Virtual Library

Start Your Search

S.C. Tomaszek



Author of

  • +

    MO05 - Prognostic and Predictive Biomarkers II (ID 95)

    • Event: WCLC 2013
    • Type: Mini Oral Abstract Session
    • Track: Medical Oncology
    • Presentations: 1
    • +

      MO05.01 - Validation of gene expression biomarker panels in non-small cell lung cancer (ID 2928)

      16:15 - 17:45  |  Author(s): S.C. Tomaszek

      • Abstract
      • Presentation
      • Slides

      Background
      Many studies in the literature have suggested that gene expression biomarkers may guide patient classification and clinical management in NSCLC. Despite minimal external validation and no clinical trial evidence, gene expression biomarker panels have been proposed as tools for making treatment decisions. Recent controversy surrounding the validity of such data and its potential applicability to clinical practice led us to perform an external validation study of published gene expression biomarker panels.

      Methods
      We performed gene expression profiling for a total of 209 patients with both Affymetrix whole transcriptome U133Plus2 arrays in addition to a NSCLC-specific array constructed by our group for assessment of mRNA expression in frozen tumor specimens of NSCLC. Clinical outcome data were collected and analyzed for correlations of gene expression with disease-free and overall survival. Cox proportional hazard models were used to test significance of individual genes and for gene sets defined by each panel. Panels tested included those previously published from Michigan, Mayo Clinic, Taiwan, Toronto, and UCSF.

      Results
      Expression profiling data were generated for a total of 209 patients with NSCLC. This included U133Plus2 arrays of 242 tumor samples and 105 matched surrounding normal lung tissue, as well as 111 tumor profiles using the NSCLC-specific array. There were 98 women and 111 men in the study cohort, with 120 patients having Stage I NSCLC (57.4%), 38 with Stage II (18.2%), 50 with Stage III (23.9%), and one patient with Stage IV disease (0.5%). Mean follow-up time after surgical resection was 62.4 ± 48 months. Seventy-four patients (35.1%) developed post-resection recurrence after a mean of 53.3 ± 49.3 months, of which 62 patients died (83.8%). Known clinical predictors such as TNM stage, histology, and tumor grade were predictive of survival. Although many genes within the published biomarker panels were significantly correlated with disease-free and overall survival, none provided additive prognostic value beyond standard clinical predictors.

      Conclusion
      Although a number of individual gene expression biomarkers have prognostic significance in univariate models, published biomarker panels perform poorly in external validation studies such as this. The additive prognostic value beyond standard, known clinical predictors in the TNM staging system casts doubt as to whether such information will be useful in clinical practice. Despite the success of gene expression biomarkers for molecular subtyping in other cancers, our data suggests that this information has a low likelihood of clinical translation in NSCLC for unselected patients.

      Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.

  • +

    MO10 - Molecular Pathology II (ID 127)

    • Event: WCLC 2013
    • Type: Mini Oral Abstract Session
    • Track: Pathology
    • Presentations: 1
    • +

      MO10.08 - Genomic alterations in pulmonary carcinoid tumors (ID 3162)

      16:15 - 17:45  |  Author(s): S.C. Tomaszek

      • Abstract
      • Presentation
      • Slides

      Background
      Pulmonary carcinoid tumors account for up to 5% of all lung malignancies in adults and comprise 30% of all carcinoid malignancies. They are defined histologically as typical carcinoid (TC) and atypical carcinoid (AC) tumors, and are characterized by neuroendocrine differentiation and the potential to metastasize. Relatively little is known about bronchopulmonary carcinoid tumorigenesis, and understanding of these tumors has yet to benefit from the insight of genomic studies. This unfortunately has translated into relatively limited treatment options for these patients and no recent advances in therapy. We aimed to characterize genomic alterations in pulmonary carcinoid tumors under the hypothesis that a better molecular understanding may lead to improved therapeutic approaches and patient outcomes.

      Methods
      We characterized genomic alterations in pulmonary carcinoid tumors using whole genome, exome, and RNA sequencing, in addition to mRNA expression and SNP genotyping from specimens of normal lung, typical and atypical carcinoid, and SCLC. Fresh-frozen specimens from 54 patients with primary lung neuroendocrine tumors were obtained from our lung specimen registry and clinical data collected. This included a total of 31 typical and 11 atypical carcinoid tumors with associated normal tissue, and 12 SCLC. Whole transcriptome mRNA expression profiling and SNP genotyping for evaluating copy number variation was performed using Illumina array platforms. For a subset of tumors, whole genome sequencing was performed through Complete Genomics, and exome and RNA sequencing performed through BGI and the Mayo Clinic Genomics Facility. These data were correlated with the histologic subtype, stage and survival data available from this cohort of patients.

      Results
      Gene expression clearly identified distinct profiles differentiating carcinoid tumors from SCLC, though not between typical and atypical carcinoids. Copy number variations (CNV) were widely prevalent in SCLC, less frequent in AC, while TC had the lowest frequency of CNV. Validated sequencing data from exome and WGS platforms revealed a number of novel mutations for pulmonary carcinoid tumors, including ADNP, BRIP1, cyclin B3, CREBL2, GLI3, HERC1, IRAK3, NEDD4L, PRRX2, and ZDBF2, among others. RNA sequencing data did not reveal any novel fusions from analysis to date. Despite a low overall mutation frequency versus other forms of lung cancer, each carcinoid tumor had at least one potential driver mutation, suggesting possible targeted therapy opportunities for a disease where currently none exist.

      Conclusion
      Despite a low overall mutation frequency and an absence of frequently recurring mutations from the tumors sequenced to date, targeted therapy opportunities may exist through mutation profiling in broncopulmonary carcinoid tumors.

      Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.