Screening for Epidermal Growth Factor Receptor Mutations in Lung Cancer

Lung, breast, colorectal, and prostate cancers are the most incident worldwide. Optimal population-based cancer screening methods remain an unmet need, since cancer detection at early stages increases the prospects of successful and curative treatment, leading to a lower incidence of recurrences. Moreover, the current parameters for cancer patients’ stratification have been associated with divergent outcomes. Therefore, new biomarkers that could aid in cancer detection and prognosis, preferably detected by minimally invasive methods are of major importance. Aberrant DNA methylation is an early event in cancer development and may be detected in circulating cell-free DNA (ccfDNA), constituting a valuable cancer biomarker. Furthermore, DNA methylation is a stable alteration that can be easily and rapidly quantified by methylation-specific PCR methods. Thus, the main goal of this review is to provide an overview of the most important studies that report methylation biomarkers for the detection and prognosis of the four major cancers after a critical analysis of the available literature. DNA methylation-based biomarkers show promise for cancer detection and management, with some studies describing a “PanCancer” detection approach for the simultaneous detection of several cancer types. Nonetheless, DNA methylation biomarkers still lack large-scale validation, precluding implementation in clinical practice.

https://www.mdpi.com/2073-4409/9/3/624/pdf

DNA Methylation-Based Testing in Liquid Biopsies as Detection and Prognostic Biomarkers for the Four Major Cancer Types

Molecularly targeted therapies and immune checkpoint inhibitors have markedly improved the therapeutic management of advanced lung cancer. However, it still remains the leading cause of cancer-related mortality worldwide, with disease stage at diagnosis representing the main prognostic factor. Detection of lung cancer at an earlier stage of disease, potentially susceptible of curative resection, can be critical to improve patients survival. Low-dose computed tomography (LDCT) screening of high-risk patients has been demonstrated to reduce mortality from lung cancer, but can be also associated with high false-positive rate, thus often resulting in unnecessary interventions for patients. Novel sensitive and specific biomarkers for identification of high-risk subjects and early detection that can be used alternatively and/or complement current routine diagnostic procedures are needed. Liquid biopsy has recently demonstrated its clinical usefulness in advanced NSCLC as a surrogate of tissue biopsy for noninvasive assessment of specific genomic alterations, thereby providing prognostic and predictive information. Different biosources from liquid biopsy, including cell free circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), exosomes and tumor-educated platelets (TEPs), have also been widely investigated for their potential role in lung cancer diagnosis. This review will provide an overview on the circulating biomarkers being evaluated for lung cancer detection, mainly focusing on results from most recent studies, the techniques developed to perform their assessment in blood and other biologic fluids and challenges in their clinical applications.

Liquid biopsy for lung cancer early detection.

Despite advances in the management of non-small cell lung cancer, it remains to be the leading cause of cancer-related deaths worldwide primarily because of diagnosis at a late stage with an overall 5-year survival rate of 17%. A reduction in mortality was achieved by low-dose computed tomography screening of high-risk patients. However, the benefit was later challenged by the high false positive rate, resulting in unnecessary follow-ups, thus entailing a burden on both the health care system and the individual. The diagnostic dilemma imposed by imaging modalities has created a need for the development of biomarkers capable of differentiating benign nodules from malignant ones. In the past decade, with the advancements in high-throughput profiling technologies, a huge amount of work has been done to derive biomarkers to supplement clinical diagnosis. However, only a few of them have efficient sensitivity and specificity to be utilized in clinical settings. Therefore, there is an urgent need for the development of sensitive and specific means to detect and diagnose lung cancers at an early stage, when curative interventions are still possible. Due to the invasiveness of tissue biopsies and inability to capture tumor heterogeneity, nowadays enormous efforts have been invested in the development of technologies and biomarkers that enable sensitive and cost-effective testing using substrates that can be obtained in a noninvasive manner. This review, primarily focusing on liquid biopsy, summarizes all documented potential biomarkers for diagnosis, monitoring recurrence treatment response.

Biomarkers for early diagnosis, prognosis, prediction, and recurrence monitoring of non-small cell lung cancer.

Epigenetic alterations are strongly associated with the development of cancer. The aim of this study was to identify epigenetic pattern in squamous cell lung cancer (LUSC) on a genome-wide scale. Here we performed DNA methylation profiling on 24 LUSC and paired non-tumor lung (NTL) tissues by Illumina Human Methylation 450 K BeadArrays, and identified 5214 differentially methylated probes. By integrating DNA methylation and mRNA expression data, 449 aberrantly methylated genes accompanied with altered expression were identified. Ingenuity Pathway analysis highlighted these genes which were closely related to the carcinogenesis of LUSC, such as ERK family, NFKB signaling pathway, Hedgehog signaling pathway, providing new clues for understanding the molecular mechanisms of LUSC pathogenesis. To verify the results of high-throughput screening, we used 56 paired independent tissues for clinical validation by pyrosequencing. Subsequently, another 343 tumor tissues from the Cancer Genome Atlas (TCGA) database were utilized for further validation. Then, we identified a panel of DNA methylation biomarkers (CLDN1, TP63, TBX5, TCF21, ADHFE1 and HNF1B) in LUSC. Furthermore, we performed receiver operating characteristics (ROC) analysis to assess the performance of biomarkers individually, suggesting that they could be suitable as potential diagnostic biomarkers for LUSC. Moreover, hierarchical clustering analysis of the DNA methylation data identified two tumor subgroups, one of which showed increased DNA methylation. Collectively, these results suggest that DNA methylation plays critical roles in lung tumorigenesis and may potentially be proposed as a diagnostic biomarker. ChiCTR-RCC-12002830
 Date of registration: 2012–12-17.

/pdf/genome-wide-dna-methylation-profiling-reveals-novel-2hcrq2r3fz.pdf

Genome-wide DNA methylation profiling reveals novel epigenetic signatures in squamous cell lung cancer

Methylation of the cytosine residues within the CpG dinucleotides plays an important role in the fundamental cellular processes, human diseases and even cancer. The DNA methylation represents a very stable sign and therefore may be used as a valuable marker for cancer screening. Epigenetic cancer biomarkers are independent of classical morphology and thus show extensive potential to overcome the limitations of cytology. Several epigenetic cancer markers have been reported to be detectable in body fluids such as bronchial aspirate, sputum, plasma and serum.Short stature homeobox gene 2 (SHOX2) encodes a homeo-domain transcription factor, which has been identified as a close homologue of the SHOX gene and both genes are involved in skeletogenesis and heart development. Methylation of SHOX2 gene has been shown to be present at high prevalence in carcinomas of lung, however may also be used to identify other tumour entities.In the presented study, we have compared suitability of two types of material associated with lung cancer for the detection of SHOX2 methylation. We have confirmed that methylation of SHOX2 gene represents reliable marker of lung malignancies. The parallel tests in the blood plasma revealed that it may represent a good alternative material for testing of the SHOX2 methylation, making the test available to patients who are unable to undergo bronchoscopy.

/pdf/the-value-of-shox2-methylation-test-in-peripheral-blood-1euq3i6khu.pdf

The value of SHOX2 methylation test in peripheral blood samples used for the differential diagnosis of lung cancer and other lung disorders.

Lung carcinoma is the most frequently occurring cancer worldwide and the Non-small Cell Lung Cancer (NSCLC) subtype represents 80% of all diagnosed cases. Epidermal growth factor receptor (EGFR) has an important dual role in NSCLC patients. On one hand, EGFR is frequently mutated in many types of tumors, which leads to deregulation of important downstream pathways including those affecting cell proliferation, differentiation and migration. On the other hand, presence of certain activating mutation leads to increased sensitivity of EGFR to tyrosine kinase inhibitors (TKIs) treatment. Detection of these mutations is essential for identification of NSCLC patients who would profit from such therapy. However, due to the nature of available tumor material and the relatively high number of mutation hot spots, such DNA analysis may be challenging and time consuming. Here we present an approach combining direct sequencing and SNaPshot assay for identification of EGFR mutations in FFPE tissues as well as in rarely analyzed cytological smears. Using this strategy on the set of 450 tested NSCLC samples; we have identified 29 activating mutations and 14 variants, which might be interesting in predicting the efficiency of TKI therapy.

/pdf/molecular-analysis-of-egfr-gene-in-different-types-of-tumor-2nu4ygfm25.pdf

Molecular analysis of EGFR gene in different types of tumor material from NSCLC patients.

Summary The study of molecular markers in various types of human carcinomas, as well as in carcinoma of prostate, is focused on genes responsible forthe formation of carcinoma. Mutation, amplification or other changes in these genes or in their protein products are being exam ined and comparedto traditional prognostic markers. These genes can be characterized as oncogenes, tumor suppressor genes or genes for other significant cellfunctions. However, studies are often limited by heterogenity and multifocality of tumors, especially in prostate cancer. In this review, we offera survey of some of the most frequent diagnostic and prognostic parameters of molecular biology research in relation to prostatic carcinoma. Key Words: prostate cancer – molecular biology – molecular markers SuhrnUloha molekularnej biologie pri diagnostike a monitoringu karcinomu prostaty Studium molekulových markerov v roznych neoplaziach ako aj pri karcinome prostaty je založene na analýze genov, ktore sa spolupo dieľaju navzniku karcinomu. Boli sledovane mutacie, amplifikacie a ine zmeny týchto genov alebo ich produktov, ktore su porovnavane s tradicnýmiprognostickými markermi. Tieto geny možno oznaciť ako onkogeny, tumor supresorove geny alebo geny s inými významnými bunkovýmifunkciami. Studie karcinomu prostaty su casto limitovane heterogenitou tohto nadoru. V predloženej praci predkladame prehľad niektorýchnajcastejsich diagnostických a prognostických molekulovo biologických markerov vysetrovaných v suvislosti s karcinomom prostaty.

The role of molecular biology in detection and monitoring of prostate cancer.

Invasive hydatidiform mole is a relative rare form of gestational trophoblastic disease (GTD). Most of hydatidiform moles remit after evacuation but some of them have the tendency to invade the myometrium. In some rare cases the trophoblastic tissue can be found in other tissues like lungs, vulva, vagina or broad ligament. The aim of the study was to demonstrate some of clinical, immunohistochemical and DNA analysis findings of a patient with a previous diagnosis of a complete hydatidiform mole.

Repiska

Papers

The value of SHOX2 methylation test in peripheral blood samples used for the differential diagnosis of lung cancer and other lung disorders.

Molecular analysis of EGFR gene in different types of tumor material from NSCLC patients.

The role of molecular biology in detection and monitoring of prostate cancer.

Mola invasiva--special form of GTD.