Emerging therapeutics and evolving assessment criteria for intracranial metastases in patients with oncogene-driven non-small-cell lung cancer.

The improved survival outcomes of patients with non-small-cell lung cancer (NSCLC), largely owing to the improved control of systemic disease provided by immune-checkpoint inhibitors and novel targeted therapies, have highlighted the challenges posed by central nervous system (CNS) metastases as a devastating yet common complication, with up to 50% of patients developing such lesions during the course of the disease. Early-generation tyrosine-kinase inhibitors (TKIs) often provide robust systemic disease control in patients with oncogene-driven NSCLCs, although these agents are usually unable to accumulate to therapeutically relevant concentrations in the CNS owing to an inability to cross the blood-brain barrier. However, the past few years have seen a paradigm shift with the emergence of several novel or later-generation TKIs with improved CNS penetrance. Such agents have promising levels of activity against brain metastases, as demonstrated by data from preclinical and clinical studies. In this Review, we describe current preclinical and clinical evidence of the intracranial activity of TKIs targeting various oncogenic drivers in patients with NSCLC, with a focus on newer agents with enhanced CNS penetration, leptomeningeal disease and the need for intrathecal treatment options. We also discuss evolving assessment criteria and regulatory considerations for future clinical investigations.

Upfront Management of ALK-Rearranged Metastatic Non-small Cell Lung Cancer: One Inhibitor Fits All?

PURPOSE OF REVIEW: Anaplastic lymphoma kinase (ALK) rearrangements represent a seldom event in non-small cell lung cancer (NSCLC). Given the oncogene alteration, ALK targeting represents the main therapeutic strategy. Here, we review evidence regarding ALK inhibitors (ALKi): clinical activity, safety profiles, financial costs, and biomarkers of efficacy. RECENT FINDINGS: During the past 10 years, multiple ALKi have been developed, and four different compounds are currently available as upfront options for ALK+ NSCLC patients: crizotinib, ceritinib, alectinib, and brigatinib. Second-generation (2G) ALKi demonstrated superior clinical activity in terms of median progression-free survival (mPFS), objective response rate (ORR), intracranial disease control, and duration of response (DOR) when compared with crizotinib. 2G ALKi represent the current gold-standard first-line treatment for ALK-rearranged metastatic NSCLC. Among all available options, in our opinion, alectinib has likely the best profile of clinical activity and safety, thus emerging as the best upfront therapy. More insights will come from ongoing trials and analysis of biomarkers.

Molecular testing patterns in metastatic non-small cell lung cancer.

OBJECTIVES: Identification of oncogene mutations and gene rearrangements in individuals with non-small cell lung cancer (NSCLC) can help identify candidates for targeted therapy. This study examined whether clinicians are ordering molecular testing for patients with metastatic NSCLC (mNSCLC) prior to therapy initiation. STUDY DESIGN: Members from a national health plan with lung cancer and metastatic disease were followed retrospectively. METHODS: Members were identified in medical claims data from January 1, 2010, to December 31, 2012, if they had 2 or more claims for lung cancer (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 162.xx) and metastatic disease (≥ 1 claim with ICD-9-CM code 196.xx-198.xx) who were continuously enrolled in a fully insured plan 180 days prior to index date. Patients were excluded if they had a history of chemotherapy used primarily in small cell lung cancer, or a medical claim associated with an unrelated malignancy. The timing of molecular testing was compared with the start of chemotherapy and targeted therapy, if applicable. RESULTS: A total of 2623 patients presumed to have mNSCLC were included for analysis; of whom, 52.5% were male with a mean age of 72.5 years (SD = 8.2 years). A total of 1597 (60.9%) patients had a Current Procedural Terminology code associated with molecular testing at any time in their claims history. Of the 733 patients with molecular testing and chemotherapy or targeted therapy claims, testing occurred prior to systemic therapy initiation in 651 (88.8%; 95% CI, 86.1%-90.9%) patients. The median time between testing and therapy initiation was 38 days (interquartile range = 23-69 days). CONCLUSIONS: Assessment of oncogene mutations and gene rearrangements in mNSCLC routinely occurs prior to treatment initiation as suggested by analyses of claims data from a large US health plan. Validation using patient medical records is needed.

Assessment of gene promoter G­quadruplex binding and modulation by a naphthalene diimide derivative in tumor cells.

Naphthalene diimide (NDI) derivatives have shown high affinity for telomeric guanine (G)­quadruplexes and good antiproliferative activity in different human tumor experimental models. A trisubstituted compound (H­NDI­NMe2) has been reported to stabilize the telomeric G­quadruplex and to cause telomere dysfunction and downregulation of telomerase expression. We further investigated its mechanism of action by analyzing the capability of the molecule to interfere with the expression levels of oncogenes, such as MYC, telome-rase reverse transcriptase (TERT), KIT and BCL2, known to bear G­quadruplex­forming sequences within their promoters, in human tumor cell lines of different histological origin. Exposure to H­NDI­NMe2 resulted in a cell type­dependent perturbation of the expression levels of the four selected genes. Biophysical and molecular analyses revealed that H­NDI­NMe2 bound with high affinity and effectively stabilized mainly MYC and BCL2, which share long sequences and the possibility of multiple G­quadruplex folding. The mRNA levels of both genes, but not protein amounts were affected by NDI treatment. Global gene expression analysis showed modulation of genes implicated in telomere function and mechanisms of cancer; however, G­quadruplex­mediated regulation of gene expression by H­NDI­NMe2 was largely dependent on the cell context. These data indicate that a deeper knowledge on the molecular mechanisms and biological effects of G­quadruplex structures is still needed to help developing new effective anticancer agents.

Integrative analyses for omics data: a Bayesian mixture model to assess the concordance of ChIP-chip and ChIP-seq measurements.

The analysis of different variations in genomics, transcriptomics, epigenomics, and proteomics has increased considerably in recent years. This is especially due to the success of microarray and, more recently, sequencing technology. Apart from understanding mechanisms of disease pathogenesis on a molecular basis, for example in cancer research, the challenge of analyzing such different data types in an integrated way has become increasingly important also for the validation of new sequencing technologies with maximum resolution. For this purpose, a methodological framework for their comparison with microarray techniques in the context of smallest sample sizes, which result from the high costs of experiments, is proposed in this contribution. Based on an adaptation of the externally centered correlation coefficient ( Schäfer et al. 2009 ), it is demonstrated how a Bayesian mixture model can be applied to compare and classify measurements of histone acetylation that stem from chromatin immunoprecipitation combined with either microarray (ChIP-chip) or sequencing techniques (ChIP-seq) for the identification of DNA fragments. Here, the murine hematopoietic cell line 32D, which was transduced with the oncogene BCR-ABL, the hallmark of chronic myeloid leukemia, was characterized. Cells were compared to mock-transduced cells as control. Activation or inhibition of other genes by histone modifications induced by the oncogene is considered critical in such a context for the understanding of the disease.

Heterogeneous subgroups in human neuroblastoma for clinically relevant risk stratification.

Neuroblastoma is a heterogeneous tumor and that may have a favorable or unfavorable prognosis. In Japan, a nation-wide neuroblastoma mass-screening (MS) project assessed 6-month-old infants between 1985 and 2003, and almost all neuroblastomas, including regressing or maturing tumors were thought to be detected in this period. To evaluate the heterogeneity of neuroblastoma subgroups, we analyzed patients with neuroblastoma who had been diagnosed during this period. The clinical courses of 4,209 patients with neuroblastoma, including 1,560 MS detected patients, whose tumors had been diagnosed between 1971 and 1995 were registered. The 2,520 cases registered between 1985 and 1995 were compared to 1,050 cases registered between 1971 and 1980 and analyzed by a multi-gene target model to determine the age distribution of neuroblastoma incidence. We hypothesized that three target genes were responsible for the progression of neuroblastoma: one pair of tumor suppressor gene alleles, one oncogene, and one gene controlling regression/differentiation. This simulation study revealed that the age distribution at initial diagnosis of neuroblastoma was divided into four groups based on post-fertilization age: 20-40, 40-50, 60-90, and 160-200 weeks. Since neuroblatoma in the first group occurred prenatal, post-natal clinical neuroblastoma can be classified into three age groups: 0-6 months, 1-2 years, and 3-4 years. The 0- to 6-month group consisted of mostly benign tumors, and the two older groups had predominantly malignant phenotypes. Our proposed model could explain qualitatively the distribution of neuroblastoma consisting of one subgroup with a favorable prognosis and two subgroups with unfavorable prognosis. For clinically relevant risk stratification, an age cutoff should be considered by the age distribution of these heterogeneous subgroups.

Assessment of differential expression of oncogenes in gastric adenocarcinoma by fluorescent multiplex RT-PCR assay.

We screened samples of tumour and peripheral normal tissue for differential expression of oncogenes by using an approach of detecting the differences in expression of a number of oncogenes simultaneously. Total RNA was isolated from 29 pairs of normal and tumour tissue samples from patients with gastric adenocarcinoma. Seven pairs of primers for oncogenes most probably associated with the process of carcinogenesis in stomach including cyclin E, c-erbB-3, HGR, c-met, TDGF/cripto, FGF-4, and EGF were used for the construction of fluorescent multiplex RT-PCR. Sense primers were 5' end-labelled with a fluorescent dye. 5-7 gastric oncogenes were simultaneously analysed for overexpression. Multiplex reverse transcription with a set of unlabeled primers was followed by a PCR reaction by adding the corresponding set of fluorescent labelled PCR-primers. Expression of oncogenes was compared to GAPDH internal standard. Multiplex fluorescent RT-PCR results were analysed by capillary electrophoresis on ABI-PRISM 310 Genetic Analyzer. Differential expression of oncogene mRNAs in tumour and normal tissue was assessed by comparison of oncogene/GAPDH ratios in tumours and their peripheral normal mucosa. Our results show, that in most patients, comparing to normal tissue, we could estimate overexpression of at least one oncogene in a sample.

Prospects for applying genotypic selection of somatic oncomutation to chemical risk assessment.

Genotypic selection methods detect rare sequence changes in populations of DNA molecules. These methods have been used to investigate the chemical induction of mutation and for the detection and diagnosis of cancer. The possible use of genotypic selection for improving current risk assessment practices is based on the premise that the frequency of somatic mutation is of critical importance in understanding and modeling carcinogenesis. If genotypic selection can measure the induction of specific mutations that disrupt normal cell/tissue homeostasis, then it could provide key mechanistic information for cancer risk assessment. For example, genotypic selection data might support a particular low-dose extrapolation method or characterize the relationship between rodent and human cancer risk. Strategies for evaluating the use of genotypic selection in cancer risk assessment include the concept of developing a battery of targets that detect a range of agent-specific effects. Ideal targets to examine by genotypic selection are the oncogene and tumor suppressor gene mutations frequently detected in human tumors because these are thought to represent tumor-initiating events. The most commonly occurring basepair (bp) substitutions within the ras and p53 genes are identified. Also, the battery of genotypic selection methods is defined in terms of the most important mutational specificities to include. In theory, the major basepair substitution mutations induced by 29 of 31 chemical carcinogens could be detected by analyzing three different mutations: G:C-->T:A, G:C-->A:T, and A:T-->T:A. Genotypic selection will have the greatest impact on risk assessment if measurement of spontaneous mutation is possible. Data from phenotypic selection assays suggest this corresponds to detection of mutant fractions of approximately 10(-7), and this would necessitate examining DNA samples containing >10(7) target molecules. Despite its apparent potential, considerable development and validation is needed before genotypic selection data can be applied to cancer risk assessment.

p53 tumor suppressor gene: at the crossroads of molecular carcinogenesis, molecular epidemiology, and human risk assessment.

The molecular archaeology of the mutation spectra of tumor suppressor genes generates hypotheses concerning the etiology and molecular pathogenesis of human cancer. The spectrum of somatic mutations in the p53 gene implicates environmental carcinogens and both endogenous agents and processes in the etiology of human cancer.

Assessment of mutations of Ha- and Ki-ras oncogenes and the p53 suppressor gene in seven malignant mesothelioma patients exposed to asbestos--PCR-SSCP and sequencing analyses of paraffin-embedded primary tumors.

To examine whether malignant mesothelioma due to asbestos has genetic alterations in the Ha- and Ki-ras oncogenes or in the p53 suppressor gene, we analyzed the point mutations of these genes in paraffin-embedded autopsy samples of the primary tumors of malignant mesothelioma in seven asbestos patients who died from malignant mesothelioma. The genetic analysis was conducted by the polymerase chain reaction-single strand comformation polymorphysms (PCR-SSCP) method in all patients, and through the sequencing of deoxyribonucleic acid (DNA) bases in one patient. No genetic alterations were found in exons 1 or 2 of Ha- and Ki-ras oncogenes, or in exons 5 to 9 of the p53 gene, in any of the patients. Further studies on a larger number of patients are required to reach a definite conclusion concerning the genetic effects of asbestos on malignant mesothelioma.

Common cancers--genetics, origin, prevention, screening: Parts I and II.

Carcinogenesis is a stepwise process that occurs through mutations of cancer-related genes. Five or more genes must be mutated before malignant transformation occurs in most adult cancers; in some childhood cancers as few as two mutated genes may be sufficient. A rare inherited mutation of a critical gene may predestine cancer to occur in one or more sites. This germline mutation is present in virtually every cell in the body, except half of the germ cells, which do not contain the mutated gene in their haploid chromosome set. These and other genes have been used to piece together a puzzle of regulatory systems that govern cell division and proliferation, as well as apoptosis or programmed cell death. Mutations of these genes result not only in increased cell proliferation but also in diminished cell death. Most genetic changes that occur during carcinogenesis are not inherited or germline. They are acquired after birth and are called somatic mutations. A somatic mutation affects only the mutated cell and its progeny. Each time a cell divides, there is a chance of somatic mutation, and therefore there always is a low, background risk for cancer and other malignant lesions. A far more prevalent cause of cancer-related death in the United States is environmental exposure. Such exposure causes somatic mutations of cancer-related genes through direct damage to DNA or through alteration of proliferation or cell death, which enhances the baseline risk for mutation. As carcinogenesis becomes understood, interventions may be designed that selectively interfere in important steps. Screening for cancer is based on the premise that one can treat a patient for a cancer that has not spread from its primary site. Nevertheless, cancer screening is controversial and often confusing. Issues of costs, risks versus benefits, physical time and effort, and patient compliance all affect the clinician's view of screening, often to the extent that the true value of this approach to cancer control is underappreciated and underutilized. A clinician should consider the following questions when assessing the priority, scope, and intensity of cancer screening. Is the cancer an important public health problem? Can preclinical stages be detected and cured? Are effective screening tests available? Are the tests feasible and acceptable? Have screening programs reduced cancer-specific mortality? Is the screening program cost effective? Is screening generally recommended? There is clear-cut evidence of benefit from screening for cancer of the cervix, breast, colon and rectum, and skin and some specific genetic syndromes. Evidence of survival benefit from screening for prostate cancer is lacking, although prostate specific antigen screening is widely used. Screening for lung and ovarian cancer is ineffective.

O envolvimento de genes e proteínas na regulaçäo da apoptose - carcinogênese / The involvement of genes and proteins in apoptosis - carcinogenesis regulation

A apoptose é um fator importante em muitos processos biológicos normais, tais como a embriogênese, o desenvolvimento do sistema imune, a maturaçäo e a diferenciaçäo celular. Em situaçöes patológicas, a apoptose parece estar implicada na imunodeficiência, resistência a drogas e carcinogênese. Sabe-se que a carcinogênese envolve alteraçöes genéticas cumulativas em oncogenes e genes supressores de tumor. Dessa forma, o prognóstico de cada tumor humano parece depender do equilíbrio entre os diversos genes, sendo previsível que um conhecimento mais profundo da cooperaçäo e antagonismo entre esses genes possa fornecer num futuro próximo informaçöes clinicamente relevantes. Nós revisamos alguns dos mais recentes progressos a respeito de genes envolvidos na apoptose e nos cânceres humanos (p53, bcl-2, c-myc, fas-APO-1, mdr-1) e suas implicaçöes clínicas.

A role for the fyn oncogene in metastasis of methylcholanthrene-induced fibrosarcoma A cells.

Expression of various oncogenes (ras, myc, erbB2, src, fyn, yes and sis) in a high-metastatic clone (MH-02) derived from a murine methylcholanthrene-induced fibrosarcoma A (Meth A) was compared with those of its parent clone (ML-01) by Northern blot analysis. Two oncogenes, fyn, belonging to the tyrosine-kinase family, and sis, belonging to the cellular-growth-factor family, were found to have higher signals (3.6-fold and 1.8-fold respectively) in MH-02 than in ML-01 cells. To explore the possibility that higher expression of these oncogenes is involved in enhanced metastasis of the MH-02 clone, ML-01 was transfected by a fyn vector and the metastatic potential of the transfectant was examined. Mice administered fyn-transfected ML-01 cells had significantly increased metastatic nodules in the lung, as compared with those whose ML-01 cells were transfected with control vector without the fyn gene. The result indicates that the fyn gene is one of the factors governing the metastatic potential of Meth A cells.

Biology of cancer: current issues and future prospects.

The future of cancer treatment is limited only by the rate of progress made in understanding the biology of cancer. The future will present a considerable challenge to health care professionals to learn new theories, understand new terms, and expect different toxicities. The explosion of information and technology is exciting, yet frightening. The willingness of scientists, health care professionals, and consumers to deal with the ethical, financial, and political issues generated by this progress is gratifying. Because science has created such advances, the effort to deal with the outcomes is worthwhile but still difficult. The challenge to rapidly facilitate the sharing of the scientific and clinical advances has been recognized by the nation. A legislative mandate to create a way to store and analyze the vast data related to molecular biology, biochemistry, and genetics resulted in the National Center for Biotechnology Information. The development of automated systems to analyze genetic, environmental, biological, and chemistry information can only enhance future progress in the management of cancer.