The Use of Liquid Biopsy in the Molecular Analysis of Plasma Compared to the Tumour Tissue from a Patient with Brain Metastasis: A Case Report.

Different cancers have multiple genetic mutations, which vary depending on the affected tumour tissue. Small biopsies may not always represent all the genetic landscape of the tumour. To improve the chances of identifying mutations at different disease stages (early, during the disease course, and refractory stage), liquid biopsies offer an advantage to traditional tissue biopsy. In addition, it is possible to detect mutations related to metastatic events depending on the cancer types analysed as will be discussed in this case report, which describes a patient with brain metastasis and lung cancer that harboured K-RAS mutations both in the brain tumour and in the ctDNA present in the bloodstream.

Perspectives on emerging technologies, personalised medicine, and clinical research for cancer control in Latin America and the Caribbean.

Challenges of health systems in Latin America and the Caribbean include accessibility, inequity, segmentation, and poverty. These challenges are similar in different countries of the region and transcend national borders. The increasing digital transformation of health care holds promise of more precise interventions, improved health outcomes, increased efficiency, and ultimately reduced health-care costs. In Latin America and the Caribbean, the adoption of digital health tools is in early stages and the quality of cancer registries, electronic health records, and structured databases are problematic. Cancer research and innovation in the region are limited due to inadequate academic resources and translational research is almost fully dependent on public funding. Regulatory complexity and extended timelines jeopardise the potential improvement in participation in international studies. Emerging technologies, artificial intelligence, big data, and cancer research represent an opportunity to address the health-care challenges in Latin America and the Caribbean collectively, by optimising national capacities, sharing and comparing best practices, and transferring scientific and technical capabilities.

The genotypic and phenotypic impact of hypoxia microenvironment on glioblastoma cell lines.

BACKGROUND: Glioblastoma is a fatal brain tumour with a poor patient survival outcome. Hypoxia has been shown to reprogram cells towards a stem cell phenotype associated with self-renewal and drug resistance properties. Activation of hypoxia-inducible factors (HIFs) helps in cellular adaptation mechanisms under hypoxia. Similarly, miRNAs are known to be dysregulated in GBM have been shown to act as critical mediators of the hypoxic response and to regulate key processes involved in tumorigenesis. METHODS: Glioblastoma (GBM) cells were exposed to oxygen deprivation to mimic a tumour microenvironment and different cell aspects were analysed such as morphological changes and gene expression of miRNAs and survival genes known to be associated with tumorigenesis. RESULTS: It was observed that miR-128a-3p, miR-34-5p, miR-181a/b/c, were down-regulated in 6 GBM cell lines while miR-17-5p and miR-221-3p were upregulated when compared to a non-GBM control. When the same GBM cell lines were cultured under hypoxic microenvironment, a further 4-10-fold downregulation was observed for miR-34-5p, miR-128a-3p and 181a/b/c while a 3-6-fold upregulation was observed for miR-221-3p and 17-5p for most of the cells. Furthermore, there was an increased expression of SOX2 and Oct4, GLUT-1, VEGF, Bcl-2 and survivin, which are associated with a stem-like state, increased metabolism, altered angiogenesis and apoptotic escape, respectively. CONCLUSION: This study shows that by mimicking a tumour microenvironment, miRNAs are dysregulated, stemness factors are induced and alteration of the survival genes necessary for the cells to adapt to the micro-environmental factors occurs. Collectively, these results might contribute to GBM aggressiveness.

Identification of mutant K-RAS in pituitary macroadenoma.

PURPOSE: RAS genes are among the most frequently mutated genes in cancer, where their mutation frequency varies according to the distinct RAS isoforms and tumour types. Despite occurring more prevalent in malignant tumours, RAS mutations were also observed in few benign tumours. Pituitary adenomas are examples of benign tumours which vary in size and aggressiveness. The present study was performed to investigate, via liquid biopsy and tissue analysis, the presence of K-RAS mutations in a pituitary macroadenoma. METHODS: Molecular analysis was performed to investigate K-RAS mutations using the droplet digital PCR (ddPCR) method by evaluating both plasma (liquid biopsy) and the solid tumour of a patient diagnosed with a giant clinically non-functioning pituitary tumour. RESULTS: The patient underwent surgical resection due to visual loss, and the histopathological analysis showed a gonadotrophic pituitary macroadenoma. The molecular analysis revealed the presence of mutant K-RAS both in the plasma and in the tumour tissue which, to our knowledge, has not been previously reported in the literature. CONCLUSION: Our findings highlight the exceptional capacity of the digital PCR in detecting low frequency mutations (below 1%), since we detected, for the first time, K-RAS mutations in pituitary macroadenoma. The potential impact of K-RAS mutations in these tumours should be further investigated.

Evaluation of KRAS Concomitant Mutations in Advanced Lung Adenocarcinoma Patients.

Background and Objectives: One of the most frequently mutated oncogenes in cancer belongs to the Ras family of proto-oncogenes, which encode distinct key signaling events. RAS gain-of-function mutations are present in ~30% of all human cancers, with KRAS being the most frequently mutated isoform showing alterations in different cancer types including lung cancer. This study aimed to investigate the incidence of KRAS mutations, and concomitant mutations, in advanced non-small cell lung adenocarcinoma patients. Materials and Methods: This was a retrospective study, where genomic DNA extracted from paraffin-embedded tumor tissues from 121 Brazilian advanced non-small cell lung adenocarcinoma patients were analyzed to evaluate via Next Generation Sequencing (NGS) the incidence of KRAS mutations and co-occurring mutations and correlate, when possible, to clinicopathological characteristics. Statistical analyses were performed to calculate the prevalence of mutations and to investigate the association between mutational status, mutation type, and sex. Results: The results showed a prevalence of male (N = 63; 54.8%) compared to female patients (N = 52, 45.2%), and mutant KRAS was present in 20.86% (24/115) of all samples. Interestingly, 33.3% of the mutant KRAS samples showed other mutations simultaneously. Conclusions: This study revealed the presence of rare KRAS concomitant mutations in advanced lung adenocarcinoma patients. Further investigation on the importance of these genomic alterations in patient prognosis and treatment response is warranted.

Cost-effectiveness analysis comparing companion diagnostic tests for EGFR, ALK, and ROS1 versus next-generation sequencing (NGS) in advanced adenocarcinoma lung cancer patients.

BACKGROUND: The treatment of choice for advanced non-small cell lung cancer is selected according to the presence of specific alterations. Patients should undergo molecular testing for relevant modifications and the mutational status of EGFR and translocation of ALK and ROS1 are commonly tested to offer the best intervention. In addition, the tests costs should also be taken in consideration. Therefore, this work was performed in order to evaluate the cost-effectiveness of a unique exam using NGS (next generation sequencing) versus other routinely used tests which involve RT-PCR and FISH. METHODS: The target population was NSCLC, adenocarcinoma, and candidates to first-line therapy. Two strategies were undertaken, strategy 1 corresponded to sequential tests with EGFR RT-PCR, then FISH for ALK and ROS1. Strategy 2 differed from 1 in that ALK and ROS1 translocation testing were performed simultaneously by FISH. Strategy 3 considered single test next-generation sequencing, a platform that includes EGFR, ALK and ROS1 genes. A decision tree analysis was used to model genetic testing options. From the test results, a microsimulation model was nested to estimate survival outcomes and costs of therapeutic options. RESULTS: The use of NGS added 24% extra true cases as well as extra costs attributed to the molecular testing. The ICER comparing NGS with sequential tests was US$ 3479.11/correct case detected. The NGS improved a slight gain in life years and QALYs. CONCLUSION: Our results indicated that, although precise, the molecular diagnosis by NGS of patients with advanced stage NSCLC adenocarcinoma histology was not cost-effective in terms of quality-adjusted life years from the perspective of the Brazilian supplementary health system.

Current Approaches in NSCLC Targeting K-RAS and EGFR.

The research and treatment of non-small cell lung cancer (NSCLC) have achieved some important advances in recent years. Nonetheless, the overall survival rates for NSCLC remain low, indicating the importance to effectively develop new therapies and improve current approaches. The understanding of the function of different biomarkers involved in NSCLC progression, survival and response to therapy are important for the development of early detection tools and treatment options. Epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene homolog (K-RAS) are two of the main significant biomarkers for the management of NSCLC. Mutations in these genes were associated with development and response to therapies. For example, the use of small molecule tyrosine kinase (TK) inhibitors and immunotherapy has led to benefits in some, but not all patients with altered EGFR. In contrast, there is still no effective approved drug to act upon patients harbouring K-RAS mutations. In addition, K-RAS mutations have been associated with lack of activity of TK inhibitors. However, promising approaches aimed to inhibit mutant K-RAS are currently under study. Therefore, this review will discuss these approaches and also EGFR therapies, and hopefully, it will draw attention to the need of continued research in the field in order to improve the outcomes in NSCLC patients.

KRAS mutations: variable incidences in a Brazilian cohort of 8,234 metastatic colorectal cancer patients.

BACKGROUND: KRAS mutations are frequently found in colorectal cancer (CRC) indicating the importance of its genotyping in the study of the molecular mechanisms behind this disease. Although major advances have occurred over the past decade, there are still important gaps in our understanding of CRC carcinogenesis, particularly whether sex-linked factors play any role. METHODS: The profile of KRAS mutations in the Brazilian population was analyzed by conducting direct sequencing of KRAS codons 12 and 13 belonging to 8,234 metastatic CRC patient samples. DNA was extracted from paraffin-embedded tissue, exon 1 was amplified by PCR and submitted to direct sequencing. The data obtained was analysed comparing different geographical regions, gender and age. RESULTS: The median age was 59 years and the overall percentage of wild-type and mutated KRAS was 62.8% and 31.9%, respectively. Interestingly, different percentages of mutated KRAS patients were observed between male and female patients (32.5% versus 34.8%, respectively; p = 0.03). KRAS Gly12Asp mutation was the most prevalent for both genders and for most regions, with the exception of the North where Gly12Val was the most frequent mutation found. CONCLUSIONS: To the best of our knowledge this is one of the largest cohorts of KRAS genotyping in CRC patients and the largest to indicate a higher incidence of KRAS mutation in females compared to males in Brazil. Nevertheless, further research is required to better address the impact of gender differences in colorectal cancer.

The potential of circulating cell-free RNA in CNS tumor diagnosis and monitoring: A liquid biopsy approach.

Early detection of malignancies, through regular cancer screening, has already proven to have potential to increase survival rates. Yet current screening methods rely on invasive, expensive tissue sampling that has hampered widespread use. Liquid biopsy is noninvasive and represents a potential approach to precision oncology, based on molecular profiling of body fluids. Among these, circulating cell-free RNA (cfRNA) has gained attention due to its diverse composition and potential as a sensitive biomarker. This review provides an overview of the processes of cfRNA delivery into the bloodstream and the role of cfRNA detection in the diagnosis of central nervous system (CNS) tumors. Different types of cfRNAs such as microRNAs (miRNAs), long noncoding RNAs (lncRNAs) and circular RNAs (circRNAs) have been recognized as potential biomarkers in CNS tumors. These molecules exhibit differential expression patterns in the plasma, cerebrospinalfluid (CSF) and urine of patients with CNS tumors, providing information for diagnosing the disease, predicting outcomes, and assessing treatment effectiveness. Few clinical trials are currently exploring the use of liquid biopsy for detecting and monitoring CNS tumors. Despite obstacles like sample standardization and data analysis, cfRNA shows promise as a tool in the diagnosis and management of CNS tumors, offering opportunities for early detection, personalized therapy, and improved patient outcomes.

Artificial Intelligence and cancer: Profile of registered clinical trials.

Artificial Intelligence (AI) has made significant strides due to advancements in processing algorithms and data availability. Recent years have shown a resurgence in AI, driven by breakthroughs in deep machine learning. AI has attracted particular interest in the medical sector, especially in the field of personalized medicine, which for example uses large-scale genomic and molecular data to predict individual patient treatment responses. The applications of AI in disease diagnosis, monitoring, and treatment are expanding rapidly, leading to a growing number of registered trials. Therefore, this study aimed to identify and evaluate clinical trials registered between January 1st 2016, and September 30th 2023 that connect AI and cancer. Our findings show that the number of clinical trials linking AI with cancer research has grown significantly compared to other diseases, with colorectal and breast tumour types showing the highest number of registered trials. The most frequent intervention was disease diagnosis and monitoring. Regarding countries, China and the United States hold the highest numbers of registered trials. In conclusion, oncology is a field with a great interest in AI, where the developed countries are leading the studies in this field. Unfortunately, developing countries are still crawling in this aspect and government policies should be made to improve that area.

The role of palmitoylation in regulating Ras localization and function.

Ras GTPases are important regulators of pathways controlling proliferation, differentiation and transformation. Three ubiquitously expressed almost identical Ras genes are not functionally redundant; this has been attributed to their distinctive trafficking and localization profiles. A palmitoylation cycle controls the correct compartmentalization of H-Ras and N-Ras. We review recent data that reveal how this cycle can be regulated by membrane organization to influence the spatiotemporal signalling of Ras.

Recent advances in the use of liquid biopsy to fight central nervous system tumors.

Brain tumors are considered one of the deadliest types of cancer, being challenging to treat, especially due to the blood-brain barrier, which has been linked to treatment resistance. The genomic classification of brain tumors has been helping in the diagnostic precision, however tumor heterogeneity in addition to the difficulties to obtain tissue biopsies, represent a challenge. The biopsies are usually obtained either via neurosurgical removal or stereotactic tissue biopsy, which can be risky procedures for the patient. To overcome these challenges, liquid biopsy has become an interesting option by constituting a safer procedure than conventional biopsy, which may offer valuable cellular and molecular information representative of the whole organism. Besides, it is relatively easy to obtain such as in the case of blood (venipuncture) and urine sample collection. In the present comprehensive review, we discuss the newest information regarding liquid biopsy in the brain tumors' field, methods employed, the different sources of bio-fluids and their potential circulating targets.

Clinical Cancer Research in South America and Potential Health Economic Impacts.

BACKGROUND: Increased global cancer incidence rates have led to a growing demand for cancer diagnosis and treatment, as well as basic and clinical research on the subject. The expansion of clinical cancer trials beyond the borders of highly developed countries has aided the arrival of these assessments in South American countries. In this context, this study's objective is to highlight clinical cancer trial profiles developed and sponsored by pharmaceutical companies and conducted in South American countries from 2010 to 2020. METHODS: This study comprises descriptive and retrospective research conducted following a search for clinical trials (phases I, II and III), registered at clinicaltrials.gov, carried out in Latin American countries and sponsored by pharmaceutical companies ("Argentina", "Brazil", "Chile", "Peru", "Colombia", "Ecuador", "Uruguay", "Venezuela", "Paraguay", "Bolivia"), registered between 1 January 2010 and 31 December 2020. A total of 1451 clinical trials were retrieved, of which 200 trials unrelated to cancer were excluded and 646 duplicates were removed, leading to a final total of 605 clinical trials employing qualitative and quantitative analyses. RESULTS: A 122% increase in the number of clinical trial registrations from 2010 to 2020 was noted, with a prevalence of phase III studies (431 trials of a total of 605). Lung (119), breast (100), leukemia (42), prostate (39) and melanoma (32) were the main cancers tested for new drugs. CONCLUSIONS: The data reported herein indicate the need for strategic basic and clinical research planning that considers South American epidemic cancer profiles.

Liquid biopsy evaluation of circulating tumor DNA, miRNAs, and cytokines in meningioma patients.

Introduction: Liquid biopsy is a non-invasive method used to detect cancer and monitor treatment responses by analyzing blood or other bodily fluids for cancer biomarkers. Meningiomas are the most common primary central nervous system tumors, and biomarkers play a crucial role in their diagnosis, prognosis, and treatment monitoring. The World Health Organization (WHO) classifies meningiomas based on tumor grades and molecular alterations in genes such as in NF2, AKT1, TRAF7, SMO, PIK3CA, KLF4, SMARCE1, BAP1, H3K27me3, TERT promoter, and CDKN2A/B. Liquid biopsy, specifically cell-free DNA (cfDNA) analysis, has shown potential for monitoring meningiomas as it can detect ctDNA release in the blood, unaffected by the blood-brain barrier. MicroRNAs (miRNAs) have also been found to be deregulated in various cancers, including meningiomas, presenting potential as diagnostic biomarkers. Additionally, studying cytokines in the tumor microenvironment may aid in establishing prognostic or diagnostic panels for meningiomas. Methods: In the present study we analyzed the DNA coming from both the plasma and tumor samples, in addition to analyze miRNA-21 and cytokines in the plasma of 28 meningioma patients. Discussion and Conclusion: Our findings indicate that the detection of ctDNA in the plasma of meningioma patients is feasible. However, it's important to note that certain challenges persist when comparing plasma DNA analysis to that of tumor tissues. In our study, we observed a paired identification of mutations in only one patient, highlighting the complexities involved. Furthermore, we successfully identified miR-21 and cytokines in the plasma samples. Notably, our analysis of Interleukin 6 (IL-6) unveiled higher expression in the clear cell subtype compared to the other types. Despite the ongoing research, the clinical implementation of liquid biopsy in meningiomas remains somewhat limited. Nevertheless, our promising results underscore the need for further investigation.

Real-World Evidence of Health Outcomes Related to Lung Stereotactic Body Radiation Therapy in Brazil.

PURPOSE: Stereotactic body radiation therapy (SBRT) is an effective option for patients with both early-stage and oligometastatic non-small-cell lung cancer (NSCLC). However, data from Latin America are limited. Therefore, the aim of this study was to investigate the real-world outcomes of applying SBRT for lung lesions in a Brazilian institution. METHODS: This study investigated a consecutive cohort of patients treated with SBRT for lung lesions (primary and metastasis). The study primary outcome was local control rates per lesion. Secondary outcomes included progression-free survival (PFS), overall survival (OS), and toxicity. RESULTS: Between 2015 and 2019, a total of 216 patients received SBRT and were included in the study. The median follow-up was 24.5 months (5-70), primary NSCLC corresponded to 70% (n = 151) and nonprimary lung lesions to 30% (n = 65), respectively. Stage I NSCLC represented 56% (85 of 151) of the NSCLC cohort. The average number of fractions and total dose prescribed was 5 (3-10)/59 Gy (50-62 Gy). For stage I NSCLC (all lesions treated with a biologically effective dose [10] > 100 Gy), 2-year local control, OS, and PFS were 93.4%, 81.6%, and 80.7%, respectively. For stage IV lesions, if biologically effective dose (10) > 100 Gy or < 100 Gy, 2-year local control was 95.8/86.4% (P = .03), 2-year-OS was 81.6/60.5% (P = .006), and 2-year PFS was 38.9/17.9% (P = .10). Late toxicity was observed in 16.2% (n = 35) of the total cases. CONCLUSION: Our results indicate that SBRT is effective (high local control and acceptable toxicity) for treating malignant lung lesions in a real-world scenario in Latin America.

P-glycoprotein and cancer: what do we currently know?

Acquired resistance during cancer treatment is unfortunately a frequent event. There are several reasons for this, including the ability of the ATP-binding cassette transporters (ABC transporters), which are integral membrane proteins, to export chemotherapeutic molecules from the interior of the tumor cells. One important member of this family is the protein known as Permeability Glycoprotein (P-Glycoprotein, P-gp or ABCB1). Its clinical relevance relies mainly on the fact that the inhibition of P-gp and other ABC transporters could result in the reversal of the multidrug resistance (MDR) phenotype in some patients. Recently, other roles apart from being a key player in MDR, have emerged for P-gp. Therefore, this review discusses the relationship between P-gp and MDR, in addition to the possible role of this protein as a biomarker in cancer.

Tyrosine phosphorylation of Munc18c on residue 521 abrogates binding to Syntaxin 4.

BACKGROUND: Insulin stimulates exocytosis of GLUT4 from an intracellular store to the cell surface of fat and muscle cells. Fusion of GLUT4-containing vesicles with the plasma membrane requires the SNARE proteins Syntaxin 4, VAMP2 and the regulatory Sec1/Munc18 protein, Munc18c. Syntaxin 4 and Munc18c form a complex that is disrupted upon insulin treatment of adipocytes. Munc18c is tyrosine phosphorylated in response to insulin in these cells. Here, we directly test the hypothesis that tyrosine phosphorylation of Munc18c is responsible for the observed insulin-dependent abrogation of binding between Munc18c and Syntaxin 4. RESULTS: We show that Munc18c is directly phosphorylated by recombinant insulin receptor tyrosine kinase in vitro. Using pull-down assays, we show that phosphorylation abrogates binding of Munc18c to both Syntaxin 4 and the v-SNARE VAMP2, as does the introduction of a phosphomimetic mutation into Munc18c (Y521E). CONCLUSION: Our data indicate that insulin-stimulated tyrosine phosphorylation of Munc18c impairs the ability of Munc18c to bind its cognate SNARE proteins, and may therefore represent a regulatory step in GLUT4 traffic.

K-RAS4A: Lead or Supporting Role in Cancer Biology?

The RAS oncogene is one of the most frequently mutated genes in human cancer, with K-RAS having a leading role in tumorigenesis. K-RAS undergoes alternative splicing, and as a result its transcript generates two gene products K-RAS4A and K-RAS4B, which are affected by the same oncogenic mutations, are highly homologous, and are expressed in a variety of human tissues at different levels. In addition, both isoforms localise to the plasma membrane by distinct targeting motifs. While some evidence suggests nonredundant functions for both splice variants, most work to date has focused on K-RAS4B, or even just K-RAS (i.e., without differentiating between the splice variants). This review aims to address the most relevant evidence published regarding K-RAS4A and to discuss if this "minor" isoform could also play a leading role in cancer, concluding that a significant body of evidence supports a leading role rather than a supporting (or secondary) role for K-RAS4A in cancer biology.

Dealing with lung cancer in the COVID-19 scenario (A review).

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has caused the coronavirus disease 2019 (COVID-19), first appeared in December 2019 in Wuhan (China) and quickly spread worldwide and has since been assigned a pandemic status. This affected the worlds' social interactions, including within medical practices, thus interfering with routine treatments for a variety of diseases including cancer. Different studies have addressed the fact that patients with cancer are often immunocompromised, making them more susceptible to infections. Since COVID-19 frequently causes respiratory distress, patients with lung cancer are considered to be a high-risk group. Genes that have been indicated to mediate viral entry into host cells such as angiotensin-converting enzyme 2 and transmembrane protease serine 2 are expressed in the lung tissue, a fact that could partially explain COVID-19 pathogenesis and lung involvement. Therefore, the current study offers a disease overview including molecular aspects behind the infection and provide a perspective on already published Chinese data plus recommendations for the management of lung cancer patients according to the two main lung cancer types and stages: non-small cell lung cancer and small cell lung cancer. This review aimed to add to the collective effort of selecting the most appropriate guidelines to follow for the treatment of these patients.

Access of Patients With Lung Cancer to High Technology Radiation Therapy in Brazil.

PURPOSE: Lung cancer is a global health problem, with more than 220,000 new cases and 150,000 deaths per year in the United States. Likewise, in Brazil, lung cancer is the most lethal cancer with 30,200 new cases expected in 2020. Regarding treatment types, radiation therapy (RT) represents an important approach, since 60%-70% of the patients will receive this modality of treatment during the course of their disease. However, access to RT remains challenging because of the socioeconomic inequalities in the Brazilian population, where approximately 100,000 patients/year die without access to RT. This work provides an overview on the availability of high technology RT in Brazil. METHODS: A retrospective study was performed using the Brazilian Radiotherapy Census, local public and private databases, and the current literature published in 2019. RESULTS: The Brazilian radiotherapy network relies on approximately 363 linear accelerators and 20 cobalt machines that remain operational. Most of these machines are installed at public health facilities. Regarding high technology, intensity-modulated RT is available in 53.7% (n = 130) and volumetric modulated arc therapy in 28.5% (n = 69) of the institutions, although only 19.8% (n = 48) of those facilities are capable of performing image-guided RT using cone beam computed tomography. Considering only the public health care system, the scenario is more restricted, with 40.1% (n = 65) of the institutions offering intensity-modulated RT, 21% (n = 34) volumetric modulated arc therapy, and 14.8% (n = 24) using cone beam computed tomography. Because of these scare resources, only 16% of Radiation Departments offer stereotactic body RT. CONCLUSION: Brazil still needs to improve and provide high and safer RT technologies to patients with lung cancer across all Brazilian regions to attend the population needs and obtain better patient outcomes.