Enhancing patient outcomes: Integrating electronic cardiology consultation in primary care for cancer patients.

BACKGROUND: The prevalence of cancer patients with concomitant cardiovascular (CV) disease is on the rise due to improved cancer prognoses. The aim of this study is to evaluate the long-term outcomes of cancer patients referred to a cardiology department (CD) via primary care using e-consultation. METHODS: We analysed data from cancer patients with prior referrals to a CD between 2010 and 2021 (n = 6889) and compared two care models: traditional in-person consultations and e-consultations. In e-consultation model, cardiologists reviewed electronic health records (e-consultation) to determine whether the demand could be addressed remotely or necessitated an in-person consultation. We used an interrupted time series regression model to assess outcomes during the two periods: (1) time to cardiology consultation, (2) rates of all-cause and CV related hospital admissions and (3) rates of all-cause and CV-related mortality within the first year after the initial consultation or e-consultation at the CD. RESULTS: Introduction of e-consultation for cancer patients referred to cardiology care led to a 51.8% reduction (95%CI: 51.7%-51.9%) in waiting times. Furthermore, we observed decreased 1-year incidence rates, with incidence rate ratios (iRRs) [IC95%] of .75 [.73-.77] for CV-related hospitalizations, .43 [.42-.44] for all-cause hospitalizations, and .87 [.86-.88] for all-cause mortality. CONCLUSIONS: Compared to traditional in-person consultations, an outpatient care program incorporating e-consultation for cancer patients significantly reduced waiting times for cardiology care and demonstrated safety, associated with lower rates of hospital admissions.

Red Blood Cells Protein Profile Is Modified in Breast Cancer Patients.

Metastasis is the primary cause of death for most breast cancer (BC) patients who succumb to the disease. During the hematogenous dissemination, circulating tumor cells interact with different blood components. Thus, there are microenvironmental and systemic processes contributing to cancer regulation. We have recently published that red blood cells (RBCs) that accompany circulating tumor cells have prognostic value in metastatic BC patients. RBC alterations are related to several diseases. Although the principal known role is gas transport, it has been recently assigned additional functions as regulatory cells on circulation. Hence, to explore their potential contribution to tumor progression, we characterized the proteomic composition of RBCs from 53 BC patients from stages I to III and IV, compared with 33 cancer-free controls. In this work, we observed that RBCs from BC patients showed a different proteomic profile compared to cancer-free controls and between different tumor stages. The differential proteins were mainly related to extracellular components, proteasome, and metabolism. Embryonic hemoglobins, not expected in adults' RBCs, were detected in BC patients. Besides, lysosome-associated membrane glycoprotein 2 emerge as a new RBCs marker with diagnostic and prognostic potential for metastatic BC patients. Seemingly, RBCs are acquiring modifications in their proteomic composition that probably represents the systemic cancer disease, conditioned by the tumor microenvironment.

Noninvasive detection of microsatellite instability in patients with endometrial cancer.

The analysis of mismatch repair proteins in solid tissue is the standard of care (SoC) for the microsatellite instability (MSI) characterization in endometrial cancer (EC). Uterine aspirates (UAs) or circulating-DNA (cfDNA) samples capture the intratumor heterogeneity and provide a more comprehensive and dynamic molecular diagnosis. Thus, MSI analysis by droplet-digital PCR (ddPCR) in UAs and cfDNA can provide a reliable tool to characterize and follow-up the disease. The UAs, paraffin-embedded tumor tissue (FFPE) and longitudinal plasma samples from a cohort of 90 EC patients were analyzed using ddPCR panel and compared to the SoC. A high concordance (96.67%) was obtained between the analysis of MSI markers in UAs and the SoC. Three discordant cases were validated as unstable by ddPCR on FFPE samples. Besides, a good overall concordance (70.27%) was obtained when comparing the performance of the ddPCR assay on UAs and cfDNA in high-risk tumors. Importantly, our results also evidenced the value of MSI analysis to monitor the disease evolution. MSI evaluation in minimally invasive samples shows great accuracy and sensitivity and provides a valuable tool for the molecular characterization and follow-up of endometrial tumors, opening new opportunities for personalized management of EC.

Effect of capmatinib on the pharmacokinetics of substrates of CYP3A (midazolam) and CYP1A2 (caffeine) in patients with MET-dysregulated solid tumours.

BACKGROUND: Preclinical studies showed that capmatinib reversibly inhibits cytochrome P450 (CYP) 3A4 and CYP1A2 in a time-dependent manner. In this study, we evaluated the effect of capmatinib on the exposure of sensitive substrates of CYP3A (midazolam) and CYP1A2 (caffeine) in patients with mesenchymal-epithelial transition (MET)-dysregulated solid tumours. Besides pharmacokinetics, we assessed treatment response and safety. METHODS: This open-label, multicentre, single-sequence study consisted of a molecular prescreening period, a screening/baseline period of ≤28 days and a drug-drug interaction (DDI) phase of 12 days. On day 1 of the DDI phase, 37 patients received a single oral dose of midazolam 2.5 mg and caffeine 100 mg as a two-drug cocktail. Capmatinib 400 mg bid was administered from day 4 on a continuous dosing schedule. On day 9 of the DDI phase, patients were re-exposed to midazolam and caffeine. After the DDI phase, patients received capmatinib on continuous 21-day cycles until disease progression at the discretion of the investigator. RESULTS: A 22% (90% confidence interval [CI] 7-38%) increase in the midazolam maximum plasma concentration (Cmax ) was noted when administered with capmatinib, but this was deemed not clinically meaningful. Co-administration with capmatinib resulted in 134% (90% CI 108-163%) and 122% (90% CI 95-153%) increases in the caffeine area under the plasma concentration-time curve from time zero to infinity (AUCinf ) and area under the plasma concentration-time curve from time zero to the last measurable point (AUClast ), respectively, with no change in Cmax . Adverse events were consistent with the known capmatinib safety profile. No new safety signals were reported in this study. CONCLUSION: The data from this study demonstrated that capmatinib is a moderate CYP1A2 inhibitor. Capmatinib administration did not cause any clinically relevant changes in midazolam exposure.

Quantitative proteomics in medication-related osteonecrosis of the jaw: A proof-of-concept study.

OBJECTIVE: Medication-related osteonecrosis of the jaw (MRONJ) is a paradoxical effect associated with bone-modifying agents (BMAs) and other drugs. Currently, no valuable diagnostic or prognosis biomarkers exist. The goal of this research was to study MRONJ-related salivary proteome. MATERIALS AND METHODS: This case-control aimed to study salivary proteome in MRONJ versus control groups (i) formed from BMAs consumers and (ii) healthy individuals to unravel biomarkers. Thirty-eight samples of unstimulated whole saliva (18 MRONJ patients, 10 BMA consumers, and 10 healthy controls) were collected. Proteomic analysis by SWATH-MS coupled with bioinformatics analysis was executed. RESULTS: A total of 586 proteins were identified, 175 proteins showed significant differences among MRONJ versus controls. SWATH-MS revealed differentially expressed proteins among three groups, which have never been isolated. These proteins had distinct roles including cell envelope organization, positive regulation of vesicle fusion, positive regulation of receptor binding, or regulation of low-density lipoprotein particle clearance. Integrative analysis prioritized 3 proteins (MMP9, AACT, and HBD). Under receiver-operating characteristic analysis, this panel discriminated MRONJ with a sensitivity of 90% and a specificity of 78.9%. CONCLUSION: These findings may inform a novel biomarker panel for MRONJ prediction or diagnosis. Nonetheless, further research is needed to validate this panel.

Ascites-Derived Organoids to Depict Platinum Resistance in Gynaecological Serous Carcinomas.

Gynaecological serous carcinomas (GSCs) constitute a distinctive entity among female tumours characterised by a very poor prognosis. In addition to late-stage diagnosis and a high rate of recurrent disease associated with massive peritoneal carcinomatosis, the systematic acquisition of resistance to first-line chemotherapy based on platinum determines the unfavourable outcome of GSC patients. To explore the molecular mechanisms associated with platinum resistance, we generated patient-derived organoids (PDOs) from liquid biopsies of GSC patients. PDOs are emerging as a relevant preclinical model system to assist in clinical decision making, mainly from tumoural tissue and particularly for personalised therapeutic options. To approach platinum resistance in a GSC context, proficient PDOs were generated from the ascitic fluid of ovarian, primary peritoneal and uterine serous carcinoma patients in platinum-sensitive and platinum-resistant clinical settings from the uterine aspirate of a uterine serous carcinoma patient, and we also induced platinum resistance in vitro in a representative platinum-sensitive PDO. Histological and immunofluorescent characterisation of these ascites-derived organoids showed resemblance to the corresponding original tumours, and assessment of platinum sensitivity in these preclinical models replicated the clinical setting of the corresponding GSC patients. Differential gene expression profiling of a panel of 770 genes representing major canonical cancer pathways, comparing platinum-sensitive and platinum-resistant PDOs, revealed cellular response to DNA damage stimulus as the principal biological process associated with the acquisition of resistance to the first-line therapy for GSC. Additionally, candidate genes involved in regulation of cell adhesion, cell cycles, and transcription emerged from this proof-of-concept study. In conclusion, we describe the generation of PDOs from liquid biopsies in the context of gynaecological serous carcinomas to explore the molecular determinants of platinum resistance.

Liquid biopsy-based microRNA models as potential biomarkers of bowel conditions.

MicroRNAs detected in liquid biopsies have demonstrated to have potential as biomarkers of benign and malignant bowel conditions. Numerous studies have reported on the combination of different microRNAs to improve the diagnostic capabilities in the detection of bowel conditions. This editorial will be reviewing the best scientific evidence available to this date on studies showing microRNA models with sensitivity and specificity values. Also, the current challenges on how to implement microRNAs in the routine clinical practice are exposed.

Integrity and quantity of salivary cell-free DNA as a potential molecular biomarker in oral cancer: A preliminary study.

BACKGROUND: Differences in cell-free DNA (cfDNA) fragments have been described as a valuable tool to distinguish cancer patients from healthy individuals. We aim to investigate the concentration and integrity of cfDNA fragments in saliva from oral squamous cell carcinoma (OSCC) patients and healthy individuals in order to explore their value as diagnostic biomarkers. METHODS: Saliva samples were collected from a total of 34 subjects (19 OSCC patients and 15 healthy controls). The total concentration of salivary cfDNA (scfDNA) was determined using a fluorometry method and quantitative real-time polymerase chain reaction (qPCR). To evaluate the scfDNA quantity and integrity, qPCR targeting Arthobacter luteus (ALU) sequences at three amplicons of different lengths (60, 115, and 247 bp, respectively) was carried out. ScfDNA integrity indexes (ALU115/ALU60 and ALU247/ALU60) were calculated as the ratio between the absolute concentration of the longer amplicons 115 bp and 247 bp and the total scfDNA amount (amplicon 60 bp). RESULTS: The total scfDNA concentration (ALU60) was higher in OSCC than in healthy donors, but this trend was not statistically significant. The medians of scfDNA integrity indexes, ALU115/ALU60 and ALU247/ALU60, were significantly higher in OSCC, showing area under the curve values of 0.8211 and 0.7018, respectively. CONCLUSION: Our preliminary results suggest that scfDNA integrity indexes (ALU115/ALU60 and ALU247/ALU60) have potential as noninvasive diagnostic biomarkers for OSCC.

Increased quality of life in patients with breakthrough cancer pain after individualized therapy: the CAVIDIOM study.

Aim: To evaluate the quality of life (QoL) in patients with breakthrough cancer pain (BTcP) in Spanish medical oncology departments. Patients & methods: In a prospective, observational, multicenter study, we assessed QoL using the EQ-5D-5L instrument at baseline and after 15 and 30 days of individualized BTcP therapy, as well as BTcP characteristics and treatment. Results: Patients (n = 118) were mainly women, over 64 years old and with advanced cancer. QoL improved at 15 (p = 0.013) and 30 days (p = 0.011) versus baseline. Individualized BTcP therapy consisted mostly of rapid-onset opioids (transmucosal fentanyl at doses of 67-800 µg) according to the physician evaluation. BTcP improved, including statistically significant reductions in intensity, duration, number of episodes in the last 24 h and time to onset of BTcP relief. Conclusion: QoL increased after individualized pain therapy in patients with advanced cancer and BTcP in medical oncology departments.

Cancer patients can experience flares of pain, called breakthrough pain (BTcP), despite treatment with painkillers. Although BTcP can be excruciating, its intensity and other characteristics depend on several factors, including its treatment. However, even if treated, BTcP can impair quality of life for cancer patients. We assessed quality of life in 118 patients with advanced cancer and BTcP treated in 13 medical oncology departments across Spain. We treated BTcP with individualized therapy, taking into account both pain-related and patient-related factors. We also measured quality of life using a specific, widely-used questionnaire at the study visits: at onset of individualized pain therapy and after 3, 15 and 30 days' treatment. At each visit, flare-up pain therapy was adjusted or maintained as necessary. Throughout the study, quality of life and sleep quality improved for all participants. Furthermore, there was a greater reduction in intensity, duration and frequency of BTcP. The most common treatments for flare-ups were low doses of rapid-onset opioids (fentanyl given by sublingual, buccal or nasal administration), which were much better tolerated than high-dose opioids. Overall, the study showed that quality of life in patients with advanced cancer and BTcP increased after individualized pain therapy, mainly with low doses of rapid-onset opioids.

Thirty-second sit-to-stand test as an alternative for estimating peak oxygen uptake and 6-min walking distance in women with breast cancer: a cross-sectional study.

PURPOSE: To determine whether the 30-s sit-to-stand (30STS) test can be a valid tool for estimating and stratifying peak oxygen uptake (VO2peak) and 6-min walking distance (6MWD) in women with breast cancer. METHODS: This cross-sectional study uses data from the ONCORE randomized controlled trial, including 120 women aged 18-70 years with early-stage breast cancer under treatment with anthracycline and/or anti-HER2 antibodies. Participant characteristics were collected at baseline and pooled data from functional assessment (30STS test, relative and absolute VO2peak, and 6MWD) were collected at baseline and post-intervention (comprehensive cardio-oncology rehabilitation program vs. usual care). Bivariate correlations and multivariate linear regression analyses were performed to study the relationship between functional test variables. RESULTS: The number of repetitions in the 30STS test showed (i) a moderate correlation with relative VO2peak (ml/kg/min) (r = 0.419; p < 0.001; n = 126), (ii) a weak correlation with absolute VO2peak (ml/min) (r = 0.241; p = 0.008; n = 120), and (iii) a moderate correlation with the 6MWD (r = 0.440; p < 0.001; n = 85). The ONCORE equations obtained from the multivariate regression models allowed the estimation of VO2peak and 6MWD (r2 = 0.390; r2 = 0.261, respectively) based on the 30STS test, and its stratification into tertiles (low, moderate, and high). CONCLUSION: The 30STS test was found to be a useful tool to estimate VO2peak and/or 6MWD in women with early-stage breast cancer. Its use may facilitate the assessment and stratification of functional capacity in this population for the implementation of therapeutic exercise programs if cardiopulmonary exercise testing (CPET) or 6MWT are not available. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03964142. Registered on 28 May 2019. Retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT03964142.

Genome-wide DNA methylation profiling in tongue squamous cell carcinoma.

OBJECTIVES: To provide a comprehensive characterization of DNA methylome of oral tongue squamous cell carcinoma (OTSCC) and identify novel tumor-specific DNA methylation markers for early detection using saliva. MATERIAL AND METHODS: Genome-wide DNA methylation analysis including six OTSCC matched adjacent non-tumoral tissue and saliva was performed using Infinium MethylationEPIC array. Differentially methylated levels of selected genes in our OTSCC cohort were further validated using OTSCC methylation data from The Cancer Genome Atlas database (TCGA). The methylation levels of a set of tumor-specific hypermethylated genes associated with a downregulated expression were evaluated in saliva. Receiver operating characteristic (ROC) curves were performed to assess the diagnostic value of DNA methylation markers. RESULTS: A total of 25,890 CpGs (20,505 hypomethylated and 5385 hypermethylated) were differentially methylated (DMCpGs) between OTSCC and adjacent non-tumoral tissue. Hypermethylation of 11 tumor-specific genes was validated in OTSCC TCGA cohort. Of these 11 genes, A2BP1, ANK1, ALDH1A2, GFRA1, TTYH1, and PDE4B were also hypermethylated in saliva. These six salivary methylated genes showed high diagnostic accuracy (≥0.800) for discriminating patients from controls. CONCLUSIONS: This is the first largest genome-wide DNA methylation study on OTSCC that identifies a group of novel tumor-specific DNA methylation markers with diagnostic potential in saliva.

Improving the Management of Endometrial Cancer Patients through the Use of Liquid Biopsy Analyses: A Case Report.

Endometrial cancer (EC) is the 4th most common neoplasm of the female genital tract, with 15-20% of patients being of high risk of recurrence which leads to a significant decrease in patient survival. Current therapeutic options for patients with EC are poor, being the combined therapy of carboplatin and paclitaxel the standard of care, with limited efficacy. Therefore, new therapeutic options and better monitoring tools are needed to improve the management of the disease. In the current case report, we showcase the value of liquid biopsy analyses in a microsatellite instability EC patient with initially good prognosis that however underwent rapid progression disease within 6 months post-surgery; through the study of plasma cfDNA/ctDNA dynamics to assess the tumour evolution during treatment, as well as the study of the uterine aspirate as a valuable sample that captures the intra-tumour heterogeneity that allows a comprehensive genomic profiling of the disease to identify potential therapeutic options. Furthermore, preclinical models were generated at the time of tumour progression to assess the efficacy of the identified targeted therapies.

Immunotherapy in nonsmall-cell lung cancer: current status and future prospects for liquid biopsy.

Immunotherapy has been one of the great advances in the recent years for the treatment of advanced tumors, with nonsmall-cell lung cancer (NSCLC) being one of the cancers that has benefited most from this approach. Currently, the only validated companion diagnostic test for first-line immunotherapy in metastatic NSCLC patients is testing for programmed death ligand 1 (PD-L1) expression in tumor tissues. However, not all patients experience an effective response with the established selection criteria and immune checkpoint inhibitors (ICIs). Liquid biopsy offers a noninvasive opportunity to monitor disease in patients with cancer and identify those who would benefit the most from immunotherapy. This review focuses on the use of liquid biopsy in immunotherapy treatment of NSCLC patients. Circulating tumor cells (CTCs), cell-free DNA (cfDNA) and exosomes are promising tools for developing new biomarkers. We discuss the current application and future implementation of these parameters to improve therapeutic decision-making and identify the patients who will benefit most from immunotherapy.

M-TRAP: Safety and performance of metastatic tumor cell trap device in advanced ovarian cancer patients.

OBJECTIVE: Despite radical surgery and chemotherapy, most patients with ovarian cancer die due to disease progression. M-Trap is an implantable medical device designed to capture peritoneal disseminated tumor cells with the aim to focalize the disease. This trial analyzed the safety and performance of the device. METHODS: This first-in-human prospective, multi-center, non-blinded, single-arm study enrolled 23 women with high-grade serous advanced ovarian cancer. After primary or interval debulking surgery, 3 M-Trap devices were placed in the peritoneum of the abdominal cavity. 18-months post-implantation or at disease progression, devices were initially removed by laparoscopy. The primary safety endpoint was freedom from device and procedure-related major adverse events (MAEs) through 6-months post-implantation compared to an historical control. The primary performance endpoint was histopathologic evidence of tumor cells capture. RESULTS: Only one major adverse event was attributable to the device. 18 women were free of device and procedure related MAEs (78.3%). However, the primary safety endpoint was not achieved (p = 0.131), primarily attributable to the greater surgical complexity of the M-Trap patient population. 62% of recurrent patients demonstrated tumor cell capture in at least one device with a minimal tumor cell infiltration. No other long-term device-related adverse events were reported. The secondary performance endpoint demonstrated a lack of disease focalization. CONCLUSIONS: The M-Trap technology failed to meet its primary safety objective, although when adjusted for surgical complexity, the study approved it. Likewise, the devices did not demonstrate the anticipated benefits in terms of tumor cell capture and disease focalization in recurrent ovarian cancer.

A randomized trial to evaluate the impact of exercise-based cardiac rehabilitation for the prevention of chemotherapy-induced cardiotoxicity in patients with breast cancer: ONCORE study protocol.

BACKGROUND: Anthracyclines and monoclonal antibodies against human epidermal growth factor receptor-2 (HER2) are frequently used to treat breast cancer but they are associated with risk of developing cardiotoxicity. Implementation of cardioprotective strategies as part of breast cancer treatment are needed. To date, a limited number of studies have examined the effectiveness of cardiac rehabilitation programs or exercise programs in the prevention of cardiotoxicity through an integral assessment of cardiac function. The ONCORE study proposes an exercise-based cardiac rehabilitation program as a non-pharmacological tool for the management of chemotherapy-induced cardiotoxicity. METHODS: The study protocol describes a prospective, randomized controlled trial aimed to determine whether an intervention through an exercise-based CR program can effectively prevent cardiotoxicity induced by anthracyclines and/or anti-HER2 antibodies in women with breast cancer. Three hundred and forty women with breast cancer at early stages scheduled to receive cardiotoxic chemotherapy will be randomly assigned (1:1) to participation in an exercise-based CR program (intervention group) or to usual care and physical activity recommendation (control group). Primary outcomes include changes in left ventricular ejection fraction and global longitudinal strain as markers of cardiac dysfunction assessed by transthoracic echocardiography. Secondary outcomes comprise levels of cardiovascular biomarkers and cardiopulmonary function through peak oxygen uptake determination, physical performance and psychosocial status. Supervised exercise program-related outcomes including safety, adherence/compliance, expectations and physical exercise in- and out-of-hospital are studied as exploratory outcomes. Transthoracic echocardiography, clinical test and questionnaires will be performed at the beginning and two weeks after completion of chemotherapy. DISCUSSION: The growing incidence of breast cancer and the risk of cardiotoxicity derived from cancer treatments demand adjuvant cardioprotective strategies. The proposed study may determine if an exercise-based CR program is effective in minimizing chemotherapy-induced cardiotoxicity in this population of women with early-stage breast cancer. The proposed research question is concrete, with relevant clinical implications, transferable to clinical practice and achievable with low risk. Trial registration ClinicalTrials.gov Identifier: NCT03964142. Registered on 28 May 2019. Retrospectively registered. https://clinicaltrials.gov/ct2/show/NCT03964142.

Dissecting Breast Cancer Circulating Tumor Cells Competence via Modelling Metastasis in Zebrafish.

BACKGROUND: Cancer metastasis is a deathly process, and a better understanding of the different steps is needed. The shedding of circulating tumor cells (CTCs) and CTC-cluster from the primary tumor, its survival in circulation, and homing are key events of the metastasis cascade. In vitro models of CTCs and in vivo models of metastasis represent an excellent opportunity to delve into the behavior of metastatic cells, to gain understanding on how secondary tumors appear. METHODS: Using the zebrafish embryo, in combination with the mouse and in vitro assays, as an in vivo model of the spatiotemporal development of metastases, we study the metastatic competency of breast cancer CTCs and CTC-clusters and the molecular mechanisms. RESULTS: CTC-clusters disseminated at a lower frequency than single CTCs in the zebrafish and showed a reduced capacity to invade. A temporal follow-up of the behavior of disseminated CTCs showed a higher survival and proliferation capacity of CTC-clusters, supported by their increased resistance to fluid shear stress. These data were corroborated in mouse studies. In addition, a differential gene signature was observed, with CTC-clusters upregulating cell cycle and stemness related genes. CONCLUSIONS: The zebrafish embryo is a valuable model system to understand the biology of breast cancer CTCs and CTC-clusters.

Clinical significance of a microRNA signature for the identification and predicting prognosis in colorectal cancers with mucinous differentiation.

Accumulating evidence supports the fact that the mere presence of mucinous differentiation in colorectal cancer (CRC), rather than its proportion, is a more accurate representative of a particular CRC subtype with distinct clinical and molecular features. In addition, the prognostic significance of the mucinous carcinoma (MC) subtype remains poorly understood and biomarkers have been barely explored in this disease. Herein, we have performed a systematic and comprehensive analysis in MCs and non-MCs and identified a panel of microRNAs (miRNAs) that are differentially expressed between these two subtypes of CRC. Next, we interrogated their clinical significance and demonstrated their robust diagnostic and prognostic clinical ability in CRCs with mucinous differentiation. Finally, we established an integrative risk-assessment model by combining the miRNA-based risk scores together with TNM staging, which was a superior predictor of prognosis in mucinous CRC patients. Collectively, we report a novel miRNA biomarker panel for the identification and predicting survival in CRC patients with mucinous differentiation.

Relevance of CTC Clusters in Breast Cancer Metastasis.

Metastasis is the major cause of mortality in patients with breast cancer; however, the mechanisms of tumor cell dissemination and metastasis formation are not well established yet. The study of circulating tumour cells (CTCs), the metastatic precursors of distant disease, may help in this search. CTCs can be found in the blood of cancer patients as single cells or as tumor cell aggregates, known as CTC clusters. CTC clusters have differential biological features such as an enhanced survival and metastatic potential, and they hold great promises for the evaluation of prognosis, diagnosis and therapy of the metastatic cancer. The analysis of CTC clusters offers new insights into the mechanism of metastasis and can guide towards the development of new diagnostic and therapeutic strategies to suppress cancer metastasis. This has become possible thanks to the development of improved technologies for detection of CTCs and CTC clusters. However, more efficient methods are needed in order to address important questions regarding the metastatic potential of CTC and future clinical applications. In this chapter, we explore the current knowledge on the role of CTC clusters in breast cancer metastasis, their origin, metastatic advantages and clinical importance.

Proteomic Characterization of Epithelial-Like Extracellular Vesicles in Advanced Endometrial Cancer.

Endometrial cancer (EC) is the most frequent gynecological cancer. Tumor dissemination affecting ∼20% of EC patients is characterized at the primary carcinoma by epithelial-to-mesenchymal transition (EMT) associated with myometrial infiltration. At distant sites, the interaction of circulating tumor cells (CTCs) with the microenvironment is crucial for metastatic colonization, with a participation of the extracellular vesicles (EVs). We comprehensively approached these primary and secondary sites to study the impact of tumor EVs on the metastatic efficiency of CTCs in EC. Tumor EVs in circulation reproduce the epithelial phenotype predominant in the primary carcinoma, whereas CTCs are characterized by an EMT phenotype. We modeled this EMT-related clinical scenario in the Hec1A endometrial cell line and characterized the epithelial-like EVs in circulation by SILAC proteome analysis. The identification of proteins involved in cell-cell and cell-matrix interaction and binding, together with in vitro evidence of an improved adhesion of CTC to a functionalized endothelium, suggests a contribution of the epithelial-like EVs in the homing of CTCs at metastatic sites. Accordingly, adhesion protein LGALS3BP was found to be significantly enriched in circulating EVs from a cohort of EC patients with a high risk of recurrence by targeted proteomics (multiple reaction monitoring), highlighting its potential in liquid biopsy in EC.