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Introduction. Rhabdomyosarcoma (RMS) accounts for 5% of all pediatric cancer and is the most prevalent soft tissue tumor in childhood and adolescents. RMS is thought to arise from primitive mesenchymal stem cells directed towards myogenesis. Between 7-33% of RMS cases arise from a hereditary cancer syndrome, like LFS or NF1. We analyzed germline genetic variants in hereditary cancer genes in 122 children with RMS. Methodology. In 122 children with RMS and 1001 cancer-free adults, we examined germline exome data to determine the frequency of genetic variants in 51 cancer genes known to underlie syndromes associated with RMS. DNA was extracted from blood or buccal cells using standard methods. Exome enrichment was performed with NimbleGen SeqCap EZ Human Exome Library v3.0+UTR, on an Illumina HiSeq. Annotation of each exome variant was performed using a custom software pipeline. We evaluated all variants that passed quality controls with a population minor allele frequency (MAF) Results We compared the age, gender, histologic type and localization of the primary RMS of the patients with and without P/LP variants in the 51 genes. In the patients without P/LP variants, the mean age of diagnosis was 5 years and the most frequent site of diagnosis was head and neck. In the group with P/LP variants, the mean age of diagnosis was 10 years, and the most frequent site was pelvis. In the 51 genes that were analyzed we found 9 P and 12 LP variants in 15 genes: TP53, ATM, MSH6, PMS, DICER1, FANCA, RECQL4, PTEN, WRN, RB1, BUB1B, RET, APC, FANCM and TSC2; genes with 2 variants include WRN, PTEN, BUB1B, FANCA and RET. Most of the variations were stopgain, follow by missense, frameshift insertion and splicing genetic variations. Ten of this genes are associated with an autosomal dominant pattern of inheritance. In one 15-year-old female patient with an alveolar RMS in the paraspinal area we found P/LP variants in PTEN and PMS2. The frequency of P/LP variants in cases was 16% and 3% in controls. Conclusions. To our knowledge, this is the first study where multiple germline variation where analyses in children with RMS. We found P/LP variation in 16% of all the cases (pending orthogonal confirmation); the mean age of diagnosis was 10 years old and their primary tumor site was in the pelvis (50%). Identification of P/LP variation in genes underlying RMS-associated syndromes has implications for follow-up, screening and management of these patients and their families. We acknowledge the Children’s Oncology Group in helping to assemble the RMS cohort. Citation Format: Talia Wegman-Ostrosky, Rajesh Patidar, Sivasish Sindiri, Jack Shern, Douglas S. Hawkins, Daniel Catchpoole, Jun S. Wei, Stephen Skapek, Javed Khan, Douglas R. Stewart. Exome analysis of known hereditary cancer genes in 122 children with rhabdomyosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3003. doi:10.1158/1538-7445.AM2017-3003

Introduction: Astrocytomas are the most common and lethal brain tumors with a median survival of 15 months. Different biomarkers have arisen to classify and treat this type of tumors; one of these markers is MGMT. The methylation status of this gene is a prognostic and predictive factor. The MGMT (O-6-Methylguanine-DNA Methyltransferase) is involved in the cellular response to the effects of O6-methylguanine (O6-MeG) in DNA. Repairs alkylated guanine in DNA by transferring the alkyl group at the O-6 position to a cysteine residue in the enzyme. The dysregulation of this methylation is critical in the development of certain cancers. Objective: To identify germinal MGMT gene variations in patients with astrocytoma. Material and methods: 55 randomly selected Mexican patients diagnosed with astrocytoma between 2008-2014 were consented to perform the molecular analysis of the whole gene and 5´UTR and 3´UTR regions of MGMT at Ion Torrent platform. Each amplified region had a depth of minimum 1500x. Ion Reporter software was used to analyze the genetic variants and using Integrative Genomic Viewer we confirmed that each variant had a Phred higher than 25. Genotypic frequencies were compared with HapMapMex and Mexican ancestry population from the 1000 Genomes project. Results. In lymphocytes DNA, eight genetic variants were found, and two of them were statistically significant risk factors: rs7896488 alternative allele A with a frequency of 15% in patients with astrocytoma, and only 4% of the control group (OR=5.53, IC 1.96-15.59 p = 0.0007) and rs2308326 ancestral allele C, where 93% of the patients were carriers of allele C in contrast with 73% of controls (OR=5.39, IC 2.29-12.69 p = 0.000019). These variants are non-coding single nucleotide polymorphisms, rs7896488 is a 3' UTR genetic variant, while rs2308326 is an intronic variant. Conclusion: Our study found two new risk SNV for Astrocytoma in a Mexican population. Citation Format: Liliana Gomez-Flores-Ramos, Talia Wegman-Ostrosky. Novel MGMT variant association in Mexican patients with astrocytoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3414. doi:10.1158/1538-7445.AM2017-3414

Introduction: Malignant tumors of the central nervous system contribute extremely to cancer mortality especially in the high risk age groups. In USA are the second and the fifth leading cause of cancer mortality in men and women aged 20 to 39 years respectively. Astrocytomas are the most common and lethal tumors of the CNS, being the most common grade IV (glioblastoma) (4.37 per 100,000 population). The prognosis of astrocytomas can be predicted by specific clinical factors allowing neurosurgeons and neuro-oncologists to define the best treatment for each patient. Some patients’ features like age, gender, performance status and tumor localization have been studied as potential prognostic factors. In Mexico there are few reports on demographic, clinical characteristics and prognostic factors in adults. Objective: To explore the clinical prognostic factors for adults affected with astrocytoma Methods: Using a historic cohort, we selected by simple randomization, 155 clinical files from patients with astrocytoma. The main outcome variable was overall survival time (OS). To identify clinical prognosis factors we used: bivariate analysis, Cox regression models, log rank test and Kaplan-Meier survival function. Results: The mean age at diagnosis was 45.7 years. Compared with other studies, our population was 15 years younger when diagnosed. Analysis by stage in grade II, III and IV also showed a younger age of presentation. The OS was 15 months, 9% (n = 14) presented a survival of 2 years and 3% of 3 years. Kaplan-Meier survival estimate showed that the variables grade, Karnofsky Performance Status (KPS)>70, the type of resection, chemotherapy, radiotherapy, alcohol consumption, familiar history of cancer and clinical presentation were significantly associated to survival time. Using proportional Hazard Model the variables: age, grade IV, resection, chemotherapy + radiotherapy and KPS where prognosis factors. Conclusion: Astrocytoma in our study was present in young adults. The OS was 15 months, 9% (n = 14) presented a survival of 2 years and 3% of 3 years. The variables alcoholism, family history of cancer and clinical presentation influenced significantly survival time, and showed a tendency in the mortality analyses. Citation Format: Talia Wegman-Ostrosky, Nancy Reynoso Noverón, Sonia Iliana Mejía-Pérez, Thalía Estefania Sánchez-Correa MD, Rosa María Álvarez, Bernardo Cacho, Luis A. Montalvo, Teresita Corona. Clinical prognostic factors in adult with astrocytoma: Historic cohort. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3420.

Background: Astrocytomas are the most common and lethal brain tumors. The median survival of patients is 15 months. The study of genetic alterations may help to understand the mechanisms of development and behavior of the disease and thus understand the risk factors and prognostic factors. AGT gene and its peptide derivatives, are involved in cell proliferation and neoangiogenesis and resistance to apoptosis, hence the pathogenesis of astrocytomas. Objective: To identify somatic and germinal AGT gene variations in from patients with astrocytoma. Material and methods: 155 randomly selected files from patients diagnosed with astrocytoma between 2008-2014 were revised to determined clinical prognosis factor in Mexican population. In 25 patients, the molecular analysis of the whole codification region, 5´UTR and 3´UTR of the gene AGT was done in tumors biopsy and blood. Each amplified region had a depth of minimum 1500x. IonReporter software was utilize to analyze the genetic variants and using Integrative Genomic Viewer we confirmed that each variant had a Phred higher than 25. Genotypic frequencies were compared with HapMapMex. Results The clinical variants associated with prognosis were age (OR 0.01 IC 95% 1.02-1.07, p = 0.000), Grade IV (OR 17.11, IC 95% 1.89-132.13 p = 0.011), location of tumor (OR 1.17, IC 1.2-6.3, p = 0.016), total resection (OR = .186, IC 95% .098-.622, p = 0.003, Karnofsky (OR = .05, IC 95% 0.024-0.24, p = 0.003), motor deficiency (OR = 3.5, IC = 1.1-10.5, p = 0.025). In blood were found 11 genetic variants. rs4049, rs2148582, rs699, rs4762 and rs1926723 were associated with risk of tumor in the codominant model. rs5050 (- A20C) was statistically associated with the prognosis (OR 10.8, IC 1.16-100.51 p = 0.036). These variant it is part of a haplotype related to low expression of angiotensinogen. In biopsies of 2 patients missense mutations were found p.Arg477His in one patient and Gly226Ala -Pro165Ser in another one. Conclusion: In 8% of the tumors samples new somatic mutations were found. The genetic variant rs5050 of AGT is a prognosis biomarker in patients with astrocytoma. Citation Format: Talia Wegman-Ostrosky, Ernesto Soto-Reyes, Silvia Vidal-Millan, Sonia Mejia, José Sánchez-Corona, Luis A. Herrera. AGT mutations as a prognosis factor in patients with astrocytoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 594. doi:10.1158/1538-7445.AM2015-594