Detection of circulating tumor cells during follow-up of patients with early breast cancer: Clinical utility for monitoring of therapy efficacy.

INTRODUCTION: Circulating tumor cells (CTCs) detection prior to and during therapy is considered as an independent and strong prognostic marker. The present study was designed to isolate and characterize CTCs in peripheral blood of an early breast cancer (BC) patient as a biomarker for monitoring treatments efficacy. MATERIALS AND METHODS: In total, 54 early breast cancer patients undergoing neoadjuvant and/or adjuvant chemotherapy regimens were enrolled into a prospective study. CTC detection in blood was performed by AdnaTest BreastCancer(™) (AdnaGen AG, Germany), which is based on the detection of EpCAM, HER2 and MUC1 specific transcripts in enriched CTC-lysates. Additionally, cDNA from isolated CTCs and PBMC was used for qPCR gene expression analysis of TOP1, TOP2A, CTSD, ST6, CK19 and reference gene actin. RESULTS: We found that CTCs can be detected in the peripheral blood of approximately 31% of early stage breast cancer patients. The presence of CTCs was detected in 36% ER positive, 32% PR positive and 30% HER2 positive patients. We found no correlation between CTCs and tumor size, tumor grade, histological grade and receptor status. Only 7% of all patients remained CTCs positive after adjuvant therapy. Gene expression analysis revealed a particular heterogeneity of the studied genes. CONCLUSIONS: In conclusion, CTC detection may be a promising early marker of disease progression potentially enhancing the difficult therapeutic decisions. Further studies should, however, clearly demonstrate its utility for both the prediction of outcome and monitoring the effect of treatment.

[Circulating tumor cells and prostate cancer prognosis]. / Cirkulující nádorové bunky a prognóza karcinomu prostaty.

Prostate cancer (PC) is the most common malignant disease in men. Prognosis of patients with metastatic PC is generally unfavourable; however there are significant differences in survival at this stage of the disease. The definition of prognosis is essential for the selection of therapy, respecting an individual risk. In recent years, the association between circulating tumor cells (CTC) detection and response to PC treatment has been widely investigated. Detection of CTC is based on a metastatic process theory and uses well-known tumor-specific antigens on the cell surface. Individual methods assess CTC with different sensitivity and are not yet efficient at the localised PC stage. Only the method of immunomagnetic separation and semi-automatic visualisation (CellSearchTM) has been validated and approved for the use in the PC management. Assessment of the CTC count directly correlates with the prognosis of patients with castration-resistant PC. Change in the CTC count during the therapy also considerably improves risk estimation and represents a marker of overall survival. New methods of CTC cultivation and gene profiling may contribute to individualisation of the treatment similarly to breast cancer. The authors present a review article about theory, methods of detection and clinical use of CTC in castration-resistant PC.

Immunophenotyping of peripheral blood in NSCLC patients discriminates responders to immune checkpoint inhibitors.

PURPOSE: Immune checkpoint inhibitors (ICIs) dramatically changed the prognosis of patients with NSCLC. Unfortunately, a reliable predictive biomarker is still missing. Commonly used biomarkers, such as PD-L1, MSI, or TMB, are not quite accurate in predicting ICI efficacy. METHODS: In this prospective observational cohort study, we investigated the predictive role of erythrocytes, thrombocytes, innate and adaptive immune cells, complement proteins (C3, C4), and cytokines from peripheral blood of 224 patients with stage III/IV NSCLC treated with ICI alone (pembrolizumab, nivolumab, and atezolizumab) or in combination (nivolumab + ipilimumab) with chemotherapy. These values were analyzed for associations with the response to the treatment and survival endpoints. RESULTS: Higher baseline Tregs, MPV, hemoglobin, and lower monocyte levels were associated with favorable PFS and OS. Moreover, increased baseline basophils and lower levels of C3 predicted significantly improved PFS. The levels of the baseline immature granulocytes, C3, and monocytes were significantly associated with the occurrence of partial regression at the first restaging. Multiple studied parameters (n = 9) were related to PFS benefit at the time of first restaging as compared to baseline values. In addition, PFS nonbenefit group showed a decrease in lymphocyte count after three months of therapy. The OS benefit was associated with higher levels of lymphocytes, erythrocytes, hemoglobin, MCV, and MPV, and a lower value of NLR after three months of treatment. CONCLUSION: Our work suggests that parameters from peripheral venous blood may be potential biomarkers in NSCLC patients on ICI. The baseline values of Tregs, C3, monocytes, and MPV are especially recommended for further investigation.

Immunity following SARS-CoV-2 vaccination in autoimmune neurological disorders treated with rituximab or ocrelizumab.

Background: Rituximab (RTX) and ocrelizumab (OCR), B cell-depleting therapy targeting CD20 molecules, affect the humoral immune response after vaccination. How these therapies influence T-cell-mediated immune response against SARS-CoV-2 after immunization remains unclear. We aimed to evaluate the humoral and cellular immune response to the COVID-19 vaccine in a cohort of patients with multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and myasthenia gravis (MG). Methods: Patients with MS (83), NMOSD (19), or MG (7) undergoing RTX (n=47) or OCR (n=62) treatment were vaccinated twice with the mRNA BNT162b2 vaccine. Antibodies were quantified using the SARS-CoV-2 IgG chemiluminescence immunoassay, targeting the spike protein. SARS-CoV-2-specific T cell responses were quantified by interferon γ release assays (IGRA). The responses were evaluated at two different time points (4-8 weeks and 16-20 weeks following the 2nd dose of the vaccine). Immunocompetent vaccinated individuals (n=41) were included as controls. Results: Almost all immunocompetent controls developed antibodies against the SARS-CoV-2 trimeric spike protein, but only 34.09% of the patients, without a COVID-19 history and undergoing anti-CD20 treatment (via RTX or OCR), seroconverted. This antibody response was higher in patients with intervals of longer than 3 weeks between vaccinations. The duration of therapy was significantly shorter in seroconverted patients (median 24 months), than in the non-seroconverted group. There was no correlation between circulating B cells and the levels of antibodies. Even patients with a low proportion of circulating CD19+ B cells (<1%, 71 patients) had detectable SARS-CoV-2 specific antibody responses. SARS-CoV-2 specific T cell response measured by released interferon γ was detected in 94.39% of the patients, independently of a humoral immune response. Conclusion: The majority of MS, MG, and NMOSD patients developed a SARS-CoV-2-specific T cell response. The data suggest that vaccination can induce SARS-CoV-2-specific antibodies in a portion of anti-CD20 treated patients. The seroconversion rate was higher in OCR-treated patients compared to those on RTX. The response represented by levels of antibodies was better in individuals, with intervals of longer than 3 weeks between vaccinations.

Gene Expression Analysis of Immunomagnetically Enriched Circulating Tumor Cell Fraction in Castration-Resistant Prostate Cancer.

BACKGROUND: Molecular characterization of tumors could be a key to therapeutic decision-making with regards to targeted therapies in castration-resistant prostate cancer (CRPC). A convenient solution may be non-invasive liquid biopsy testing of circulating tumor cells (CTCs). For this reason, CTC-enriched samples obtained by immunomagnetic separation (AdnaTest®) were studied as a source material for high-throughput gene expression analysis using BioMark™. PATIENTS AND METHODS: CTC-enriched samples from 41 CRPC patients previously determined to be CTC positive using the AdnaTest® were retrospectively re-analysed for androgen receptor (AR) messenger RNA (mRNA), using the updated AdnaTest®. Blood samples were drawn two times from each patient: at the time of CRPC diagnosis and after the third docetaxel cycle. A gene expression panel of 27 genes related to CRPC therapeutic decision-making, including AR full length (ARFL) and splice variant 7 (ARV7), was retrospectively analyzed on a BioMark™ platform in 29 of 41 patients. RESULTS: The AdnaTest® detected AR mRNA in three-quarters of CTC-positive samples taken at the time of CRPC diagnosis and after the third docetaxel cycle. AR detection was associated with a shorter disease-specific survival (45.0 vs. 20.4 months) at the time of CRPC diagnosis. ARFL expression at the time of CRPC diagnosis, measured on the BioMark™ platform, was associated with a lower decrease of serum level of prostate-specific antigen (sPSA) (p = 0.029), i.e., worse therapy response. ARV7 was found in 38% of the ARFL--positive samples at both analyzed timepoints. CONCLUSION: Detection of AR expression by AdnaTest® in CTC-enriched samples may help predict patients' survival. These AdnaTest® CTC-enriched samples can be used in a high-throughput quantitative polymerase chain reaction (qPCR) analysis of gene expression, provided that the specificity of the assay for each individual gene is properly validated. The BioMark™ platform can be used for the simultaneous detection of ARFL and ARV7 and other genes in CTC-enriched samples from CRPC patients.

Circulating tumor cells and serum levels of MMP-2, MMP-9 and VEGF as markers of the metastatic process in patients with high risk of metastatic progression.

BACKGROUND AND AIMS: Metastases are a severe complication in cancer patients and biomarkers predicting their progression are still lacking for specific groups of patients. HER2 positive breast cancer (HER2 BC) patients on trastuzumab therapy are at risk of the development of unpredictable and often fatal central nervous system (CNS) metastases and castration resistant prostate cancer (CRPC) patients urgently need a marker of disease progression during therapy. Proposed metastatic markers: circulating tumor cells (CTC), serum levels of matrix metalloproteinase 2 (MMP-2), 9 (MMP-9) and vascular endothelial growth factor (VEGF) were prospectively studied to confirm their utility in these two narrowly defined groups of cancer patients. PATIENTS AND METHODS: The groups comprised 44 advanced HER2 BC, 24 CRPC patients and 42 healthy controls. An immunomagnetic separation method followed by PCR and electrophoretic detection (AdnaGen, Germany) were used for CTC determination. Serum marker levels were determined by the ELISAs (R&D System, USA). RESULTS: MMP-2 serum level was significantly higher in HER2 BC patients who developed CNS metastases, especially if there were also bone metastases. CTCs were a negative predictive marker for overall survival in HER2 BC patients. MMP-9 serum level was significantly higher in CRPC patients in whom disease progression occurred. CTC vanished from the blood of most of the CRPC patients (from 88% to 37%) during chemotherapy. CONCLUSION: MMP-2 serum level and CTCs show the potential to predict CNS metastases and overall survival in BC patients. CTCs and MMP-9 serum level could be a promising therapy response marker in CRPC patients.

The characterization of four gene expression analysis in circulating tumor cells made by Multiplex-PCR from the AdnaTest kit on the lab-on-a-chip Agilent DNA 1000 platform.

INTRODUCTION: Nowadays, on-a-chip capillary electrophoresis is a routine method for the detection of PCR fragments. The Agilent 2100 Bioanalyzer was one of the first commercial devices in this field. Our project was designed to study the characteristics of Agilent DNA 1000 kit in PCR fragment analysis as a part of circulating tumour cell (CTC) detection technique. Despite the common use of this kit a complex analysis of the results from a long-term project is still missing. MATERIALS AND METHODS: A commercially available Agilent DNA 1000 kit was used as a final step in the CTC detection (AdnaTest) for the determination of the presence of PCR fragments generated by Multiplex PCR. Data from 30 prostate cancer patients obtained during two years of research were analyzed to determine the trueness and precision of the PCR fragment size determination. Additional experiments were performed to demonstrate the precision (repeatability, reproducibility) and robustness of PCR fragment concentration determination. RESULTS: The trueness and precision of the size determination was below 3% and 2% respectively. The repeatability of the concentration determination was below 15%. The difference in concentration determination increases when Multiplex-PCR/storage step is added between the two measurements of one sample. CONCLUSIONS: The characteristics established in our study are in concordance with the manufacturer's specifications established for a ladder as a sample. However, the concentration determination may vary depending on chip preparation, sample storage and concentration. The 15% variation of concentration determination repeatability was shown to be partly proportional and can be suppressed by proper normalization.

Prognosis of Castration-resistant Prostate Cancer Patients - Use of the AdnaTest® System for Detection of Circulating Tumor Cells.

BACKGROUND: Detection of circulating tumor cells (CTC) in patients with castration-resistant prostate cancer (CRPC) may improve the estimate of chemotherapy response. We evaluated the AdnaTest® system in patients receiving docetaxel. PATIENTS AND METHODS: CTC analysis was carried out in 37 patients by immunomagnetic separation. Correlation between serum prostate-specific antigen (sPSA) change and CTC presence and the influence of each parameter on the overall survival (OS) were evaluated. RESULTS: We detected CTCs in 32 and 16 patients before and after three docetaxel cycles, respectively. The sPSA level correlated with CTC positivity during docetaxel therapy (p=0.0031). The longest OS was in patients negative for CTCs in both samples (p=0.0228). Change in sPSA levels was associated with treatment response (p=0.033). CONCLUSION: We detected CTCs in a considerable number of patients with CRPC. The absolute change of sPSA level correlated with OS. CTC presence during docetaxel therapy was associated with shorter OS.

Circulating tumor cells in patients with breast cancer: monitoring chemotherapy success.

UNLABELLED: Circulating tumor cells (CTCs) are an independent prognostic factor for patients with metastatic breast cancer (MBC). However, the role of CTCs in early breast cancer management is not yet clearly defined. The aim of this study was to assess the CTC-positivity rate in patients undergoing chemotherapy depending on breast cancer stage in the adjuvant and neoadjuvant setting. We evaluated the ability to confirm therapy response by CTC analysis. PATIENTS AND METHODS: CTCs isolated from blood by means of immunomagnetic separation were further characterized by means of reverse transcriptase - polymerase chain reaction (RT-PCR) for epithelial cell adhesion molecule (EPCAM), mucin 1 (MUC1) and v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 2 (HER2) transcripts with the AdnaTest™. This prospective study included 179 patients; altogether 419 blood samples were evaluated. Patients with primary tumors were divided into neoadjuvant (n=38), and adjuvant (n=100) groups. Forty-one patients with MBC were evaluated under palliative treatment. RESULTS: CTC positivity was described in 35% of patients with early breast cancer without detected metastases before neoadjuvant chemotherapy; similarly, a 26% positivity rate was found in the adjuvant group. In patients with MBC, we detected CTCs in 43% of them. After completing the therapy, the CTC positivity rate decreased to 5% in the neoadjuvant group, to 13% in the adjuvant group and to 12% in the MBC group. CTC positivity after the therapy may classify a subgroup of patients at high risk of developing metastatic disease. This was even true when a patient was evaluated as being CTC-negative before chemotherapy. The multivariate analysis evaluating the correlation of CTC positivity with clinicopathological characteristics such as tumor size, nodal involvement, hormone receptor status, HER2 expression and number of metastatic sites revealed no statistically significant relationships. CONCLUSION: CTC status may have a significant impact on early BC management.