Immunogenicity and reactogenicity of BNT162b2 booster in ChAdOx1-S-primed participants (CombiVacS): a multicentre, open-label, randomised, controlled, phase 2 trial.

BACKGROUND: To date, no immunological data on COVID-19 heterologous vaccination schedules in humans have been reported. We assessed the immunogenicity and reactogenicity of BNT162b2 (Comirnaty, BioNTech, Mainz, Germany) administered as second dose in participants primed with ChAdOx1-S (Vaxzevria, AstraZeneca, Oxford, UK). METHODS: We did a phase 2, open-label, randomised, controlled trial on adults aged 18-60 years, vaccinated with a single dose of ChAdOx1-S 8-12 weeks before screening, and no history of SARS-CoV-2 infection. Participants were randomly assigned (2:1) to receive either BNT162b2 (0·3 mL) via a single intramuscular injection (intervention group) or continue observation (control group). The primary outcome was 14-day immunogenicity, measured by immunoassays for SARS-CoV-2 trimeric spike protein and receptor binding domain (RBD). Antibody functionality was assessed using a pseudovirus neutralisation assay, and cellular immune response using an interferon-γ immunoassay. The safety outcome was 7-day reactogenicity, measured as solicited local and systemic adverse events. The primary analysis included all participants who received at least one dose of BNT162b2 and who had at least one efficacy evaluation after baseline. The safety analysis included all participants who received BNT162b2. This study is registered with EudraCT (2021-001978-37) and ClinicalTrials.gov (NCT04860739), and is ongoing. FINDINGS: Between April 24 and 30, 2021, 676 individuals were enrolled and randomly assigned to either the intervention group (n=450) or control group (n=226) at five university hospitals in Spain (mean age 44 years [SD 9]; 382 [57%] women and 294 [43%] men). 663 (98%) participants (n=441 intervention, n=222 control) completed the study up to day 14. In the intervention group, geometric mean titres of RBD antibodies increased from 71·46 BAU/mL (95% CI 59·84-85·33) at baseline to 7756·68 BAU/mL (7371·53-8161·96) at day 14 (p<0·0001). IgG against trimeric spike protein increased from 98·40 BAU/mL (95% CI 85·69-112·99) to 3684·87 BAU/mL (3429·87-3958·83). The interventional:control ratio was 77·69 (95% CI 59·57-101·32) for RBD protein and 36·41 (29·31-45·23) for trimeric spike protein IgG. Reactions were mild (n=1210 [68%]) or moderate (n=530 [30%]), with injection site pain (n=395 [88%]), induration (n=159 [35%]), headache (n=199 [44%]), and myalgia (n=194 [43%]) the most commonly reported adverse events. No serious adverse events were reported. INTERPRETATION: BNT162b2 given as a second dose in individuals prime vaccinated with ChAdOx1-S induced a robust immune response, with an acceptable and manageable reactogenicity profile. FUNDING: Instituto de Salud Carlos III. TRANSLATIONS: For the French and Spanish translations of the abstract see Supplementary Materials section.

Economic Analysis of the Reduction of Blood Transfusions during Surgical Procedures While Continuous Hemoglobin Monitoring Is Used.

BACKGROUND: Two million transfusions are performed in Spain every year. These come at a high economic price for the health system, increasing the morbidity and mortality rates. The way of obtaining the hemoglobin concentration value is via invasive and intermittent methods, the results of which take time to obtain. The drawbacks of this method mean that some transfusions are unnecessary. New continuous noninvasive hemoglobin measurement technology can save unnecessary transfusions. METHODS: A prospective study was carried out with a historical control of two homogeneous groups. The control group used the traditional hemoglobin measurement methodology. The experimental group used the new continuous hemoglobin measurement technology. The difference was analyzed by comparing the transfused units of the groups. The economic savings was calculated by multiplying the cost of a transfusion by the difference in units, taking into account measurement costs. RESULTS: The percentage of patients needing a transfusion decreased by 7.4%, and the number of transfused units per patient by 12.56%. Economic savings per patient were €20.59. At the national level, savings were estimated to be 13,500 transfusions (€1.736 million). CONCLUSIONS: Constant monitoring of the hemoglobin level significantly reduces the need for blood transfusions. By using this new measurement technology, health care facilities can significantly reduce costs and improve care quality.

Monocytes inhibit NK activity via TGF-ß in patients with obstructive sleep apnoea.

Obstructive sleep apnoea (OSA) is associated with cancer incidence and mortality. The contribution of the immune system appears to be crucial; however, the potential role of monocytes and natural killer (NK) cells remains unclear.Quantitative reverse transcriptase PCR, flow cytometry and in vitro assays were used to analyse the phenotype and immune response activity in 92 patients with OSA (60 recently diagnosed untreated patients and 32 patients after 6 months of treatment with continuous positive airway pressure (CPAP)) and 29 healthy volunteers (HV).We determined that monocytes in patients with OSA exhibit an immunosuppressive phenotype, including surface expression of glycoprotein-A repetitions predominant protein (GARP) and transforming growth factor-ß (TGF-ß), in contrast to those from the HV and CPAP groups. High levels of TGF-ß were detected in OSA sera. TGF-ß release by GARP+ monocytes impaired NK cytotoxicity and maturation. This altered phenotype correlated with the hypoxic severity clinical score (CT90). Reoxygenation eventually restored the altered phenotypes and cytotoxicity.This study demonstrates that GARP+ monocytes from untreated patients with OSA have an NK-suppressing role through their release of TGF-ß. Our findings show that monocyte plasticity immunomodulates NK activity in this pathology, suggesting a potential role in cancer incidence.

Veliparib in combination with whole-brain radiation therapy for patients with brain metastases from non-small cell lung cancer: results of a randomized, global, placebo-controlled study.

Veliparib is a potent, orally bioavailable, poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitor that crosses the blood-brain barrier and has been shown to potentiate the effects of radiation in preclinical and early clinical studies. This phase 2, randomized, global study evaluated the efficacy and safety of veliparib in combination with whole-brain radiation therapy (WBRT) in patients with brain metastases from non-small cell lung cancer (NSCLC). Three-hundred and seven patients with brain metastases from NSCLC were randomized 1:1:1 to WBRT (30 Gy in 10 fractions) plus 50 mg veliparib twice daily (BID; n = 103), 200 mg veliparib BID (n = 102), or placebo BID (n = 102). Treatment began within 28 days of diagnosis. Tumor response and safety were assessed; the primary endpoint was overall survival (OS). Patients who received ≥1 dose of treatment were included in the safety analysis. All randomized patients were included in the efficacy endpoint analyses. Patient characteristics were well balanced between treatment arms. Median OS was 185 days for patients treated with WBRT plus placebo and 209 days for WBRT plus veliparib (50 or 200 mg). No statistically significant differences in OS, intracranial response rate, and time to clinical or radiographic progression between any of the treatment arms were noted. No differences were observed in adverse events (all grades) across treatment arms; nausea, fatigue, alopecia, and headache were the most commonly reported. No new safety signals were identified for veliparib. A significant unmet need for therapies that improve the outcomes of patients with brain metastases from NSCLC remains.

The ALK translocation in advanced non-small-cell lung carcinomas: preapproval testing experience at a single cancer centre.

AIMS: To study the ALK translocation in patients with advanced non-small-cell lung carcinomas (NSCLCs) seen at a European cancer centre, and its association with EGFR mutations, KRAS mutations and MET amplification. METHODS AND RESULTS: The study included samples from 86 patients diagnosed with advanced NSCLC. ALK fluorescence in-situ hybridization (FISH) was performed using the ALK break-apart probe set (Vysis). ALK FISH-positive cases were defined as those with more than 15% break-apart signals or isolated red signals in 50 cells. EGFR and KRAS mutations were determined by direct sequencing. All ALK-positive cases were analysed retrospectively for MET amplification using a FISH assay, and for ALK mutations by sequencing. We found nine (10.5%) ALK-positive cases, all in adenocarcinomas and the majority in female patients (88.9%). Signet ring cells were observed in four (44.4%) of the nine patients. None of the ALK translocated cases showed MET amplifications or EGFR, KRAS and ALK mutations. CONCLUSIONS: The prevalence of ALK translocation in an unselected population of European patients with advanced NSCLCs was 10%. This alteration was mutually exclusive with EGFR and KRAS mutations, as well as with MET amplification. If multiplexing is considered at the preanalytical phase, lung biopsy specimens are sufficient for performing several predictive assays.

No changes in hemostasis after COVID-19-heterologous vaccination schedule: A subanalysis of the phase 2 CombiVacS study.

Background: Several cases of unusual thrombotic events and thrombocytopenia were described after vaccination with recombinant adenoviral vectors encoding the spike protein antigen of SARS-CoV-2. Objectives: The objective of this study was to elucidate the impact of a COVID-19 heterologous vaccination schedule, including priming with adenovirus vaccine, on hemostasis profiles. Methods: The present study is a subanalysis of the CombiVacS clinical trial initiated in April 2021 that included adult participants previously vaccinated with a single dose of ChAdOx1-S. Between 8 and 12 weeks after vaccination, they were randomly assigned (2:1) to receive either BNT162b2 vaccine (intervention group, n = 99) or continue observation (control group, n = 50). Samples drawn before and 28 days after a vaccination with BNT162b2 were analyzed for platelet count and markers of hemostasis (D-dimer, anti-PF4 antibodies, cfDNA, PAI-1, thrombin generation, and serum capacity to activate platelets). Results: Platelet count from all participants after receiving BNT162b2 was within the normal range. Anti-PF4 antibodies were present in 26% and 18% of the subjects from the control and intervention groups, respectively, at day 28. In most cases, the levels of anti-PF4 antibodies were high before receiving BNT162b2. Serum from these participants did not activate platelets from healthy controls. There were no differences between the groups in PAI-1 and cfDNA plasma levels. According to the D-dimer plasma concentration, the thrombin generation test showed that none of the participants had a procoagulant profile. Conclusion: Our data suggest that the heterologous vaccination against COVID-19 with ChAdOx1-S and a second dose with BNT162b2 might be safe in terms of haemostasis.

Infigratinib in Patients with Recurrent Gliomas and FGFR Alterations: A Multicenter Phase II Study.

PURPOSE: FGFR genomic alterations (amplification, mutations, and/or fusions) occur in ∼8% of gliomas, particularly FGFR1 and FGFR3. We conducted a multicenter open-label, single-arm, phase II study of a selective FGFR1-3 inhibitor, infigratinib (BGJ398), in patients with FGFR-altered recurrent gliomas. PATIENTS AND METHODS: Adults with recurrent/progressive gliomas harboring FGFR alterations received oral infigratinib 125 mg on days 1 to 21 of 28-day cycles. The primary endpoint was investigator-assessed 6-month progression-free survival (PFS) rate by Response Assessment in Neuro-Oncology criteria. Comprehensive genomic profiling was performed on available pretreatment archival tissue to explore additional molecular correlations with efficacy. RESULTS: Among 26 patients, the 6-month PFS rate was 16.0% [95% confidence interval (CI), 5.0-32.5], median PFS was 1.7 months (95% CI, 1.1-2.8), and objective response rate was 3.8%. However, 4 patients had durable disease control lasting longer than 1 year. Among these, 3 had tumors harboring activating point mutations at analogous positions of FGFR1 (K656E; n = 2) or FGFR3 (K650E; n = 1) in pretreatment tissue; an FGFR3-TACC3 fusion was detected in the other. Hyperphosphatemia was the most frequently reported treatment-related adverse event (all-grade, 76.9%; grade 3, 3.8%) and is a known on-target toxicity of FGFR inhibitors. CONCLUSIONS: FGFR inhibitor monotherapy with infigratinib had limited efficacy in a population of patients with recurrent gliomas and different FGFR genetic alterations, but durable disease control lasting more than 1 year was observed in patients with tumors harboring FGFR1 or FGFR3 point mutations or FGFR3-TACC3 fusions. A follow-up study with refined biomarker inclusion criteria and centralized FGFR testing is warranted.

Immunogenic dynamics and SARS-CoV-2 variant neutralisation of the heterologous ChAdOx1-S/BNT162b2 vaccination: Secondary analysis of the randomised CombiVacS study.

Background: The CombiVacS study was designed to assess immunogenicity and reactogenicity of the heterologous ChAdOx1-S/BNT162b2 combination, and 14-day results showed a strong immune response. The present secondary analysis addresses the evolution of humoral and cellular response up to day 180. Methods: Between April 24 and 30, 2021, 676 adults primed with ChAdOx1-S were enrolled in five hospitals in Spain, and randomised to receive BNT162b2 as second dose (interventional group [IG]) or no vaccine (control group [CG]). Individuals from CG received BNT162b2 as second dose and also on day 28, as planned based on favourable results on day 14. Humoral immunogenicity, measured by immunoassay for SARS-CoV-2 receptor binding domain (RBD), antibody functionality using pseudovirus neutralisation assays for the reference (G614), Alpha, Beta, Delta, and Omicron variants, as well as cellular immune response using interferon-γ and IL-2 immunoassays were assessed at day 28 after BNT162b2 in both groups, at day 90 (planned only in the interventional group) and at day 180 (laboratory data cut-off on Nov 19, 2021). This study was registered with EudraCT (2021-001978-37) and ClinicalTrials.gov (NCT04860739). Findings: In this secondary analysis, 664 individuals (441 from IG and 223 from CG) were included. At day 28 post vaccine, geometric mean titres (GMT) of RBD antibodies were 5616·91 BAU/mL (95% CI 5296·49-5956·71) in the IG and 7298·22 BAU/mL (6739·41-7903·37) in the CG (p < 0·0001). RBD antibodies titres decreased at day 180 (1142·0 BAU/mL [1048·69-1243·62] and 1836·4 BAU/mL [1621·62-2079·62] in the IG and CG, respectively; p < 0·0001). Neutralising antibodies also waned from day 28 to day 180 in both the IG (1429·01 [1220·37-1673·33] and 198·72 [161·54-244·47], respectively) and the CG (1503·28 [1210·71-1866·54] and 295·57 [209·84-416·33], respectively). The lowest variant-specific response was observed against Omicron-and Beta variants, with low proportion of individuals exhibiting specific neutralising antibody titres (NT50) >1:100 at day 180 (19% and 22%, respectively). Interpretation: Titres of RBD antibodies decay over time, similar to homologous regimes. Our findings suggested that delaying administration of the second dose did not have a detrimental effect after vaccination and may have improved the response obtained. Lower neutralisation was observed against Omicron and Beta variants at day 180. Funding: Funded by Instituto de Salud Carlos III (ISCIII).

Rapid, scalable assessment of SARS-CoV-2 cellular immunity by whole-blood PCR.

Fast, high-throughput methods for measuring the level and duration of protective immune responses to SARS-CoV-2 are needed to anticipate the risk of breakthrough infections. Here we report the development of two quantitative PCR assays for SARS-CoV-2-specific T cell activation. The assays are rapid, internally normalized and probe-based: qTACT requires RNA extraction and dqTACT avoids sample preparation steps. Both assays rely on the quantification of CXCL10 messenger RNA, a chemokine whose expression is strongly correlated with activation of antigen-specific T cells. On restimulation of whole-blood cells with SARS-CoV-2 viral antigens, viral-specific T cells secrete IFN-γ, which stimulates monocytes to produce CXCL10. CXCL10 mRNA can thus serve as a proxy to quantify cellular immunity. Our assays may allow large-scale monitoring of the magnitude and duration of functional T cell immunity to SARS-CoV-2, thus helping to prioritize revaccination strategies in vulnerable populations.

Translational proteomics: what can you do for true patients?

Matching the right medical strategy to the right patient is the key for modern clinical oncology. To this aim, we have many delicate drugs designed to target in elegant ways critical proteins identified in cancer cells. However, clinical oncologists and multidisciplinary groups devoted to treating patients in an integrative fashion have histology and an TNM staging system as the most relevant biomarkers to decide therapeutic approaches for our patients. In addition, the most used drugs are classical chemotherapeutic compounds such as cisplatin, epirrubicin, irinotecan, oxaliplatin, and so on. Thus, new targeted therapies, surgery, radiotherapy, and chemotherapy will live together causing a duality for the immediate future. We will try to delineate unmet needs for clinical oncologists that would add value for cancer proteomics in terms of true patients.

Brain Arteriovenous Malformations: Impact of Neurologic Status, Bleeding, and Type of Treatment on Final Outcome.

BACKGROUND: Well-designed studies assessing the treatment outcome of brain arteriovenous malformations (AVMs) are infrequent and have not consistently included all of the available treatment modalities, making their results not completely generalizable. Moreover, the predictors of poor outcome are not well defined. METHODS: We performed an observational retrospective study of AVM patients. We included patients with clinical, radiologic, and outcome data, with a minimum follow-up of 1 year. Neurologic outcome was documented using the modified Rankin Scale (mRS) at the AVM diagnosis and 30 days after the treatment. RESULTS: There were 117 patients, with equal male/female proportion. The mean follow-up time was 51 months. Treatment distribution in the Spetzler-Martin grades I-III was as follows: 52 (54.6%) surgery, 31 (32.35%) radiosurgery, 2 (0.02%) embolization, and 11 (12%) conservative follow-up. Treatment distribution in Spetzler-Martin grades IV and V was as follows: 4 (20%) surgery, 7 (35%) radiosurgery, and 10 (45%) conservative follow-up. Poor neurologic outcome (mRS ≥ 3) was significantly associated with poor clinical status at diagnosis (Glasgow Coma Scale [GCS] score< 14; odds ratio [OR]: 0.20; 95% confidence interval [CI]: 0.001-0.396; p = 0.010). The rupture of the AVM was associated with poor neurologic outcome. The Lawton-Young Supplementary scale (LYSS) proved to be the most effective in predicting poor outcome. The existence of seizures, treatment-related complications, and conservative treatment was associated with the worsening of the mRS score, whereas the existence of hemorrhage was associated with the likelihood of disability. CONCLUSION: Our results suggest that poor neurologic status at diagnosis, AVM rupture, and conservative treatment were associated with worse outcome. Hemorrhage as initial presentation is related to disability, not with mRS worsening. The LYSS appeared to be the best method to predict outcome.

Potential Therapeutic Effects of the Neural Stem Cell-Targeting Antibody Nilo1 in Patient-Derived Glioblastoma Stem Cells.

Glioblastoma (GBM) is the most devastating and least treatable brain tumor with median survival <15 months and extremely high recurrence rates. Promising results of immune checkpoint blockade obtained from pre-clinical studies in mice did not translate to clinic, and new strategies are urgently needed, particularly those targeting GBM stem cells (GSCs) that are held responsible for drug resistance and tumor recurrence. Patient-derived GSC cultures are critical for finding effective brain tumor therapies. Here, we investigated the ability of the recently described monoclonal antibody Nilo1 to specifically recognize GSCs isolated from GBM surgical samples. We employed five patient-derived GSC cultures with different stemness marker expression and differentiation potential, able to recapitulate original tumors when xenotransplanted in vivo. To answer whether Nilo1 has any functional effects in patient-derived GSCs lines, we treated the cells with Nilo1 in vitro and analyzed cell proliferation, cell cycle, apoptosis, sphere formation, as well as the expression of stem vs. differentiation markers. All tested GSCs stained positively for Nilo1, and the ability of Nilo1 to recognize GSCs strongly relied on their stem-like phenotype. Our results showed that a subset of patient-derived GSCs were sensitive to Nilo1 treatment. In three GSC lines Nilo1 triggered differentiation accompanied by the induction of p21. Most strikingly, in one GSC line Nilo1 completely abrogated self-renewal and led to Bax-associated apoptosis. Our data suggest that Nilo1 targets a molecule functionally relevant for stemness maintenance and pinpoint Nilo1 as a novel antibody-based therapeutical strategy to be used either alone or in combination with cytotoxic drugs for GSC targeting. Further pre-clinical studies are needed to validate the effectiveness of GSC-specific Nilo1 targeting in vivo.

Tumor stem cells fuse with monocytes to form highly invasive tumor-hybrid cells.

The 'cancer cell fusion' theory is controversial due to the lack of methods available to identify hybrid cells and to follow the phenomenon in patients. However, it seems to be one of the best explanations for both the origin and metastasis of primary tumors. Herein, we co-cultured lung cancer stem cells with human monocytes and analyzed the dynamics and properties of tumor-hybrid cells (THC), as well as the molecular mechanisms beneath this fusion process by several techniques: electron-microscopy, karyotyping, CRISPR-Cas9, RNA-seq, immunostaining, signaling blockage, among others. Moreover, mice models were assessed for in vivo characterization of hybrids colonization and invasiveness. Then, the presence of THCs in bloodstream and samples from primary and metastatic lesions were detected by FACS and immunofluorescence protocols, and their correlations with TNM stages established. Our data indicate that the generation of THCs depends on the expression of CD36 on tumor stem cells and the oxidative state and polarization of monocytes, the latter being strongly influenced by microenvironmental fluctuations. Highly oxidized M2-like monocytes show the strongest affinity to fuse with tumor stem cells. THCs are able to proliferate, colonize and invade organs. THC-specific cell surface signature CD36+CD14+PANK+ allows identifying them in matched primary tumor tissues and metastases as well as in bloodstream from patients with lung cancer, thus functioning as a biomarker. THCs levels in circulation correlate with TNM classification. Our results suggest that THCs are involved in both origin and spread of metastatic cells. Furthermore, they might set the bases for future therapies to avoid or eradicate lung cancer metastasis.

The combination of FOLFOX4 and bevacizumab may enable salvage surgery of unresectable liver metastases in colon cancer.

Colorectal cancer treatment has experienced important advances in the last 5 years. New targeted therapies have been included in the classical regimens based on 5-fluorouracil, oxaliplatin, or irinotecan. This new approach has brought great revolution in the treatment of this type of cancer. Bevacizumab (Avastin), a new antivascular endothelial growth factor drug, has been shown to improve overall survival in combination with chemotherapy in first-line and second-line settings as compared with standard chemotherapy regimens alone. This case report demonstrates our experience with bevacizumab in a colon cancer patient with liver, lung, and regional lymph node metastases who had a relapse in the liver after adjuvant treatment with capecitabine (Xeloda). The addition of bevacizumab to the FOLFOX4 regimen resulted in a partial response that provided an opportunity for salvage hepatic surgery.

Complete and rapid response to FOLFIRI plus bevacizumab in a patient presenting with impaired liver function and poor performance status from colon cancer liver metastases.

Impaired liver function is a final complication of hepatic metastases from colon cancer. This disease status is of critical importance at first clinical presentation because of the tight therapeutic window for chemotherapy. A rapid response to treatment is required as other means of supportive care for hepatic function are limited. New targeted therapies including monoclonal antibodies directed against several proteins with key roles in colon cancer biology are now available, allowing new treatment options for this group of patients. Here, we present a patient with highly impaired liver function secondary to hepatic metastases from colon cancer that showed clinical and radiological improvement after systemic treatment including bevacizumab.

Bevacizumab: a safe and effective treatment in a patient with advanced colorectal cancer and repeated removal of metastases.

Bevacizumab has been shown to be effective combined with chemotherapy for first-line treatment of advanced colorectal cancer, but little information is available about its efficacy and safety in patients who may be candidates for surgery at any time during the disease. The case history of a female patient with colorectal cancer, undergoing surgery for liver metastases and bilateral surgery for lung metastases at different time-points during her disease, is reported. Perioperative bevacizumab administration caused no complications either associated with surgery, in the early postoperative period, or in the subsequent months.

EPO-R expression patterns in resected gastric adenocarcinoma followed by adjuvant chemoradiation treatment.

The primary aim was to determine whether Epo-R immunohistochemical expression is related to disease free survival (DFS) in specimens of GC from patients who underwent adjuvant chemoradiation. Specimens of gastric adenocarcinomas obtained from 44 patients who had undergone curative gastrectomy and adjuvant treatment were investigated immunohistochemically expression of Epo-R. Three patterns for Epo-R staining were defined: Pattern A (secretory cells-like staining), Pattern B (parietal-like staining) and Pattern C (chief-like staining). Median DFS was 38 months (CI 95%: 33-43) and 15 months (IC 95%: 3-27) in the pattern B and C, respectively, but it was not reached in the pattern A (p = 0.06). Our findings suggest that there may be a relationship between Epo-R expression and DFS in the patients with GC resected.

Drug resistance in cancer immunotherapy: new strategies to improve checkpoint inhibitor therapies.

Recent advances in pharmacological immune modulation against tumor cells has dramatically changed the paradigm of cancer treatment. Checkpoint inhibitor therapy is a form of cancer immunotherapy already in clinical setting but also under active basic and clinical investigation. Nevertheless, some patients are primary unresponsive or develop ulterior resistance to these family of drugs. This review aims to update the basic molecular mechanism of resistance as well as the current strategies for checkpoint inhibitor selection in order to propose new approaches to individualize the use of these novel therapies.

BRAF V600E Detection in Liquid Biopsies from Pediatric Central Nervous System Tumors.

Pediatric Central Nervous System (CNS) tumors are the most fatal cancer diseases in childhood. Due to their localization and infiltrative nature, some tumor resections or biopsies are not feasible. In those cases, the use of minimally invasive methods as diagnostic, molecular marker detection, prognostic or monitoring therapies are emerging. The analysis of liquid biopsies which contain genetic information from the tumor has been much more widely explored in adults than in children. We compare the detection of BRAF V600E targetable mutation by digital-PCR from cell-free-DNA and EV-derived DNA (ctDNA) in serum, plasma and cerebrospinal fluid (CSF) isolated from a cohort of 29 CNS pediatric patients. Here we demonstrate that ctDNA isolated from serum and plasma could be successfully analyzed to obtain tumor genetic information which could be used to guide critical treatment decisions.