Detection Of Tumor Cells Research Articles

Clinical application of circulating tumor cell detection: the challenges and solutions

循环肿瘤细胞（circulating tumor cells，CTC）是肿瘤发生远处转移的关键环节，也是肿瘤液体活检的主要材料之一，在肿瘤患者的预后判断、疗效预测、疗效评价以及复发转移和耐药机制的研究中都具有重要的临床意义。然而，由于CTC的稀有性、异质性以及转移过程的复杂性等原因，CTC检测的临床应用仍然面临诸多挑战，需要采取行之有效的应对策略予以解决。本文对上述内容进行了综述。.

Novel measurement technique to detect breast tumor based on the smallest form factor of UWB patch antenna

AbstractA small ultra-wideband (UWB) patch antenna for microwave breast imaging (MWI) applications is shown off in this paper. However, to improve the antenna performance relating to the bandwidth (BW), the radiating element of the suggested antenna is modified by adding slits in the patch as well as the ground plane. The proposed prototype has a relatively small size of 20 × 19 × 1.6 mm3and it accomplishes a return loss below −10 dB (S11< −10 dB) at an overall BW of 7 GHz (4–11 GHz) with more than 3 dBi realized gain. The antenna is designed and simulated by using a finite integration technique-based simulator. In this way, the characteristics of the fabricated antenna are measured to examine the antenna performance. Indeed, the fidelity factor of face-to-face (FtF) and side-by-side (SbS) scenarios are also noticed for the same frequency range. In the final analysis, a simulation model of the antennas, that operate as a transceiver, and a breast phantom model with tumor sample is proposed for detecting cancerous tumor cells within the breast. Hence, the proposed approach is suitable for UWB based MWI applications in tumor cell detection.

Diagnostic Value of Ascitic Tumor Markers for Gastric Cancer-associated Malignant Ascites

Background/Aims: Peritoneal carcinomatosis with malignant ascites is common in patients with advanced gastric cancer (GC). The detection of tumor cells is the gold standard for the diagnosis of malignant ascites; however, it often requires complementary tests because of its low sensitivity. Herein, we measured the levels of tumor markers in the malignant ascites of GC patients (GC-ascites) and benign ascites of liver cirrhosis patients (LC-ascites) to elucidate the diagnostic value of tumor markers in GC-ascites.Materials and Methods: The levels of CEA, cancer antigen 72-4 (CA 72-4), CA 19-9, and CA 125 were measured in 138 GC-ascites and 64 LC-ascites samples obtained from the National Biobank of Korea. We performed receiver operating characteristic curve analysis to determine the optimal cutoff value for each tumor marker.Results: CEA, CA 72-4, and CA 19-9 levels were significantly higher in GC-ascites than in LC-ascites. There was no difference in tumor marker levels between GC-ascites samples irrespective of cytology. CEA, CA 72-4, and CA 19-9 had sensitivities of 85.5%, 79.0%, and 61.6%, respectively, and specificities of 96.8%, 100.0%, and 89.1%, respectively, for distinguishing GC-ascites samples from LC-ascites samples. The diagnostic accuracy was improved by combining two or more tumor markers. The combination of CEA and CA 72-4 showed the highest sensitivity (86.2%) and specificity (100%).Conclusions: Measurement of tumor markers, such as CEA, CA 72-4, and CA 19-9, in ascites samples could help diagnose GC-ascites, and combining two or more tumor markers could further increase the diagnostic yield, even in cytology-negative patients.

Gene signatures of circulating breast cancer cell models are a source of novel molecular determinants of metastasis and improve circulating tumor cell detection in patients

BackgroundProgression to stage IV disease remains the main cause of breast cancer-related deaths. Increasing knowledge on the hematogenous phase of metastasis is key for exploiting the entire window of opportunity to interfere with early dissemination and to achieve a more effective disease control. Recent evidence suggests that circulating tumor cells (CTCs) possess diverse adaptive mechanisms to survive in blood and eventually metastasize, encouraging research into CTC-directed therapies.MethodsOn the hypothesis that the distinguishing molecular features of CTCs reveal useful information on metastasis biology and disease outcome, we compared the transcriptome of CTCs, primary tumors, lymph-node and lung metastases of the MDA-MB-231 xenograft model, and assessed the biological role of a panel of selected genes, by in vitro and in vivo functional assays, and their clinical significance in M0 and M+ breast cancer patients.ResultsWe found that hematogenous dissemination is governed by a transcriptional program and identified a CTC signature that includes 192 up-regulated genes, mainly related to cell plasticity and adaptation, and 282 down-regulated genes, involved in chromatin remodeling and transcription. Among genes up-regulated in CTCs, FADS3 was found to increases cell membrane fluidity and promote hematogenous diffusion and lung metastasis formation. TFF3 was observed to be associated with a subset of CTCs with epithelial-like features in the experimental model and in a cohort of 44 breast cancer patients, and to play a role in cell migration, invasion and blood-borne dissemination. The analysis of clinical samples with a panel of CTC-specific genes (ADPRHL1, ELF3, FCF1, TFF1 and TFF3) considerably improved CTC detection as compared with epithelial and tumor-associated markers both in M0 and stage IV patients, and CTC kinetics informed disease relapse in the neoadjuvant setting.ConclusionsOur findings provide evidence on the potential of a CTC-specific molecular profile as source of metastasis-relevant genes in breast cancer experimental models and in patients. Thanks to transcriptome analysis we generated a novel CTC signature in the MDA-MB-231 xenograft model, adding a new piece to the current knowledge on the key players that orchestrate tumor cell hematogenous dissemination and breast cancer metastasis, and expanding the list of CTC-related biomarkers for future validation studies.

PRIMERA trial (NCT04188275), early survival results from a prospective trial exploring impact of circulating tumor cell detection in castrate resistant prostate cancer patients undergoing abiraterone or enzalutamide I line treatment.

137 Background: Circulating tumor cells (CTC) detection and androgen receptor splice variant 7 (ARV7) expression have been shown to be associated with worse clinical outcomes in metastatic castration resistant prostate cancer (mCRPC) patients undergoing androgen receptor targeted agents (ARTA) treatment, paving the way for alternative treatment options for patients with negative predictive factors. Full-length androgen receptor (ARFL), prostate specific membrane antigen and prostate specific antigen (PSA) may further help to refine prognostic models. In our institution, a prospective observational trial testing CTC detection in mCRPC undergoing ARTA treatment (PRIMERA trial, NCT04188275) terminated the planned enrollment in 2020. Here we present early results of the overall cohort. Methods: PRIMERA (NCT04188275) is a prospective, observational trial enrolling mCRPC patients undergoing ARTA treatment. All patients were treated with either abiraterone or enzalutamide in I line setting. Blood samples to detect CTCs were taken before starting ARTA treatment. Reverse transcription - quantitative real-time PCR (RT-qPCR) was used to determine the CTC expression of PSA, PSMA, AR and ARV7. PSA drop (defined as difference between baseline PSA at ARTA treatment start and PSA at nadir under treatment), progression free and overall survival (PFS and OS) and their correlation with CTC detection were reported. Explorative analysis about AR, PSA and PSMA expression in CTC+ patients were conducted. Results: Overall, 44 patients were included. CTC were detected at treatment start in 19 patients (43,2%), of whom 3(15,78%), 9(63,15%), 15(78,94%) and 14 (73.68%) patients expressed ARV7, ARFL, PSA and PSMA, respectively. Biochemical response was significantly improved in CTC+ vs. CTC- patients, with median PSA drop values of 18.5 vs 2.5 ng/ml (p=0.03). After a median follow up of 18 months, 22 (50%) patients progressed. PFS was significantly longer in CTC- patients (not reached vs 16 months, respectively, p=0.02). Eight (18.2%) patients died, a non-significant trend in terms of overall survival was detected in favor of CTC- patients (not reached vs 29 months, respectively, p=0.05). AR, PSA and PSMA expression in CTC+ had no significant impact on PSA drop, PFS or OS. Conclusions: PRIMERA trial confirmed the CTC detection predictive importance in mCRPC patients. Adequately powered studies will be needed to further explore CTC profiling in this setting. Clinical trial information: NCT04188275.

Abstract P2-01-12: Detection of circulating tumor cells in cerebrospinal fluid for patients with suspected breast cancer leptomeningeal metastases: A prospective study

Abstract Background Breast cancer (BC) is the most frequent cause of leptomeningeal metastases (LM). LM diagnosis is confirmed by the detection of tumor cells in the cerebrospinal fluid (CSF) using conventional cytology (gold standard). However, even with optimal CSF sample volume and time to the analysis, the sensitivity of this technique is low, demanding repeated samples. Here, we aimed to evaluate the value of circulating tumor cell (CTC) detection in CSF using the CellSearch® system for LM diagnosis. Materials and Methods This prospective, monocentric study included adult BC patients with suspected LM (clinical and/or radiological signs). CSF samples from 1-3 lumbar puncture(s) were analyzed: protein level, conventional cytology (60 drops), and CTC detection with the CellSearch® system (60 drops, first lumbar puncture only). Sensitivity (Se) and specificity (Sp) were calculated, using the results of the conventional cytology as the gold-standard. Results Forty-nine eligible patients were included (Jan 2017-Jan 2020): median age 51.8, 95.9% women, 20.4% HER2+ BC, 93.8% previously diagnosed with metastatic BC, 89.8% with clinical symptoms. Among them, 40 were evaluable (CTC detection failure: n=8, eligibility criteria failure: n=1). Median sample volume was 3.0 mL for conventional cytology samples (median time to analysis: 22min) and 3.3 mL for CTC samples. Of the 40 evaluable patients, 18 had a positive cytology (on CSF sample n=°1/n°2: n=16/n=2) and were therefore diagnosed with LM using the gold-standard method. Protein level was elevated in 88.2% of these patients, compared with 45.1% of patients with negative CSF cytology (p=0.005). CTCs were detected in these 18 patients (median 5824 CTCs, range 93-45052). CTCs were also detected in 5/22 patients with a negative cytology (median 2 CTCs, range 1-44). Among them, one patient (44 CTCs) was diagnosed with a cytologically-proven LM 9 months later, while there was no further argument for LM in the other 4 patients’ history (1-3 CTC), who died of the extra-cerebral disease after a median time of 5.2 months (range 0.9-25.9). The detection of at least one CTC in CSF was associated with a Se of 100.0% (IC95% 82.4-100) and a Spe of 77.3% (IC95% 64.3-90.3) for the diagnosis of LM. Considering the number of CTC as a quantitative value, we determined the cut-off maximizing the Youden index using the ROC analysis (93 CTC). The detection of at least 93 CTC in CSF was associated with a Se and a Spe of 100.0% for the diagnosis of LM (area under the curve [AUC]: 1.0). Conclusion CTCs were detected with the CellSearch® system in all patients diagnosed with a cytologically-proven LM, as well as in a few patients without a cytological confirmation of LM. The prognosis of these patients with CSF cytology-/CTCs+ needs to be further investigated in a larger cohort. Citation Format: Amélie Darlix, Stéphane Pouderoux, Simon Thezenas, Alexis Bievelez, William Jacot, Laure Cayrefourcq, Nicolas Menjot-de-Champfleur, Cristina Leaha, Catherine Alix-Panabières. Detection of circulating tumor cells in cerebrospinal fluid for patients with suspected breast cancer leptomeningeal metastases: A prospective study [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-01-12.

Automatic detection metastasis in breast histopathological images based on ensemble learning and color adjustment

Breast cancer is a common neoplasm among women. The cure of the disease depends on early identification and treatment of the tumor to avoid advanced stages such as metastasis of the initial lesion. Recently, studies have shown that computational methods could help specialists in this process and even provide advantages over the traditional analysis method. Thus, this work proposes a tumor cell detection method based on an ensemble of convolutional neural networks (CNN) trained with normalized images using different color adjustment techniques. Analyses of eight different color spaces and their channels, and two color normalization methods were performed to reduce the effects caused by color variation of histopathological images on the generalization of predictive models. The proposed approach evaluated six CNN architectures with color adjustment methods to define which ones improve and preserve important characteristics for the classification task. The ensemble that constitutes the proposed method comprises three models of the VGG-19 architecture trained in images generated through from the color space HSV, from the color channel RED of the RGB images, and RGB images normalized with Reinhard method, respectively. This approach was evaluated using a public image database containing 327,680 histopathological images extracted from breast tissue. The method achieved promising results, with an accuracy of 0.9193 and an AUC of 0.9772. These results demonstrate that a combination of color adjustment techniques produces better results than applying the techniques individually.

Epithelial cell adhesion molecule (EpCAM) binding short peptides derived from antibody MOC-31; De-novo design, synthesis and their in-vitro evaluation

Epithelial cell adhesion molecule (EpCAM) is one of the critical bio-maker for circulating tumor cells (CTC) detection. For capturing CTC, antibody-antigen-based techniques have mainly been explored. However, the expensiveness and tedious manufacturing process have posed certain limitations for antibody-based techniques for its wide applications in cell capturing. On the other hand, peptides are inexpensive bimolecular probes with high specificity and tunability. Although there are few reports on EpCAM binding peptides are available in literature, those peptides were selected through random library screening. Interestingly, de-novo design of the peptides against EpCAM has not been reported till date. For the first time, we have developed a small peptide (Pep14) from the complementary derived region (CDRs) of antibody MOC31 through systematic virtual screening. Selected peptide has demonstrated good binding affinity towards EpCAM with dissociation constant (Kd) of 870 nM and found to be co-localized with the anti-EpCAM antibody in EpCAM expressing cancer cells (MCF-7). Therefore, the short peptide Pep14 hold promise for capturing circulatory tumor cells through EpCAM binding.

Determining programmed cell death ligand 1 expression in circulating tumor cells of patients with clear cell renal cell carcinoma and its correlation with response to programmed cell death protein 1 inhibitors.

There is a great interest in determining whether the expression of the programmed cell death ligand 1 is correlated with the efficacy of immune checkpoint inhibitors in patients with clear cell renal cell carcinoma; however, primary tumor biopsies can only provide limited information. Therefore, we explored the expression of programmed cell death ligand 1 on circulating tumor cells, which is a potential predictor of therapeutic response. Circulating tumor cells were isolated from 20 clear cell renal cell carcinoma patients based on cell surface markers targeting clear cell renal cell carcinoma using IsoFlux device, followed by identification according to cell morphology and immunofluorescence studies. Programmed cell death ligand 1 expression status and clinical correlations were also analyzed. Before treatment with programmed cell death protein 1 inhibitors, circulating tumor cells were detected in all patients, ranging from 1 to 22 (median 7), with 75% (15/20) of the patients having programmed cell death ligand 1 + circulating tumor cells. Circulating tumor cell programmed cell death ligand 1 expression did not correlate with the immunohistochemical staining of programmed cell death ligand 1 in primary tumors. During treatment with programmed cell death protein 1 inhibitors, the disease control rate was much higher in the patients harboring programmed cell death ligand 1 + circulating tumor cells (73%, 11/15) than others (20%, 1/5). We also found that changes in total circulating tumor cell numbers and programmed cell death ligand 1 + circulating tumor cell counts correlated well with the disease outcome. We showed that the presence of programmed cell death ligand 1 + circulating tumor cells before programmed cell death protein 1 inhibition treatment could be a prognosis predictive factor and that the dynamic changes in circulating tumor cell numbers may be used to monitor the therapeutic response. Our study confirms the possibility of programmed cell death ligand 1 + circulating tumor cell detection in clear cell renal cell carcinoma patients' blood samples, which can potentially be used as an individualized immunotherapy molecular biomarker for real-time exploration.

Selective Accumulation to Tumor Cells with Coacervate Droplets Formed from a Water-Insoluble Acrylate Polymer.

Selective targeting of specific cells without the use of biological ligands has not been achieved. In the present study, we revealed that the coacervate droplets formed from poly(2-methoxyethyl acrylate) (PMEA) and its derivatives selectively accumulated to tumor cells. PMEA derivatives, which are insoluble acrylate polymers, induced coacervation in water to form polymer-dense droplets via hydrophobic interaction. Interestingly, the accumulation of coacervate droplets to tumor cells was involved in the bound water content of PMEA derivatives. Coacervate droplets with a high bound water content accumulated and internalized up to 36.6-fold higher in HeLa cervical tumor cells than in normal human fibroblasts (NHDF). Moreover, the interactions between coacervate droplets and plasma membrane components such as CD44 played a key role in this accumulation process. Therefore, coacervate droplets formed from PMEA derivatives have great clinical potential in tumor cell detection, development of alternative tumor-targeting ligands, and optimization of drug delivery carriers.

Cyclooxygenase 2 Effector Genes as Potential Inflammation-Related Biomarkers for Colorectal Cancer Circulating Tumor Cells Detection by Liquid Biopsy.

Cyclooxygenase 2 (COX2) has been implicated in cancer development and metastasis. We have identified several COX2-regulated inflammation-related genes in human colorectal cancer cells and shown that some of them play important roles in tumor progression. In this work, we have studied the COX2-regulated genes in the mouse colorectal cancer cell line CT26, to find that many are also regulated by COX2 over-expression. On the other hand, we generated a CT26 cell line expressing Gfp and Luciferase, to study tumor growth and metastasis in immunocompetent Balb/c mice. We then collected solid tissue, and blood samples, from healthy and tumor-bearing mice. Using the Parsortix® cell separation system and taking advantage of the fact that the tumor cells expressed Gfp, we were able to identify circulating tumor cells (CTCs) in some of the mice. We compared the mRNA expression levels of Ptgs2 and effector genes in the samples obtained from tumor-bearing or healthy mice, namely, tumor or healthy colon, Ficoll purified buffy coat, and Parsortix-isolated cells to find different patterns between healthy, tumor-bearing mice with or without CTCs. Although for genes like Il15 we did not observe any difference between healthy and tumor-bearing mice in Ficoll or Parsortix samples; others, such as Egr1, Zc3h12a, Klf4, or Nfat5, allowed distinguishing for cancer or CTC presence. Gene expression analysis in Ficoll or Parsortix processed samples, after liquid biopsy, may offer valuable diagnostic and prognostic information and thus should be further studied.

The detection of tumor cells in the unchanged parenchyma — is a reliable sign of the spread of lung cancer

The detection of tumor cells in the unchanged parenchyma — is a reliable sign of the spread of lung cancer

Characterization and detection of Circulatory Tumor Cells (CTCs) using imaging flow cytometry in liver cirrhosis and Hepatocellular carcinoma patients

Background and aim: Hepatocellular carcinoma (HCC) is asymptomatic at an early stage which delays its timely diagnosis and treatment. Circulating tumor cells (CTCs), derived from a primary or secondary tumor, may help in the management of HCC. Here, we evaluate and characterize CTCs in HCC and liver cirrhosis (LC) patients.

Recent advances in micro-/nanostructure array integrated microfluidic devices for efficient separation of circulating tumor cells.

Circulating tumor cells (CTCs) released from the primary tumor to peripheral blood are promising targets for liquid biopsies. Their biological information is vital for early cancer detection, efficacy assessment, and prognostic monitoring. Despite the tremendous clinical applications of CTCs, development of effective separation techniques are still demanding. Traditional separation methods usually use batch processing for enrichment, which inevitably destroy cell integrity and affect the complete information acquisition. Considering the rarity and heterogeneity of CTCs, it is urgent to develop effective separation methods. Microfluidic chips with precise fluid control at the micron level are promising devices for CTC separation. Their further combination with micro-/nanostructure arrays adds more biomolecule binding sites and exhibit unique fluid barrier effect, which significantly improve the CTC capture efficiency, purity, and sensitivity. This review summarized the recent advances in micro-/nanostructure array integrated microfluidic devices for CTC separation, including microrods, nanowires, and 3D micro-/nanostructures. The mechanisms by which these structures contribute to improved capture efficiency are discussed. Two major categories of separation methods, based on the physical and biological properties of CTCs, are discussed separately. Physical separation includes the design and preparation of micro-/nanostructure arrays, while chemical separation additionally involves the selection and modification of specific capture probes. These emerging technologies are expected to become powerful tools for disease diagnosis in the future.

Laboratory-Scale Production of Sterile Targeted Microbubbles.

Perfluorocarbon gas-filled microbubbles are clinically used as ultrasound contrast agents. We have been developing targeted microbubbles based BACS (buoyancy activated cell sorting) or BUBLES (buoyancy enabled separation) for ex vivo cell isolation from bloods for circulating tumor cell (CTC) detection and hematopoietic cell isolation. Recently, we further applied targeted microbubbles for multimarker cell sorting, and as artificial antigen presenting cells (aAPC) for T cell activation and expansion by taking advantage of a number of interesting properties of lipid-shelled microbubbles. This chapter will describe the process of manufacturing sterile targeted microbubbles for research applications.

DNA Walker Induced “Signal Off” Electrochemical Cytosensor Strategy for Ultrasensitive Detection of Tumor Cells

DNA Walker Induced “Signal Off” Electrochemical Cytosensor Strategy for Ultrasensitive Detection of Tumor Cells

THE ROLE OF SPERM SEDIMENT CYTOLOGY IN NON-INVASIVE DIAGNOSTICS OF SEMINOMA. CASE REPORT

Testicular neoplasms cause diagnostic difficulties for clinical and laboratory diagnostics in young and middle-aged men. Seminoma refers to germ-cell tumors (GCTs) and is the most common cancer of this localization. But the timely and correct diagnostics by non-invasive technologies is still difficult. The clinical case clarifies the innovative techniques by Sperm. Sediment Cytology (SSC) as the non-invasive diagnostic approach resulting in excellent tumor cells detection. While a non-invasive conventional diagnostics and laboratory examination are of low diagnostic value this method can help oncologists and urologists for a confident judgment about the nature of the process and the timely choice of further treatment tactics.

Determination of EGFR-overexpressing tumor cells by magnetic gold-decorated graphene oxide nanocomposites based impedance sensor

This work developed an electrochemical impedance spectroscopy (EIS) sensor for detection of EGFR (epidermal growth factor receptor)-overexpressing tumor cell and preliminary estimation of EGFR expression. Here, EGFR antibodies as the specific antibodies for cancer cells were conjugated on magnetic gold-decorated graphene oxide nanocomposites, which were used to capture the EGFR-overexpressing tumor cells. The magnetically responsive tumor cells were enriched and immobilized on a magnetic glassy carbon electrode (mGCE) surface, leading to increased electron-transfer resistance (Ret) utilized for determination of cells and preliminary evaluation of EGFR expression level. This strategy enables the enrichment, fixation and detection of tumor cells to be accomplished in a facile way. An excellent linearity in the range of 2.0 × 102 − 3.0 × 105 cell mL−1 with the detection limit of 152 cell mL−1 for MDA-MB-231 cells was obtained. Investigation on the expression levels of EGFR on various types of cells was conducted. MDA-MB-231 cells showed a distinctly higher EGFR expression, compared with MHCC97-L and L02 cells, providing the possibility for the EGFR-targeted therapy of the tumors. It is expected that the proposed sensor has the potential to be applied for cancer monitoring.

Modified 16-Quasi Log Periodic Antenna Array for Microwave Imaging of Breast Cancer Detection

In this paper, an effective system for microwave imaging of breast tumor detection using modified 16-planar log periodic antenna (PLPA) array is presented. The modified PLPA operates in the band from 2 to 5 GHz with stable directional patterns in the end-fire direction. Once the results of a single antenna element have been validated, the design is extended to include 16 antenna elements. All 16 transceiver antennas are vertically placed around the phantom in a circular manner where one antenna acts as a transmitter and the rest work as receivers. Delay and Sum (DAS) algorithm is used for post processing the acquired scattered signals from the sensors to reconstruct the image of the breast and to identify the existence of breast tumors. The electromagnetic simulators CST and HFSS are used to design the system, while MATLAB is used to process the data. The developed PLPA array-based microwave imaging system performs admirably, making it one of the most effective systems for detecting tumor cells.

Quantification of gold nanoparticles using total reflection X-ray fluorescence by Monte Carlo simulation (MCNP code) applied to cancer cell research

Detection and quantification of gold nanoparticles (AuNPs) using total reflection X-rays fluorescence (TXRF) technique is carried out by Monte Carlo simulation (MCNP code, version 6.2). Aiming at applications to cancer cell research, parameters of 50 nm and 100 nm AuNPs from certified solutions were used in the simulations. Two different procedures of sample preparation were considered, one using acid digestion and other without any pre-treatment of AuNPs. For acid digested AuNPs, spectra of five samples with different Au masses (from ng to sub-ng), were simulated so as to obtain a calibration curve. The average detection and quantification limits using these digested samples were (31.0 ± 0.5)pg and (92.9 ± 1.4)pg, respectively. Fluorescence emitted by undigested samples containing spherical 50 nm and 100 nm were also simulated and nanoparticle aggregation was modelled. It is shown that for complete clustering, the intensity of the fluorescence emitted by 50 nm and 100 nm AuNPs drop to 45.82% and 32.29%, respectively, compared to the undigested cases with the same Au mass. For stable colloidal samples of AuNPs, the signal depends on the Au mass only, being statistically the same as the acid digested cases. Our results extend recent studies in TXRF spectroscopy as a tool to quantify the uptake of AuNPs by cancer cells. A potential novel application of TXRF to circulating tumor cell (CTC) detection is proposed.