (positive CTC selection) and CD45 (exclusion marker). To gain insight into the cluster-dissolution ability of digoxin, the primary endpoint was size of CTC clusters (i.e. number of cells within each cluster) under digoxin therapy. The cumulative effect of digoxin treatment on the primary endpoint was assessed by a linear regression model. Results: Nine (9) patients with CTC clusters detected at baseline were enrolled. A target level of digoxin above 0.7 ng/ml could be confirmed at day 7 for all patients. For quantitative and qualitative analysis of CTC clusters, 5.5 to 27 ml of blood were analyzed at baseline, at day 0 pre-treatment, and post 2 hours, 3 days and 7 days of digoxin treatment. The average cluster size ranged between 2 and 11.8 cells (median 2.9) considering all samples from all patients. Digoxin treatment reduced cluster size in 8 patients (88.9%) to different extents, and the proportion of CTC cluster over single CTCs was also reduced in 6 patients (66.7%). The effect of digoxin was evident in both homotypic (cancer cells only) and heterotypic (aggregates of CTCs and white blood cells) clusters. The treatment was well tolerated, and no adverse events related to the study treatment occurred. All patients completed the treatment according to the protocol. Conclusion: DICCT provides the first-in-human proof-of-principle that digoxin induces a partial dissolution of CTC clusters in patients with metastatic breast cancer at drug levels that are safe and well tolerated. Conceptualization of follow-up trials including Na/K-ATPase inhibitors and patient outcome endpoints are underway.

Abstract PO3-16-02: Trastuzumab and taxane chemotherapy in the first-line in MBC patients with a HER2-negative primary tumor and HER2-positive circulating tumor cells: a phase II trial

Abstract Purpose: HER2 overexpressing circulating tumor cells (CTCs) are observed in up to 20% of HER2-negative metastatic breast cancer patients. Since targeted anti-HER2 therapy has drastically increased the outcome of patients with HER2 positive breast cancer, we hypothesized that patients with HER2 overexpressing CTCs might benefit from the addition of trastuzumab to chemotherapy. Methods: In this single-arm, phase II trial, HER2 negative patients with HER2-positive CTCs received trastuzumab as addition to first-line treatment with taxane chemotherapy (trastuzumab group). Patients with detectable CTCs but without HER2 overexpression and that received taxane chemotherapy only, were used as internal control group (taxane monotherapy group). The primary outcome measure was progression-free rate at 6 months (PFR6). The study was powered to reach a PFR6 of 80%; in this case this strategy was considered worth further investigation. In November 2022, the study was terminated early due to slow patient accrual. Results: 63 HER2 negative patients with metastatic disease were screened, of which 8 patients had HER2-positive CTCs and were treated in the first line with trastuzumab in addition a taxane. Patients receiving taxane monotherapy were used as a control group (n = 27). The median number of CTCs was 15 (range 1 – 131) in patients with HER2-positive CTCs, compared to median 5 (range 1-1047) in the control group. PFR6 was 50% in the trastuzumab group and 64% in the taxane monotherapy group, with no significant difference in median PFS (8 versus 9 months, p=0.51). Excluding the patients that had no measurable CTCs, there was a borderline significant difference between median CTC count in the patients that did and that did not have HER2 positive CTCs (p=0.05). We confirmed a significant higher CTC-count in samples that had at least one HER2-postive CTC in an independent patient set (n=233, p< 0.001). Conclusions: Although this study was performed in a limited number of patients, no clinical benefit of trastuzumab was observed. Firstly, we conclude that our strategy was not feasible for clinical implementation due to high numbers needed to screen. And, second, due to the strong correlation between CTC numbers and detected CTC HER2 positivity, the prognostic value of the CTC numbers precludes judgement of any predictive value of the HER2 status of CTCs. Citation Format: Noortje Verschoor, Manouk Bos, Inge de Kruijff, Ngoc M Van, Jaco Kraan, Jan Drooger, Johanna Zuetenhorst, Saskia M Wilting, Stefan Sleijfer, Agnes Jager, John WM Martens. Trastuzumab and taxane chemotherapy in the first-line in MBC patients with a HER2-negative primary tumor and HER2-positive circulating tumor cells: a phase II trial [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-16-02.

The Presence of Small-Size Circulating Tumor Cells Predicts Worse Prognosis in Non-Small Cell Lung Cancer Patients.

Most patients with non-small cell lung cancers (NSCLC) are diagnosed at advanced stages. The 5-year survival rate of patients with advanced lung cancer is less than 20%, which makes lung cancer the leading cause of cancer-related deaths worldwide. To identify indicators that can predict the prognosis of lung cancer patients. To determine the correlation between circulating tumor cells (CTCs), circulating tumor-derived endothelial cells (CTECs), and their subtypes and the prognosis of patients with NSCLC, 80 patients with lung cancer were recruited and 48 patients who met the enrollment criteria were selected in this study. Peripheral blood was collected from the enrolled patients before any treatment and analyzed by the subtraction enrichment and immunostaining-fluorescence in situ hybridization technique to determine the correlation between CTCs and CTECs and lung cancer disease progression and to identify prognostic indicators. In all patients, the positive rate of CTCs was 100% and the positive rate of CTECs was 81.3%. The CTEC positivity rate was higher in late-stage patients than in early-stage patients (P = .03). Patients with advanced or lymph node metastases had a higher rate of small-size CTC positivity than those with early or no lymph node metastases. Large-size CTEC positivity was higher in patients with advanced NSCLC than in early-stage patients. Patients with ≥1 small-size CTC had shorter progression-free survival, and it was an independent prognostic factor. Small-size CTCs are a reliable prognostic indicator and a probable predictor of the severity of disease in NSCLC patients.

Abstract CT223: Dormancy reprograming therapy of 5-azacitidine (AZA) and all-trans retinoic acid (ATRA) in biochemically recurrent prostate cancer

Abstract Microenvironmental signals and epigenetic changes can instruct proliferative disseminated tumor cells to enter dormancy. The combination of Azacitidine (AZA) and All-trans retinoid acid (ATRA) can reprogram active prostate cancer (PCa) cells into a dormant state. Herein, we evaluated the safety and clinical activity of AZA + ATRA in patients (pts) with biochemically recurrent PCa. Eligible pts were those with diagnosis of PCa post-local therapy with rising PSA (PSADT < 10 mo). Pts were excluded if they had radiographic evidence of disease or if they were a candidate for salvage radiation therapy (RT). Eligible pts were randomized 1:1 to arm A vs. B. All pts received Lupron 7.5 mg IM at the start of study. Four weeks later, pts entered a 24-week treatment (tx) phase. Pts in arm A received AZA 40 mg/m2 SQ x 5 days and ATRA 45 mg/m2 PO x 5 days Q4W for 12 weeks (w), followed by 12w of observation. Pts in arm B underwent 12w of observation, followed by 12w of AZA and ATRA at same dosing as arm A. All pts underwent follow up until initiation of next tx. The primary endpoint was safety and tolerability as assessed by CTCAE v5.0. Key secondary endpoints included % of pts with prolongation of PSADT pre- and post-tx and time to next treatment (TTNT). Levels of dormancy biomarkers, BMP4 and BMP7, were quantified using ELISA. Circulating tumor cells (CTCs) were analyzed for positive expression of NR2F1 using immunofluorescence. Wilcoxon signed rank test was used for comparing the PSADT. All statistical analysis was performed in R. Fourteen pts were enrolled (A: N=6, B: N=8) with a median age of 66 (range 54-77). At baseline, mean PSA was 4.75 ng/ml (A: 7.11, B: 2.99) and mean PSADT was 2.89 months (A: 3.51, B: 2.43). Eight (57.1%) pts had a Gleason score > 8 at initial diagnosis (A: 83.3%, B: 37.5%). There were no reported Grade > 3 treatment-related adverse events (TRAEs) and no treatment discontinuations. The most common TRAEs included hot flashes, white blood cell decreased and lymphocyte count decreased (all 8.3% each), and anemia (5.6%). There was prolongation of PSADT pre- and post-tx in 6 (46%) pts, however, overall difference in PSADT was non-significant [p>0.1]. 13 out of 14 (93%) pts had TTNT of > 6 months. One pt developed radiographic progression prior to completion of tx phase and a total of 6 pts (42.8%) within 3 months of tx phase. Out of 8 pts, 37.5% and 75% of pts showed increased levels of BMP4 and BMP7 respectively. Upon tx, CTC count decreased in 3 out of 5 pts analyzed, while CTCs were undetectable in two pts. Upon tx, NR2F1 expression could not be detected due to non-detection of CTCs, except for one pt who showed 100% NR2F1 positive CTCs in follow up. AZA + ATRA appears safe and well tolerated, and there was clinical activity in a small subset of pts potentially correlated with dormancy. Additional prospective clinical studies are needed to elucidate dormancy mechanisms further and optimize dosing strategy. Citation Format: Vaibhav G. Patel, Deepak Singh, Himanshu Joshi, Bobby Liaw, Che-Kai Tsao, Matthew Galsky, Lindsay Diamond, Julio Agguire-Ghiso, William Oh. Dormancy reprograming therapy of 5-azacitidine (AZA) and all-trans retinoic acid (ATRA) in biochemically recurrent prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT223.

Abstract 7043: Genomic profiling of DLL3-positive and negative CTCs in small cell lung cancer

Abstract BACKGROUND: Delta-like ligand 3 (DLL3), an atypical Notch family protein implicated in neuroendocrine tumorigenesis, has emerged as a promising therapeutic target in small cell lung cancer (SCLC), prompting numerous clinical trials investigating DLL3-targeted treatments. Exploring DLL3 in circulating tumor cells (CTCs) through liquid biopsy, coupled with comprehensive genomic analysis, presents an invaluable and minimally-invasive avenue for monitoring disease progression. This approach holds the potential to tailor personalized treatment strategies, emphasizing the critical need for in-depth investigations into both DLL3-positive and negative cell genomic compositions. METHODS: This study examined blood collected in CellSave preservative tubes from stage I (n=17) and stage IV (n=12) SCLC patients, as well as healthy donors (n=10). The CELLSEARCH® platform was employed to count EpCAM-enriched CTCs and evaluate DLL3 protein expression. Subsequently, individual CTCs were isolated based on the presence and absence of DLL3 expression using the DEPArray™ PLUS. The isolated DLL3-negative and positive CTCs were subjected to low-pass sequencing using the Ampli1™ LowPass Kit to uncover genomic aberrations. RESULTS: CTCs were absent in the healthy control group. In stage I patients, CTCs were identified in 5.8% of blood samples, while in stage IV patients, they were present in 50% of samples, with an average CTC count of 148 in stage IV. Among a total of 2074 detected CTCs, 460 were DLL3-positive, accounting for 6-28% of EpCAM-enriched CTCs in individual patients. Analysis of >300 copy number alteration (CNA) profiles of sorted single cells revealed considerable inter-patient and intra-patient heterogeneity, delineating recurrent clonality and specific genomic alterations in DLL3-negative CTCs. In contrast, DLL3-positive cells showed more stochastic CNA profiles, suggestive of apoptosis-related DNA fragmentation. CONCLUSIONS: Integrating CellSearch, DEPArray, and low-pass sequencing provides a minimally-invasive approach to compare genomic characteristics in DLL3-positive and negative CTCs from SCLC patients. Extension of this approach to a larger patient cohort and employing machine learning algorithms will facilitate identification of patterns within diverse CNA profiles, improving patient stratification and predicting treatment responses for personalized therapeutic strategies in SCLC. Citation Format: Zoltan Simandi, Thai Bui, Alberto Ferrarini, Steven Hepburn, Richard G. Del Mastro. Genomic profiling of DLL3-positive and negative CTCs in small cell lung cancer [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 7043.

Abstract 3707: Characterization of estrogen receptor expression on CTCs during CDK4/6i treatment in HR+/HER2- metastatic breast cancer: Results from the PACE phase II study

Abstract Background Circulating tumor cells (CTCs) are associated with worse survival in metastatic breast cancer (MBC). The PACE study (NCT03147287) enrolled patients (pts) with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) MBC after progression on CDK4/6 inhibitor (CDK4/6i) and endocrine therapy, and randomized pts to fulvestrant (ful) alone; ful with palbociclib; or ful, palbociclib, and avelumab [Mayer et al., SABCS 2022]. Pts with ≥5 CTCs appear to derive benefit from treatment combinations vs ful alone. In this feasibility analysis, we evaluated estrogen receptor (ER) expression on CTCs to further investigate their monitoring/predictive potential.Methods Blood samples were collected from pts enrolled in the PACE study at: baseline (T1), first tumor assessment (T2) and progression (T3). CTCs were enumerated using the CellSearch platform and samples were classified as CTChigh or CTClow (cutoff ≥5 CTCs). CTChigh samples underwent ER expression quantification with the ACCEPT software [Zeune et al. 2017]. ER expression intensity (ERint) was measured through the Marker Characterization function for each CTC; the average was calculated for each sample. Results From the 220 enrolled pts, a total of 409 samples (166, 153 and 90 collected at T1, T2, and T3, respectively) were analyzed for ER. Overall, 236 samples were CTClow (T1 = 91, T2 = 97, T3 = 48) and 173 were CTChigh (T1 =75, T2 =56, T3 =42). ER was quantified on 3928, 1853, and 2209 CTCs collected at T1, T2, and T3, respectively. Overall, 32.2% of CTCs were ER negative (ER-).The samples’ median ERint showed a numerical decrease from T1 to T3 (T1 = 7.27, T2 = 4.58, T3 = 1.31). Similarly, the % of ER positive (ER+) CTCs per sample decreased from baseline to progression: 26.3%, 14.0%, 5.5% at T1, T2, T3, respectively.CTChigh samples were then classified as ER+ or ER- (ER+ = mean ER_int >0). At T1, 91 (54.8%) samples were CTClow, 67 (40.4%) were CTChigh/ER+, and 8 (4.8%) were CTChigh/ER-. At progression, 48 (53.3%) samples were CTClow, 26 (28.9%) were CTChigh/ER+, and 16 (17.8%) samples were CTChigh/ER-. A numerical increase in the proportion of CTChigh/ER- samples was thus observed from baseline to progression (4.8 to 17.8%).Conclusions Herein we demonstrated the feasibility of evaluating and quantify ER expression on CTCs with a software-assisted approach to reduce inter-operator variability. In the PACE study, ER expression on CTCs was decreased at progression compared to baseline, possibly suggesting a mechanism associated with treatment resistance. Future analyses are needed to investigate the correlation between ER expression levels on CTCs with survival and treatment response. This, together with information about the mutational status of ESR1 by ctDNA sequencing, might provide a new perspective on the development of resistance to ful and CDK4/6i in HR+/HER2- MBC. Citation Format: Mara Serena Serafini, Carolina Reduzzi, Lorenzo Gerratana, Rinath Jeselsohn, Reshma L. Mahtani, Cynthia X. Ma, Angela DeMichele, Jane Lowe Meisel, Kathy D. Miller, Yara Abdou, Elizabeth C. Riley, Rubina Qamar, Priyanka Sharma, Sonya Reid, Harold J. Burstein, Sara M. Tolaney, Michelle K. DeMeo, Yuan Liu, Eric Gauthier, Yue Ren, Meredith M. Regan, Huiping Liu, Erica L. Mayer, Massimo Cristofanilli. Characterization of estrogen receptor expression on CTCs during CDK4/6i treatment in HR+/HER2- metastatic breast cancer: Results from the PACE phase II study [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 3707.

Abstract 7487: Construction of a reliable CTC detection method and validity evaluation of CTC markers in colorectal cancer

Abstract Even in modern times when medical technology has advanced, cancer remains a life-threatening disease, and recurrence and metastasis are major issues in cancer treatment. The characteristics of cancer cells change with progression and treatment. Therefore, timely evaluation on their characteristics and decision on the treatment strategy are required. Circulating tumor cells (CTCs) are released into blood vessels in solid tumors and promote metastasis by circulating in the blood. CTCs are thus attractive targets for liquid biopsy and can provide useful information for selection of appropriate treatment. To obtain reliable results from CTC testing, it is important to prove that the detected cells are derived from cancerous tissue. In molecular tests targeting CTCs, it is still unclear whether the detected cells are derived from cancer tissue displaying genetic mutations. Aiming to establish reliable CTC testing, we have developed a simple method using molecular imaging flow cytometry to detect APC gene mutation together with Cytokeratin and Vimentin, which are epithelial-mesenchymal transition markers. Since, abnormalities in the APC gene are detected in 60-70% of colorectal cancer patients, detecting such mutations provides strong evidence that the detected cells are derived from cancerous tissue. Here, we show that upon evaluation of analytical performance of our method using cells isolated from cancerous tissue, our method showed high concordance rate against APC gene mutation. A clinical proof-of-concept using 5 mL of whole blood from colorectal cancer patients revealed that counts of cells with APC mutation in blood and cells with Cytokeratin and/or Vimentin expression in blood are highly correlated. Our results demonstrated a pathological stage-dependent increase in the count and frequency of Cytokeratin and/or Vimentin positive CTCs. We believe that our study not only establishes a practical approach for identifying CTCs in cancer patients but also provides potential implications in clinical practice, prognostic evaluation, and selection of treatment strategies. Citation Format: Yusuke Takahashi, Yuichi Ijiri, Shiki Fujino, Nakhaei Elnaz, Ayuko Kishimoto, Kentaro Shirai, Shigeki Iwanaga, Masatoshi Yanagida, Ali Asgar Bhagat, Norikatsu Miyoshi. Construction of a reliable CTC detection method and validity evaluation of CTC markers in colorectal cancer [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 7487.

Clinical value of circulating tumour cells in evaluating the efficacy of continuous hepatic arterial infusion among colorectal cancer patients

Few studies have been conducted to evaluate the efficacy of HAIC using circulating tumour cells (CTCs). In this study, a total of 100 patients who received HAIC treatment and CTC detection were selected. The results showed that after HAIC treatment, the levels of CTC, carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) decreased. Postoperative progression-free survival (PFS) rates between patients with positive and negative preoperative CTC results, and for CA19-9, CEA were significantly different. The positive rate of CTCs was 61% before chemotherapy and 23% after chemotherapy, and the correlation coefficient between the two was 0.385. Those whose CTC values increased after chemotherapy had shorter PFS rates. CTCs are an independent predictor of recurrence. Patients with CTC-positive results are more susceptible to recurrence. The CTC count in peripheral blood has a close bearing on the postoperative chemotherapy efficacy of patients with CRC and affects patients’ PFS.

Poor patient outcome correlates with active engulfment of cytokeratin positive CTCs within cancer-associated monocyte population in lung cancer.

High rates of mortality in non-small cell lung cancer lung cancer is due to inherent and acquired resistance to systemic therapies and subsequent metastatic burden. Metastasis is supported by suppression of the immune system at secondary organs and within the circulation. Modulation of the immune system is now being exploited as a therapeutic target with immune checkpoint inhibitors. The tracking of therapeutic efficacy in a real-time can be achieved with liquid biopsy, and evaluation of circulating tumour cells and the associated immune cells. A stable liquid biopsy biomarker for non-small cell lung cancer lung cancer has yet to be approved for clinical use. We performed a cross-sectional single-site study, and collected liquid biopsies from patients diagnosed with early, locally advanced, or metastatic lung cancer, undergoing surgery, or systemic therapy (chemotherapy/checkpoint inhibitors). Evaluation of overall circulating tumour cell counts, or cluster counts did not correlate with patient outcome. Interestingly, the numbers of Pan cytokeratin positive circulating tumour cells engulfed by tumour associated monocytes correlated strongly with patient outcome independent of circulating tumour cell counts and the use of checkpoint inhibitors. We suggest that Pan cytokeratin staining within monocytes is an important indicator of tumour-associated inflammation post-therapy and an effective biomarker with strong prognostic capability for patient outcome.

A FACS-based novel isolation technique identifies heterogeneous CTCs in oral squamous cell carcinoma.

Isolating circulating tumour cells (CTCs) from the blood is challenging due to their low abundance and heterogeneity. Limitations of conventional CTC detection methods highlight the need for improved strategies to detect and isolate CTCs. Currently, the Food and Drug Administration (FDA)-approved CellSearch™ and other RUO techniques are not available in India. Therefore, we wanted to develop a flexible CTC detection/isolation technique that addresses the limitation(s) of currently available techniques and is suitable for various downstream applications. We developed a novel, efficient, user-friendly CTC isolation strategy combining density gradient centrifugation and immuno-magnetic hematogenous cell depletion with fluorescence-activated cell sorting (FACS)-based positive selection using multiple CTC-specific cell-surface markers. For FACS, a stringent gating strategy was optimised to exclude debris and doublets by side scatter/forward scatter (SSC/FSC) discriminator, remove dead cells by 4',6-diamidino-2-phenylindole (DAPI) staining, and eliminate non-specific fluorescence using a "dump" channel. APC-labelled anti-CD45mAB was used to gate remaining hematogenous cells, while multiple epithelial markers (EpCAM, EGFR, and Pan-Cytokeratin) and an epithelial-mesenchymal transition (EMT) marker (Vimentin) labelled with fluorescein isothiocyanate (FITC) were used to sort cancer cells. The technique was initially developed by spiking Cal 27 cancer cells into the blood of healthy donors and then validated in 95 biopsy-proven oral squamous cell carcinoma (OSCC) patients. CTCs isolated from patients were reconfirmed by Giemsa staining, immuno-staining, and whole transcriptome amplification (WTA), followed by qRT-PCR. In vitro culture and RNA sequencing (RNA-Seq) were also performed to confirm their suitability for various downstream applications. The mean detection efficiency for the Cal 27 tongue cancer cells spiked in the whole blood of healthy donors was 32.82% ± 12.71%. While ~75% of our patients (71/95) had detectable CTCs, the CTC positivity was independent of the TNM staging. The isolated potential cancer cells from OSCC patients were heterogeneous in size. They expressed different CTC-specific markers in various combinations as identified by qRT-PCR after WTA in different patients. Isolated CTCs were also found to be suitable for downstream applications like short-term CTC culture and RNA-Seq. We developed a sensitive, specific, flexible, and affordable CTC detection/isolation technique, which is scalable to larger patient cohorts, provides a snapshot of CTC heterogeneity, isolates live CTCs ready for downstream molecular analysis, and, most importantly, is suitable for developing countries.

Peripheral arterial rather than venous blood is a better source of circulating tumor cells in early lung cancer.

Circulating tumor cells (CTCs) play a crucial role in the early diagnosis and prognosis of lung cancer. Identification of a more suitable sample source could be a breakthrough towards enhancing CTC detectability in early-stage lung cancer. We investigated the differences in detectable CTCs between peripheral arterial and venous blood in early- and mid-stage lung cancer patients undergoing surgery and analyzed the association between clinicopathological factors and detectable CTCs in peripheral arterial and venous blood. Peripheral arterial and venous blood was collected in 5-mL samples from 56 patients with surgically resected and pathologically clear at early- or mid-stage lung cancer. Blood specimens were enriched for CTCs based on isolation by size of epithelial tumor cells. The CTCs were identified using Swiss Giemsa staining and immunohistochemistry for CD45/CD31. In stage I lung cancer, CTC-positive rate was significantly higher in peripheral arterial than in venous blood (45.45% vs. 17.39%). There was no significant difference in the number of detectable CTCs between peripheral arterial and venous blood. A low degree of differentiation was associated with a high positive rate of CTCs in peripheral venous blood. The number of circulating tumor microemboli was significantly higher in patients with tumor size >3 cm compared with ≤3 cm. CTC levels in peripheral arterial and venous blood differed little in lung cancer patients.Compared to peripheral venous blood, peripheral arterial blood had a higher CTC positivity rate in early-stage lung cancer.This study was favorable for early detection and monitoring of lung cancer.

Self-assembly circular multi-DNA mediated rolling circle amplification for sensitive detection of PD-L1+ circulating tumor cells in the peripheral blood of cancer patients

It has been found that evaluating the status of programmed cell death ligand (PD-L1) in the circulating tumor cells (CTCs) was associated with improved efficacy to anti-PD-L1 inhibitors. However, high-quality detection of PD-L1 positive (PD-L1+) CTCs remains a huge challenge. In this study, we propose a short time, high efficiency and applicability method that fabricated by self-assembly circular multi-DNA (CMD) mediating rolling circle amplification (RCA) for highly sensitive and rapid analysis of PD-L1+ cells. Firstly, a short single-stranded circular DNA which could bind specifically with PD-L1 protein was designed. In addition, CMD were designed as self-assembly which could serve as a template in RCA process. Next, the exponential amplification of DNA was achieved by the rolling circle amplification and the fluorescence signal was detected by using the molecular beacons. The unique CMD mediated rolling circle amplification facilitated quantitative detection of PD-L1+ CTCs in the blood of different cancer patients. To visualize the results of CMD on the target cells, we used confocal microscope to assess PD-L1 expression in MCF-7 (breast cancer), OE33 (esophaguscancer) and HCC827 (lung cancer) cells. The results indicated that the CMD mediating RCA can perfectly combine with different kinds of cells, amplify the signal and the recovery rate was over 99 %. What’s more, we performed clinical tests in the blood of the corresponding patient (14 cases of breast cancer, 15 esophageal cancer and 11 lung cancer). We further quantified the number of CTCs in patient blood through establishing the standard curve and the limit of detection (LOD) was calculated to be 1 cell/mL. Moreover, the ring structure was designed to have replaceable sequence and to realize combining different CTCs surface markers (such as Her-2). This method has the advantages of high sensitivity, good expansibility, low cost and can be completed in a short time as well. Therefore, it is expected to develop a new CTCs typing detection kit and might thus provide reliable diagnostic results to provide individualized treatment strategies.

Frequency and Prognostic Value of Circulating Tumor Cells in Cancer of Unknown Primary.

Cancer of unknown primary (CUP) is defined as a primary metastatic malignancy, in which the primary tumor remains elusive in spite of a comprehensive diagnostic workup. The frequency and prognostic value of circulating tumor cells (CTCs), which are considered to be the source of metastasis, has not yet been systematically evaluated in CUP. A total of 110 patients with a confirmed diagnosis of CUP according to the European Society for Medical Oncology (ESMO) guidelines, who presented to our clinic between July 2021 and May 2023, provided blood samples for CTC quantification using CellSearch methodology. CTC counts were correlated with demographic, clinical, and molecular data generated by comprehensive genomic profiling of tumor tissue. CTCs were detected in 26% of all patients at initial presentation to our department. The highest CTC frequency was observed among patients with unfavorable CUP (35.5%), while patients with single-site/oligometastatic CUP harbored the lowest CTC frequency (11.4%). No statistically significant association between CTC positivity and the number of affected organs (P = 0.478) or disease burden (P = 0.120) was found. High CTC levels (≥5 CTCs/7.5 mL; 12/95 analyzed patients) predicted for adverse overall survival compared to negative or low CTC counts (6-months overall survival rate 90% vs 32%, log-rank P < 0.001; HR 5.43; 95% CI 2.23-13.2). CTC dynamics were also prognostic for overall survival by landmark analysis (log-rank P < 0.001, HR 10.2, 95% CI 1.95-52.9). CTC frequency is a strong, independent predictor of survival in patients with CUP. CTC quantification provides a useful prognostic tool in the management of these patients.

Detection of circulating tumor cells in patients with pancreatic cancer by novel nano microfluidic chips and comprehensive nursing intervention.

It was to explore the detection efficiency of novel nano microfluidic chips on circulating tumor cells (CTCs) in pancreatic cancer (PC) patients and the effect of comprehensive nursing intervention on the life indicators of patients after PC surgery. PC, benign pancreas, and healthy volunteers were enrolled. The number and positive rate of CTCs in the subjects, the relationship between the number of CTCs in PC patients and clinical data, the recurrence rate, and the life indicators of patients after intervention were sorted out and analyzed. The positive rate of CTCs was 96.67% in PC group (29/30), 16.67% in benign pancreas group (5/30), and 0% in healthy controls. The positive CTCs in PC patients were correlated with vascular invasion (P<0.05). The recurrence rate after PC resection was 56.67% (17/30). The positive detection rate of nano microfluidic chip was 30/30 (100%), which was higher than against CellSeach 7/30 (23.33%), P<0.05. The physiological function score of intervention group (93.67±1.48) was higher as against controls (60.45±2.03), P<0.05. The social function score of intervention group (91.26±0.44) was higher as against controls (54.92±2.98), P<0.05. The novel nano microfluidic chip has high sensitivity and specificity for the detection of CTCs in PC patients. Postoperative comprehensive nursing intervention can improve the quality of life (QoL) and functional status of PC patients.

Sensitivity and specificity of folate receptor α-positive circulating tumour cells in gastric cancer.

We aimed to investigate whether folate receptor α (FRα)-positive circulating tumour cells (CTCs) could be used as a noninvasive liquid biopsy approach in gastric cancer (GC). Tissue microarray and bioinformatic analyses were used to evaluate FRα expression in GC. Patients with FRα-positive CTC examinations at our institute between July 2021 and May 2022 were retrospectively evaluated. Receiver operating characteristic curves were used to evaluate the diagnostic performance of FRα-positive CTCs in GC. FRα was highly expressed and associated with poor prognosis in GC based on public database. Data for 163 patients (20 with benign disease and 143 with GC) were retrospectively collected. FRα-positive CTC levels were significantly higher in the GC group than in the benign disease group (12.15 ± 1.47 FU/3ml vs. 10.47 ± 1.63 FU/3ml, P < 0.01). FRα-positive CTC levels were also elevated in GC patients with vessel/neuron invasion or extra-nodal tumour deposits (12.31 ± 1.47 FU/3ml vs. 11.77 ± 1.38 FU/3ml, P = 0.037). Areas under the curve of FRα-positive CTC levels for GC and early GC were 0.774 (P < 0.001) and 0.736 (P = 0.005). With a cut-off value of 10.95 FU/3ml, the Youden indexes for GC and early GC were 0.502 (sensitivity = 85.2% and specificity = 65.0%) and 0.450 (sensitivity = 80.0% and specificity = 65.0%), respectively. FRα-positive CTC detection by noninvasive liquid biopsy is a useful and effective approach for screening of patients with GC.

Evaluation of cell surface vimentin positive circulating tumor cells as a prognostic biomarker for stage III/IV colorectal cancer

Currently, little is known about the phenotypes of circulating tumor cells (CTCs), particularly epithelial and mesenchymal phenotypes, and their impact on the prognosis of colorectal cancer (CRC) patients. This study aims to investigate the CTC phenotypes and their prognostic implications in stage III/IV CRC. Patients who were diagnosed with CRC and underwent CTC detection at two hospitals were included. CTCs were detected using a mesenchymal CTC kit, and the clinical and pathological characteristics of CTCs were compared with those of cell surface vimentin-positive CTCs (CSV-CTCs). Disease-free survival (DFS) was assessed and used as an indicator of CTC phenotype-related prognosis. Univariate and multivariate Cox regression analyses were made to identify risk factors, and nomogram models were employed for prognostic prediction. A total of 82 patients were enrolled, with a CTC detection rate of 86.6%. Among the detected CTCs, 60% were CSV-CTCs. The CSV-CTC count showed a positive correlation with the T-stage, the M-stage, and the location of the primary tumor (P = 0.01, P = 0.014, and P = 0.01, respectively). Kaplan–Meier survival analysis revealed that CSV-CTCs were associated with worse DFS in patients receiving first-line oxaliplatin chemotherapy (hazard ratio (HR) = 3.78, 95% CI 1.55–9.26, p = 0.04). When the cut-off value of the CSV-CTC count was 3, the optimal prognostic prediction was achieved. Compound models considering CSV-CTCs, TNM staging, the site of the primary tumor and the Ras gene status yielded the best results in both the receiver operating characteristic (ROC) analysis and the decision curve analysis (DCA). This study indicates that CSV-CTCs predominate in CTCs of CRC patients, and a count of CSV-CTCs ≥ 3 is an independent risk factor for worse prognosis.

A Novel Filtration Membrane for Clustered Circulating Tumor Cell Extraction: A Prospective Feasibility Study.

Circulating tumor cells (CTCs) have garnered attention as biomarkers for therapeutic response and prognosis in malignant neoplasms. Nonetheless, existing literature predominantly relies on surrogate markers of tumor cells or focuses on single-cell CTC, failing to adequately address the challenge of detecting cluster-forming CTCs, which bear considerable prognostic implications. This prospective study aims to validate the efficacy of a novel filtration membrane, namely Soft Micro Pore Filter (S-MPF®), for rare cell recovery in detecting CTCs through the analysis of clinical samples. Patients with confirmed lung cancer or highly suspected lung cancer based on specific criteria (solid tumor size >2.0 cm, serum carcinoembryonic level >7.5 ng/ml, maximum standard uptake value derived from fluorodeoxyglucose-position emission tomography >2.9) were included in the study. CTCs were extracted from preoperative peripheral arterial blood samples using S-MPF®, and the validity of the filtration system was positively verified. Out of the 25 enrolled patients, 23 had lung cancer. CTC positivity was observed in 17 cases (73.9%), whereas cluster CTC positivity was observed in 16 cases (69.6%), with a median count of two clusters. Single CTC positivity was observed in 11 cases (52.1%), with a median count of one cell. The utilization of the newly developed S-MPF® filtration membrane exhibited a high rate of CTC identification, demonstrating its suitability for clinical applications.

Effect of various hepatectomy procedures on circulating tumor cells in postoperative patients: a case-matched comparative study.

The objective of this study is to elucidate the prevalence of systemic circulating tumor cells (CTCs) prior to and following resection of hepatocellular carcinoma (HCC), and to compare the disparities in postoperative CTCs in terms of quantity and classifications between the open liver resection (OPEN) and laparoscopic liver resection (LAP) cohorts. From September 2015 to May 2022, 32 consecutive HCC patients who underwent laparoscopic liver resection at Southwest Hospital were retrospectively enrolled in this study. The clinicopathological data were retrieved from a prospectively collected computer database. Patients in the OPEN group matched at a 1:1 ratio with patients who underwent open liver resection during the study period on age, gender, tumor size, number of tumors, tumor location, hepatitis B surface antigen (HBsAg) positivity, alpha-fetoprotein (AFP) level, TNM and Child-Pugh staging from the database of patients to form the control group. The Can-Patrol CTC enrichment technique was used to enrich and classify CTCS based on epithelial-mesenchymal transformation phenotypes. The endpoint was disease-free survival (DFS), and the Kaplan-Meier method and multiple Cox proportional risk model were used to analyze the influence of clinicopathological factors such as total CTCs and CTC phenotype on prognosis. The mean age of the 64 patients with primary liver cancer was 52.92 years (23-71), and 89.1% were male. The postoperative CTC clearance rate was more significant in the OPEN group. The total residual CTC and phenotypic CTC of the LAP group were significantly higher than those of the OPEN group (p = 0.017, 0.012, 0.049, and 0.030, respectively), which may increase the possibility of metastasis (p = 0.042). In Kaplan-Meier analysis, DFS was associated with several clinicopathological risk factors, including Barcelona Clinical Liver Cancer (BCLC) stage, tumor size, and vascular invasion. Of these analyses, BCLC Stage [p = 0.043, HR (95% CI) =2.03(1.022-4.034)], AFP [p = 0.007, HR (95% CI) =1.947 (1.238-3.062)], the number of positive CTCs [p = 0.004, HR (95% CI) =9.607 (2.085-44.269)] and vascular invasion [p = 0.046, HR (95% CI) =0.475 (0.22-1.023)] were significantly associated with DFS. In comparison to conventional OPEN technology, LAP technology has the capacity to augment the quantity of epithelial, mixed, and mesenchymal circulating tumor cells (CTCs). Following the surgical procedure, there was a notable increase in the total CTCs, epithelial CTCs, and mixed CTCs within the LAP group, indicating a potential drawback of LAP in facilitating the release of CTCs.

Prognostic Role of Circulating Tumor Cells in Patients with Metastatic Castration-Resistant Prostate Cancer Receiving Cabazitaxel: A Prospective Biomarker Study.

Circulating tumor cells (CTCs) appear to be a promising tool for predicting the clinical outcome and monitoring the response to treatment in patients with solid tumors. The current study assessed the clinical relevance of monitoring CTCs in patients with metastatic castration resistant prostate cancer (mCRPC) treated with cabazitaxel. Patients with histologically confirmed mCRPC who were previously treated with a docetaxel-containing regimen and experienced disease progression were enrolled in this multicenter prospective study. CTC counts were enumerated using the CellSearch system at baseline (before cabazitaxel initiation), after one cabazitaxel cycle (post 1st cycle) and at disease progression (PD). Patients were stratified into predetermined CTC-positive and CTC-negative groups. The phenotypic characterization was performed using double immunofluorescence staining with anti-CKs and anti-Ki67, anti-M30 or anti-vimentin antibodies. The median PFS and OS were 4.0 (range, 1.0-17.9) and 14.5 (range, 1.2-33.9) months, respectively. At baseline, 48 out of 57 (84.2%) patients had ≥1 CTCs/7.5 mL of peripheral blood (PB) and 37 (64.9%) had ≥5 CTCs/7.5 mL of PB. After one treatment cycle, 30 (75%) out of the 40 patients with available measurements had ≥1 detectable CTC/7.5 mL of PB and 24 (60%) ≥ 5CTCs/7.5 mL of PB; 12.5% of the patients with detectable CTCs at the baseline sample had no detectable CTCs after one treatment cycle. The detection of ≥5CTCs/7.5 mL of PB at baseline and post-cycle 1 was associated with shorter PFS and OS (p = 0.002), whereas a positive CTC status post-cycle 1 strongly correlated with poorer OS irrespective of the CTC cut-off used. Multivariate analysis revealed that the detection of non-apoptotic (CK+/M30-) CTCs at baseline is an independent predictor of shorter OS (p = 0.005). In patients with mCRPC treated with cabazitaxel, CTC counts both at baseline and after the first cycle retain their prognostic significance, implying that liquid biopsy monitoring might serve as a valuable tool for predicting treatment efficacy and survival outcomes.

Phenotypic characteristics of circulating tumor cells and predictive impact for efficacy of chemotherapy in patients with pancreatic cancer: a prospective study.

Early chemoresistance and tumor mass progression are associated with poor prognosis in pancreatic ductal adenocarcinoma (PDAC). Circulating tumor cells (CTCs) have been studied as potential predictors of treatment response and prognosis in PDAC; however, this approach has yet to be applied in clinical practice. The aim of our study was to investigate the phenotypic characteristics of CTCs and determine their predictive value for PDAC progression. We prospectively enrolled 40 patients who were pathologically diagnosed with PDAC and collected blood samples at diagnosis, 2 months after diagnosis, and during disease progression or recurrence. We used a microfabricated filter-based enrichment system to retrieve and analyze CTCs, which were classified using immunofluorescence staining (CD45, EpCAM, and vimentin). Our study included 20 women and 20 men (median age, 66 years). Overall, 45% of the patients (18/40) had disseminated disease, and 77.5% (31/40) received chemotherapy. Multivariate analysis revealed that the total CTC count and carbohydrate antigen 19-9 level at 2 months after diagnosis were associated with disease progression (P<0.05). Linear mixed model analysis revealed that the total CTC count and vimentin-positive CTCs were significantly correlated with treatment response during chemotherapy (P=0.024 and 0.017, respectively). Kaplan-Meier analysis showed that total CTC positivity at 2 months was significantly associated with poor progression-free survival (P=0.038). Our study's findings suggest that CTCs can serve as predictive biomarkers of clinical outcomes in patients with PDAC receiving palliative chemotherapy. In particular, the total CTC count and vimentin-positive CTCs showed changes associated with the chemotherapy response.