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Matthew B Schabath,1,2 Tapashi B Dalvi,3 Hongyue A Dai,4 Alan L Crim,4 Anita Midha,5 Norah Shire,3 Nicholas T Gimbrone,1 Jill Walker,6 Danielle M Greenawalt,7 David Lawrence,8 James R Rigas,9 Robert Brody,9 Danielle Potter,9 Naveen S Kumar,4 Shane A Huntsman,4 Jhanelle E Gray2 1Department of Cancer Epidemiology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA; 2Department of Thoracic Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA; 3Oncology R&D, AstraZeneca, Gaithersburg, MD, USA; 4M2Gen, Tampa, FL, USA; 5Department of Personalised Healthcare and Biomarkers, AstraZeneca, Cambridge, UK; 6Department of Precision Medicine Oncology, AstraZeneca, Cambridge, UK; 7Department of iMED Oncology Informatics, AstraZeneca, Waltham, MA, USA; 8Department of Global Medicines Development, AstraZeneca, Cambridge, UK; 9Department of Global Medical Affairs Oncology, AstraZeneca, Gaithersburg, MD, USACorrespondence: Matthew B SchabathH. Lee Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USATel +1 813 745 4150Fax +1 813 745 6525Email matthew.schabath@moffitt.orgPurpose: To characterize programmed cell death ligand-1 (PD-L1) expression in relation to survival and gene mutation status in patients with advanced NSCLC. The study also explored the influence of tumor mutational burden (TMB) on PD-L1 expression and patient characteristics.Patients and methods: Adult patients with histologically or cytologically documented Stage IIIB/Stage IV/recurrent/progressive NSCLC, Eastern Cooperative Oncology Group performance status 0 to 3, and >2 lines of prior systemic treatment regimens were included in this retrospective analysis. Patients were treated from 1997 to 2015 at H. Lee Moffitt Cancer Center and Research Institute, Tampa, or at 7 community centers across the United States. PD-L1 expression level was determined using the VENTANA PD-L1 (SP263) Assay. EGFR and KRAS mutation status and ALK rearrangements were determined by targeted DNA sequencing; these were obtained from clinical records where targeted DNA sequencing was not performed. TMB was calculated as the total number of somatic mutations per sample.Results: From a total of 136 patients included in the study, 23.5% had tumors with high PD-L1 expression (≥25%). There were no significant differences in patient characteristics, overall survival (OS), and progression-free survival (PFS) between patients with high PD-L1 expression (median OS: 39.5 months; median PFS: 15.8 months) vs low PD-L1 expression (

Endosialin (CD248, TEM-1) is expressed in pericytes, tumor vasculature, tumor fibroblasts, and some tumor cells, including sarcomas, with limited normal tissue expression, and appears to play a key role in tumor-stromal interactions, including angiogenesis. Monoclonal antibodies targeting endosialin have entered clinical trials, including soft tissue sarcomas. We evaluated a cohort of 94 soft tissue sarcoma samples to assess the correlation between gene expression and protein expression by immunohistochemistry for endosialin and PDGFR-β, a reported interacting protein, across available diagnoses. Correlations between the expression of endosialin and 13 other genes of interest were also examined. Within cohorts of soft tissue diagnoses assembled by tissue type (liposarcoma, leiomyosarcoma, undifferentiated sarcoma, and other), endosialin expression was significantly correlated with a better outcome. Endosialin expression was highest in liposarcomas and lowest in leiomyosarcomas. A robust correlation between protein and gene expression data for both endosialin and PDGFR-βwas observed. Endosialin expression positively correlated with PDGFR-βand heparin sulphate proteoglycan 2 and negatively correlated with carbonic anhydrase IX. Endosialin likely interacts with a network of extracellular and hypoxia activated proteins in sarcomas and other tumor types. Since expression does vary across histologic groups, endosialin may represent a selective target in soft tissue sarcomas.

Background CYYR1 is a recently identified gene located on human chromosome 21 whose product has no similarity to any known protein and is of unknown function. Analysis of expressed sequence tags (ESTs) have revealed high human CYYR1 expression in cells belonging to the diffuse neuroendocrine system (DNES). These cells may be the origin of neuroendocrine (NE) tumors. The aim of this study was to conduct an initial analysis of sequence, splicing and expression of the CYYR1 mRNA in human NE tumors. Methods The CYYR1 mRNA coding sequence (CDS) was studied in 32 NE tumors by RT-PCR and sequence analysis. A subtle alternative splicing was identified generating two isoforms of CYYR1 mRNA differing in terms of the absence (CAG- isoform, the first described mRNA for CYYR1 locus) or the presence (CAG+ isoform) of a CAG codon. When present, this specific codon determines the presence of an alanine residue, at the exon 3/exon 4 junction of the CYYR1 mRNA. The two mRNA isoform amounts were determined by quantitative relative RT-PCR in 29 NE tumors, 2 non-neuroendocrine tumors and 10 normal tissues. A bioinformatic analysis was performed to search for the existence of the two CYYR1 isoforms in other species. Results The CYYR1 CDS did not show differences compared to the reference sequence in any of the samples, with the exception of an NE tumor arising in the neck region. Sequence analysis of this tumor identified a change in the CDS 333 position (T instead of C), leading to the amino acid mutation P111S. NE tumor samples showed no significant difference in either CYYR1 CAG- or CAG+ isoform expression compared to control tissues. CYYR1 CAG- isoform was significantly more expressed than CAG+ isoform in NE tumors as well as in control samples investigated. Bioinformatic analysis revealed that only the genomic sequence of Pan troglodytes CYYR1 is consistent with the possible existence of the two described mRNA isoforms. Conclusion A new "subtle" splicing isoform (CAG+) of CYYR1 mRNA, the sequence and the expression of this gene were defined in a large series of NE tumors.

e22167 Background: Ovarian cancer is a histologically and molecularly heterogeneous disease that has a clear need for prognostic and predictive tests to improve treatment and outcomes. The TCC prot...

e15017 Background: Molecular-based pt assessment is commonly used to identify proper candidates for targeted therapies. The objective of our investigation was to examine the utility of the Total Ca...

470 Background: Sunitinib is a standard of care for advanced RCC. Despite efforts to identify predictive molecular markers for patient selection, none are available, likely due to multiple resistance mechanisms. Using the Total Cancer Care (TCC) database, which integrates patient clinical, molecular, and biospecimen data, we devised a tumor genomics and transcriptomics experiment to identify differences between RCC patients who derive prolonged clinical benefit from sunitinib versus those who are resistant. Methods: A discovery set of 34 RCC patients treated with sunitinib at the approved regimen were identified in the TCC database (n=16 treated for ≤6 months, having primarily discontinued for reasons other than tolerability; n=18 treated for ≥18 months). Tumor samples were analyzed by whole exome sequencing (WES) and by parallel 400-gene expression profiling. Following gene mutation identification and supervised gene expression analysis, molecular differences between the two groups were identified and tested for potential association with treatment duration. Results: Of the 34 cases identified, 24 remained for analysis following sample QC failure and clinical review (n=10 and 14 treated for ≤6 and ≥18 months, respectively). Gene expression analysis revealed a 37-gene signature associated with treatment duration: MAPK8 (JNK1) was a leading candidate biomarker (Pearson correlation with log [treatment duration]=–0.70; p=0.06 after Bonferroni multiplicity correction). Pathway-based WES analyses identified 25 potential variants of interest, none remaining statistically significant after correction. However, following genome-wide analysis, a single variant in an intronic region of ING3 was statistically associated with treatment duration (p=0.02). Conclusions: Activation of the PI3K/AKT pathway was a marker of resistance to sunitinib. In contrast, activation of the angiogenic, NOTCH, or JAK-STAT pathways was, to some degree, associated with sensitivity to therapy. However, neither VHL alteration nor lack of expression, nor alteration in chromatin-rearrangement genes, was associated with sunitinib treatment duration. These findings require further validation in a larger and independent cohort.

The activation of the insulin-like growth factor 1/IGF1 receptor system (IGF1/IGF1R) is a critical event in the transformation and tumorigenicity processes in a wide variety of human tumors. The IGF1/IGF1R system has been recently studied in carcinoid tumors that often arise in the gastrointestinal tract; these tumors are characterized by hypersecretion of bioamines and neuropeptides, leading to functional tumor disease. Two alternatively spliced IGF1R mRNA transcripts have been described to differ by only three nucleotides (CAG) in the coding sequence, resulting in an amino-acid change from the originally described Thr-Gly to an Arg in the extracellular portion of the receptor beta subunit. In transfected Chinese hamster ovary cells, the form without CAG (CAG-) exhibited an approximate 2-fold increase in IGF1 stimulation of activities required for its mitogenic properties. In this study, we examine the relative expression of the two IGF1R mRNA isoforms by a semiquantitative RT-PCR approach using highly standardized conditions, beta-2 microglobulin (B2M) as a reference gene and gel imaging analysis. We analyzed a large series of human neuroendocrine tumors (32 samples) and 9 normal tissues. A significant higher expression of both isoforms in the tumor samples (approximately 2-fold increase) was found, while a constant CAG+/CAG- IGF1R mRNA isoforms of an approximate 3:1 ratio was observed in all tumoral and normal cell types studied. The phylogenetic study of the IGF1R locus in several species suggests that human IGF1R CAG- mRNA isoform is evolutionarily more recent compared to the IGF1R CAG+ mRNA isoform and it could be used by the splicing apparatus at this intron/exon junction with a lower efficiency. This study highlights the relevance of IGF1R mRNA expression in neuroendocrine tumor cells, and the constant presence of 'subtle' alternative splicing for the IGF1R locus.

BACKGROUND Gene expression profiling using gene-discovery, high-density microarray technologies is a powerful tool. One potential application is the development of tumor classifiers that predict the site of origin. For this technology to be relevant, however, it must be applicable to tumor biopsy samples, which most often are fine-needle aspiration biopsy (FNAB) samples. METHODS Surgically resected tumors were sampled by FNAB using different gauge needles. A portion of the excised tumor was also collected. RNA samples were extracted using standard techniques and the quality and quantity of the RNA samples were measured for each sample. Thirteen representative FNAB samples and two representative tissue samples were submitted for microarray analysis and then subjected to a tumor classifier. RESULTS Fourteen of 18 samples analyzed for quantity and quality of RNA yielded an adequate amount of RNA (> 1 μg total RNA). Tumor type contributed to the RNA yield because one of the four inadequate samples was retrieved from a patient with lobular carcinoma of the breast and the other three samples were retrieved from patients with retroperitoneal sarcomas. Of the 13 samples submitted for microarray analysis, 9 were classified correctly as to tumor type using a tissue-based tumor classifier. CONCLUSIONS The authors demonstrated that FNABs reproducibly obtained an adequate amount of RNA for microarray analysis when a standardized collection procedure was used. Furthermore, the samples generated interpretable gene expression profiles that could be matched accurately with a tumor classifier established on tissue specimens. The current study showed that FNAB produced adequate material for microarray analysis when utilizing a standardized collection procedure. Cancer (Cancer Cytopathol) 2005. © 2005 American Cancer Society.