Liquid biopsy in non-small cell lung cancer-current status and future outlook-a narrative review.

Lung cancer ranks first as the cause of cancer-associated deaths gobally. The American Cancer Society estimates for 228,820 new cases and 135,720 deaths from lung cancer in the United States for the year 2020. Targeted treatment options have rapidly emerged for non-small cell lung cancer (NSCLC) within the past decade. Screening for molecular aberrations is mainly done by tissue biopsy. However, in some cases a biopsy is not possible, or patients do not consent to it. Hence, liquid biopsy remains the only option. Relevant data about the topic of liquid biopsy, with a special focus on NSCLC, was obtained via a PubMed search. We included mainly literature published from 2010 onwards, omitting older studies whenever possible. With this review of the literature, we give an overview of different liquid biopsy approaches, as well as their respective advantages and disadvantages. We have reviewed the assessment of epidermal growth factor receptor (EGFR) mutation status in particular, and go into detail with current use of liquid biopsy in everyday clinical practice. Today, liquid biopsy is still infrequently used, depending on the treatment center, but popularity is steadily increasing. Various different approaches are already available, but costs and level of sensitivity significantly differ between techniques. By using liquid biopsy more widely in selected patients, complication rates can be reduced, and constant disease monitoring is made considerably easier.

Current Knowledge about Mechanisms of Drug Resistance against ALK Inhibitors in Non-Small Cell Lung Cancer.

Non-small cell lung cancer (NSCLC) accounts for the majority of lung cancer subtypes. Two to seven percent of NSCLC patients harbor gene rearrangements of the anaplastic lymphoma kinase (ALK) gene or, alternatively, harbor chromosomal fusions of ALK with echinoderm microtubule-associated protein-like 4 (EML4). The availability of tyrosine kinase inhibitors targeting ALK (ALK-TKIs) has significantly improved the progression-free and overall survival of NSCLC patients carrying the respective genetic aberrations. Yet, increasing evidence shows that primary or secondary resistance to ALK-inhibitors during the course of treatment represents a relevant clinical problem. This necessitates a switch to second- or third-generation ALK-TKIs and a close observation of NSCLC patients on ALK-TKIs during the course of treatment by repetitive molecular testing. With this review of the literature, we aim at providing an overview of current knowledge about resistance mechanisms to ALK-TKIs in NSCLC.

Distribution and prognostic significance of gluconeogenesis and glycolysis in lung cancer.

Inhibition of glycolysis has been considered as a therapeutic approach in aggressive cancers including lung cancer. Abbreviated gluconeogenesis, mediated by phosphoenolpyruvate carboxykinase (PEPCK), was recently discovered to partially circumvent the need for glycolysis in lung cancer cells. However, the interplay of glycolysis and gluconeogenesis in lung cancer is still poorly understood. Here, we analyzed the expression of GLUT1, the prime glucose transporter, and of PCK1 and PCK2, the cytoplasmic and mitochondrial isoforms of PEPCK, in 450 samples of non-small cell lung cancer (NSCLC) and in 54 NSCLC metastases using tissue microarrays and whole tumor sections. Spatial distribution was assessed by automated image analysis. Additionally, glycolytic and gluconeogenic gene expression was inferred from The Cancer Genome Atlas (TCGA) datasets. We found that PCK2 was preferentially expressed in the lung adenocarcinoma subtype, while GLUT1 expression was higher in squamous cell carcinoma. GLUT1 and PCK2 were inversely correlated, GLUT1 showing elevated expression in larger tumors while PCK2 was highest in smaller tumors. However, a mixed phenotype showing the presence of both, glycolytic and gluconeogenic cancer cells was frequent. In lung adenocarcinoma, PCK2 expression was associated with significantly improved overall survival, while the opposite was found for GLUT1. The metabolic tumor microenvironment and the 3-dimensional context play an important role in modulating both pathways, since PCK2 expression preferentially occurred at the tumor margin and hypoxia regulated both, glycolysis and gluconeogenesis, in NSCLC cells in vitro, albeit in opposite directions. PCK1/2 expression was enhanced in metastases compared to primary tumors, possibly related to the different environment. The results of this study show that glycolysis and gluconeogenesis are activated in NSCLC in a tumor size and oxygenation modulated manner and differentially correlate with outcome. The frequent co-activation of gluconeogenesis and glycolysis in NSCLC should be considered in potential future therapeutic strategies targeting cancer cell metabolism.

Prediction of Postoperative Clinical Outcomes in Resected Stage I Non-Small Cell Lung Cancer Focusing on the Preoperative Glasgow Prognostic Score.

Background: The Glasgow Prognostic Score (GPS), which consists of albumin and C-reactive protein (CRP), may predict overall survival (OS) in cancer patients. The aim of this retrospective analysis was to evaluate the clinical impact of the preoperative GPS on patients with resected early stage non-small cell lung cancer (NSCLC). Methods: 300 patients with curatively resected stage I NSCLC were followed-up for OS, recurrence-free survival (RFS), cancer-specific survival (CSS), and death from other causes. Results: 229 patients (76%) had a preoperative GPS of 0, and 71 (24%) a GPS ≥ 1. The three-year probabilities of RFS, OS, CSS, and death from other causes were 81%, 84%, 88%, and 96% in patients with GPS = 0, and 79%, 74%, 91%, and 82% in patients with a GPS ≥ 1, respectively. GPS ≥ 1 was significantly associated with a higher risk of death from other causes (p = 0.022), serving as an independent predictor of death from other causes (p = 0.034). Pathologically elevated CRP levels (CRP > 5 mg/L) were found in 91 patients (30%). The mean CRP level was 7.88 ± 15.80 mg/L (0.5-135.6 mg/L). Pre-treatment CRP level was significantly associated with coronary heart disease (p < 0.0001), histology (p = 0.013), tumor size (p = 0.018), tumor stage (p = 0.002), and vascular invasion (p = 0.017). Conclusion: The preoperative GPS predicts adverse survival outcomes in patients with resected stage I NSCLC.

Oncogene addiction and tumor mutational burden in non-small-cell lung cancer: Clinical significance and limitations.

Lung cancer incidence has increased worldwide over the past decades, with non-small cell lung cancer (NSCLC) accounting for the vast majority (85%) of lung cancer specimens. It is estimated that lung cancer causes about 1.7 million global deaths per year worldwide. Multiple trials have been carried out, with the aim of finding new effective treatment options. Lately, special focus has been placed on immune checkpoint (PD1/PD-L1) inhibitors which impact the tumor immune microenvironment. Tumor mutational burden (TMB) has been found to predict response to immune checkpoint inhibitors. Conversely, recent studies have weakened the significance of TMB as a predictor of response to therapy and survival. In this review article, we discuss the significance of TMB, as well as possible limitations. Furthermore, we give a concise overview of mutations frequently found in NSCLC, and discuss the significance of oncogene addiction in lung cancer as an essential driver of tumorigenesis and tumor progression.

The Biological and Clinical Relevance of Inhibitor of Growth (ING) Genes in Non-Small Cell Lung Cancer.

Carcinogenic mutations allow cells to escape governing mechanisms that commonly inhibit uncontrolled cell proliferation and maintain tightly regulated homeostasis between cell death and survival. Members of the inhibition of growth (ING) family act as tumor suppressors, governing cell cycle, apoptosis and cellular senescence. The molecular mechanism of action of ING genes, as well as their anchor points in pathways commonly linked to malignant transformation of cells, have been studied with respect to a variety of cancer specimens. This review of the current literature focuses specifically on the action mode of ING family members in lung cancer. We have summarized data from in vitro and in vivo studies, highlighting the effects of varying levels of ING expression in cancer cells. Based on the increasing insight into the function of these proteins, the use of ING family members as clinically useful biomarkers for lung cancer detection and prognosis will probably become routine in everyday clinical practice.

Gluconeogenesis in cancer cells - Repurposing of a starvation-induced metabolic pathway?

Cancer cells constantly face a fluctuating nutrient supply and interference with adaptive responses might be an effective therapeutic approach. It has been discovered that in the absence of glucose, cancer cells can synthesize crucial metabolites by expressing phosphoenolpyruvate carboxykinase (PEPCK, PCK1 or PCK2) using abbreviated forms of gluconeogenesis. Gluconeogenesis, which in essence is the reverse pathway of glycolysis, uses lactate or amino acids to feed biosynthetic pathways branching from glycolysis. PCK1 and PCK2 have been shown to be critical for the growth of certain cancers. In contrast, fructose-1,6-bisphosphatase 1 (FBP1), a downstream gluconeogenesis enzyme, inhibits glycolysis and tumor growth, partly by non-enzymatic mechanisms. This review sheds light on the current knowledge of cancer cell gluconeogenesis and its role in metabolic reprogramming, cancer cell plasticity, and tumor growth.

Non-Smoking-Associated Lung Cancer: A distinct Entity in Terms of Tumor Biology, Patient Characteristics and Impact of Hereditary Cancer Predisposition.

Non-small cell lung cancer (NSCLC) in non-, and especially in never-smoking patients is considered a biologically unique type of lung cancer, since risk factors and tumorigenic conditions, other than tobacco smoke, come into play. In this review article, we comprehensively searched and summarized the current literature with the aim to outline what exactly triggers lung cancer in non-smokers. Changes in the tumor microenvironment, distinct driver genes and genetic pathway alterations that are specific for non-smoking patients, as well as lifestyle-related risk factors apart from tobacco smoke are critically discussed. The data we have reviewed highlights once again the importance of personalized cancer therapy, i.e., careful molecular and genetic assessment of the tumor to provide tailored treatment options with optimum chances of good response-especially for the subgroups of never-smokers.

The WHO Grade I Collagen-forming Meningioma Produces Angiogenic Substances. A New Meningioma Entity.

BACKGROUND: Meningiomas arise from arachnoid cap cells, the so-called meningiothelial cells. They account for 20-36% of all primary intracranial tumours, and arise with an annual incidence of 1.8-13 per 100,000 individuals/year. According to their histopathological features meningiomas are classified either as grade I (meningiothelial, fibrous/fibroblastic, transitional/mixed, psammomatous, angiomatous, microcystic, secretory and the lympholasmacyterich sub-type), grade II (atypical and clear-cell sub-type) or grade III (malignant or anaplastic phenotype). CASE REPORT: A 62-year-old female patient presented to the hospital because of progressive obliviousness and concentration difficulties. In the magnetic resonance imaging (MRI) of the brain, an occipital convexity-meningioma was found in the left hemisphere, which was subsequently resected. Within the tumour tissue there were multiple spheroid precipitates, i.e. secretion products that turned out to consist of collagen. Part of the tumour cells displayed positive reactions for vasogenic substances, namely for vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR). Correspondingly, the diagnosis "WHO Grade I collagen-forming meningioma" seems to be most appropriate. CONCLUSION: The "WHO Grade I collagen-forming meningioma" reported herein produces collagen and angiogenic substances. To the best of our knowledge, no such entity has been reported on in previous literature. We propose this collagen-producing meningioma as a novel WHO grade I meningioma sub-type.

Genomic characterization of endometrial stromal sarcomas with array comparative genomic hybridization.

INTRODUCTION: The endometrial stromal sarcoma (ESS) is a very rare uterine sarcoma, counting for 1-3% of all gynecologic malignancies. ESS represents 0.2-8% of all uterine malignant tumors and accounts for about 10% of all uterine sarcomas. With regard to chromosomal aberrations, very little is known about benign and malignant endometrial stromal tumors. METHODS: 30 tumors, consisting of 4 cases of benign endometrial stromal nodule (ESN), 22 cases of low-grade ESS and 4 cases of undifferentiated endometrial sarcoma (UES), were analyzed by array-comparative genomic hybridization (aCGH). RESULTS: ESN did not show many copy number changes (CNCs) by aCGH. Frequent losses could be identified on chromosomes 7p and 19, and gains on chromosomes 1q, 6p and 8q. Low-grade ESS presented as a very heterogeneous group. 90% (20/22) of cases displayed aberrations. Most frequent changes were losses on chromosomes 7 and 22, and gains on chromosome 1q or 11. UES showed a high number of chromosomal aberrations and on every chromosome CNCs were detected. Most frequent changes were losses on chromosomes 1q, 2q (3/4, 75%) and 13, and gains on chromosomes 1q and 17p. CONCLUSION: Our data shows an increasing number of CNCs from ESN to low-grade ESS and to UES. However, the chromosomal aberrations differ considerably between the investigated ESN-, low-grade ESS- and UES cases and thus, a linear tumor progression seems to be unlikely.

Rare case of a primary intracranial chondrosarcoma.

BACKGROUND: Intracranial chondrosarcomas comprise 6% of all skull base neoplasms and account for 0.15% of all intracranial tumors. They are potentially fatal, invading the brain and elevating intracranial pressure by progressive enlargement. Diplopia and headache are the most common clinical symptoms. Previous data indicate a particularly aggressive behavior of intracranial chondrosarcomas. CASE REPORT: A 17-year-old female patient presented to the hospital with focal seizures. A magnetic resonance imaging (MRI) scan revealed a brain tumor located in the right meso-temporal region. Total tumor resection, followed by conformal proton therapy was performed. The tumor displayed a chondroid differentiation, and accordingly, a chondrosarcoma was diagnosed. At follow-up investigation two years after the resection of the tumor, the patient was in a good general state of health and no tumor recurrence had occurred. DISCUSSION AND CONCLUSION: Intracranial chondrosarcoma is a differential diagnosis for intracranial tumors of the skull base. State-of-the-art therapy should comprise of surgical resection and adjuvant radiotherapy. Previously published data about intracranial chondrosarcomas indicate the extreme aggressiveness of this tumor entity.

A unilateral dermatomal venous malformation.

Venous malformations (VMs) are the most common vascular malformations, forming 44% to 64% of all vascular malformations. We report a case of a patient suffering from unilateral dermatomal VM. The VM was strictly confined to the right C6 dermatome. We propose that unilateral dermatomal VM is a prime example of somatic mosaicism in vascular development. Unilateral dermatomal VM seems to have a similar pathogenesis to the Sturge-Weber syndrome and may also be caused by somatic mutations disrupting the development of skin veins.

Progressive multifocal leukoencephalopathy--a case report and review of the literature.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system which affects the white matter and is caused by reactivation of the JC polyomavirus. CASE REPORT: We report the case of a 63-year-old man with chronic lymphocytic leukemia who was treated with fludarabine; rituximab and fludarabine; fludarabine, cyclophsphamide and rituximab; and lenalidomide. While he underwent chemotherapy, the patient was diagnosed with PML. After stabilization of PML, the patient underwent non-myeloablative allogeneic bone marrow transplantation as a treatment for chronic lymphocytic leukemia. Unfortunately, after several opportunistic infections, the patient died. DISCUSSION: The patient underwent allogeneic bone marrow transplantation with the expectation that donor-derived competent immunological cells would migrate into the cerebral lesions, maintaining immunological response. The effect of bone marrow transplantation in patients with PML requires investigation in larger patient series.

Non-coding RNAs and lipid metabolism.

A high percentage of the mammalian genome consists of non-coding RNAs (ncRNAs). Among ncRNAs two main subgroups have been identified: long ncRNAs (lncRNAs) and micro RNAs (miRNAs). ncRNAs have been demonstrated to play a role in a vast variety of diseases, since they regulate gene transcription and are involved in post-transcriptional regulation. They have the potential to function as molecular signals or as guides for transcription factors and to regulate epigenetic modifiers. In this literature review we have summarized data on miRNAs and lncRNAs and their involvement in dyslipidaemia, atherosclerosis, insulin resistance and adipogenesis. Outlining certain ncRNAs as disease biomarkers and/or therapeutic targets, and testing them in vivo, will be the next steps in future research.

Targeted treatment of ovarian cancer--the multiple - kinase - inhibitor sorafenib as a potential option.

Ovarian cancer (OC) is ranked as the eighth most common gynecological malignancy and is the leading cause of gynecological cancer-related deaths in women worldwide. The response to platinum- and taxane-based chemotherapy is very often poor, and targeted-therapeutics are currently being tested in patients with OC. Sorafenib is a non-selective multiple kinase inhibitor with proven antiproliferative effects in thyroid, renal and hepatocellular carcinoma. Sorafenib acts on vascular endothelial growth factor (VEGF) and on platelet-derived growth factor (PDGF) related pathways. It also influences the rat sarcoma proto-oncogene/rat fibrosarcoma protein kinase/mitogen activated protein kinase (RAS/RAF/MAPK) pathway and blocks tumor growth factor beta-1 (TGF-ß-1)-mediated epithelial-mesenchymal transition (EMT). Sorafenib also acts at the epigenetic level altering the histone acetylation pattern. There have been phase I, II and III studies investigation sorafenib in OC. We review several trials in which sorafenib has been administered as single-agent or combined with other chemotherapeutics. Unfortunately, the effect of sorafenib was usually modest and complete response was rarely observed. Adverse effects occurred frequently, including rash, diarrhea, edema and weight gain. Sorafenib evidently blocks EMT in vitro. However, in the conducted trials, sorafenib was administered to patients with highly advanced tumors. We posit that blocking EMT may be more effective in early-stage disease. We also presume that sorafenib would work particularly well in the treatment of clear cell OC, since this type of OC has different molecular characteristics from usual OC and is less sensitive to standard chemotherapy. Furthermore, the combination of sorafenib with other multiple-kinase inhibiting agents, e.g. ABT-869, a targeted-agent mainly acting in the VEGF and PDGF pathways, should be investigated in further detail. It is probable that synergistic effects can be achieved.

Malignant ascites in ovarian cancer and the role of targeted therapeutics.

Ovarian cancer (OC) is the eighth most lethal gynecological malignancy and the main cause of gynecological cancer death in industrialized countries. Malignant ascites is often found in OC, with about 10% of patients suffering from recurrent OC. Tumor cells in OC-associated malignant ascites promote disease recurrence and patient mortality is mainly associated with widespread metastasis to serosal surfaces and accompanying peritoneal effusions. Targeted therapies have recently been developed as novel therapeutic options for malignant ascites. The tri-functional anti-epithelial cell adhesion molecule and anti-cluster of differentiation 3 monoclonal antibody catumaxumab has been assessed in the therapy of malignant ascites, and proven to significantly reduce the ascitic flow rate when applied into the peritoneal cavity. The anti-angiogenic targeted agent bevacizumab has also shown good effects in the symptomatic treatment of malignant ascites, significantly prolonging the time until the next paracentesis. Vascular endothelial growth factor (VEGF) Trap, or aflibercept, is a fusion protein that inhibits VEGF-receptor binding. Aflibercept has proven to be effective in reduction of ascites, diminishing clinical symptoms of ascites and prolonging the time to next paracentesis. All three agents we review in the present article are effective in symptomatic control of ascites, leading to a rapid reduction of effusion and prolonging the time interval between paracenteses. However, no improvement in overall survival was observed in any of the clinical trials reported. We, thus, conclude that further investigations on larger patient series are needed to clarify whether the reduction of ascites by these targeted agents leads to a prolongation in tumor-related survival or not.

A case report of an ependymoblastoma in the rectovaginal space and a review of the literature.

INTRODUCTION: Ependymomas are glial neoplasms that arise at or close to the inner ependymal surface of the ventricular system. They are most frequently located intraventricularly, but they may also occur in the spinal cord or, very seldom, at extraneural sites. Here we report a case of an ectopic ependymoma, arising in the pelvic cavity. CASE REPORT: A 35 year-old female patient was diagnosed with a suspect tumor mass in the rectovaginal space, infiltrating the perirectal adipose tissue and the vagina. Three years later, liver and peritoneal metastases of the same tumor were diagnosed. Two years after that, the patient experienced a recidive in the left adnexa. Histological analysis revealed an anaplastic tumor of dual nature, comprising of mesenchymal and epithelial features. There were ependymoma-like rosettes and pseudorosettes, indicating an ependymal differentiation. Immunohistochemically, the tumor was positive for epithelial membrane antigen (EMA) and glial fibrillary acidic protein (GFAP). Accordingly, the diagnosis "grade 3 ependymoma, i.e. ependymoblastoma" was made. REVIEW: Ependymomas are most frequently located in the ventricular system, but may also occur in the spinal cord or rarely at extraneural sites. Extraneural ependymomas represent a diagnostic challenge, since they can mimic other tumor types and the immunohistochemical profile may be non-specific. The most important features of ependymal differentiation are rosette- or pseudorosette formation. Extraneural ependymomas can be located in the ovary or elsewhere in the pelvic cavity. Locations in the lung, liver and the small bowel have also been described. In the present article we review several reported cases of ectopic, extraneural ependymomas. DISCUSSION: The origin of extraneural ependymomas is not completely clarified. They probably arise from glial tissue that is a residue from the embryonic development, pinched-off from the neural tube during its closure. We propose, that extraneural ependymoma should be considered in differential diagnosis for anaplastic tumors of the pelvic cavity.

Targeting signaling pathways in epithelial ovarian cancer.

UNLABELLED: Ovarian carcinoma (OC) is the most lethal gynecological malignancy. Response to platinum-based chemotherapy is poor in some patients and, thus, current research is focusing on new therapy options. The various histological types of OC are characterized by distinctive molecular genetic alterations that are relevant for ovarian tumorigenesis. The understanding of these molecular pathways is essential for the development of novel therapeutic strategies. PURPOSE: We want to give an overview on the molecular genetic changes of the histopathological types of OC and their role as putative therapeutic targets. In Depth Review of Existing Data: In 2012, the vascular endothelial growth factor (VEGF) inhibitor, bevacizumab, was approved for OC treatment. Bevacizumab has shown promising results as single agent and in combination with conventional chemotherapy, but its target is not distinctive when analyzed before treatment. At present, mammalian target of rapamycin (mTOR) inhibitors, poly-ADP-ribose polymerase (PARP) inhibitors and components of the EGFR pathway are in the focus of clinical research. Interestingly, some phytochemical substances show good synergistic effects when used in combination with chemotherapy. CONCLUSION: Ongoing studies of targeted agents in conjunction with chemotherapy will show whether there are alternative options to bevacizumab available for OC patients. Novel targets which can be assessed before therapy to predict efficacy are needed. The assessment of therapeutic targets is continuously improved by molecular pathological analyses on tumor tissue. A careful selection of patients for personalized treatment will help to reduce putative side effects and toxicity.