Author of

• 15382

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  P3.04 - Poster Session/ Biology, Pathology, and Molecular Testing (ID 235)

  • Event: WCLC 2015
  • Type: Poster
  • Track: Biology, Pathology, and Molecular Testing
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/09/2015, 09:30 - 17:00, Exhibit Hall (Hall B+C)

  • 15419

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    P3.04-037 - Prevalence of NRG1 Fusions in Caucasian NSCLC Patients Determined by Fluorescence in Situ Hybridisation (ID 1553)

    09:30 - 09:30  |  Author(s): H. Schildhaus
    • Abstract

    Background:
    Fusions of the gene Neuregulin1 (NRG1) have been described to activate PI3K-AKT signaling in NSCLC via NRG1 overexpression and binding to Her2/Neu-Her3. NRG1 fusions were detected in pulmonary mucinous adenocarcinoma of Asian non-smokers lacking other known oncogenic driver mutations. The incidence in such patients has been described to be between 17.6% (6/34) and 44.4% (4/9). NRG1 fusions might be targeted by Her2/Her3-inhibitors and clinical trials are planned. Here we describe for the first time the systematic analysis of NRG1 in Caucasian patients by Fluorescence in situ hybridization (FISH).
    
    Methods:
    A ZytoLight®-based FISH assay (ZytoVision, Bremerhaven, Germany) was developed and verified on nine published clinical cases with known NRG1 fusions. A total of 160 Caucasian NSCLC patients were screened. 25 of the cases were mucinous adenocarcinoma lacking a known oncogenic driver mutation as determined by deep-sequencing and FISH tests. 135 cases were pulmonary adenocarcinoma of various subtypes including 35 cases that lacked a driver mutation and 100 cases that were EGFR, ALK and ROS1 wildtype. The smoking-status was not evaluated. Statistics were calculated using R 3.1.0 .
    
    Results:
    The NRG1 fusions in the published cases were easily detected by the FISH assay. However, none of the screened cases harbored a NRG1 fusion. The result is significant compared to published reference values of 17.6% (p=0.041) and 44.4% (p<0.001). The theoretical maximum incidence of NRG1 fusions among Caucasian NSCLC patients not stratified by smoking-status was calculated to be <16.6% for mucinous adenocarcinomas lacking driver mutations, <7.5% for adenocarcinoma of all morphological subtypes lacking driver mutations and <3% for EGFR, ALK, ROS1 negative pulmonary adenocarcinoma (95% confidence intervals).
    
    Conclusion:
    FISH is a suitable technique to screen for NRG1 fusions in pulmonary adenocarcinoma. Among 160 Caucasian patients including 25 mucinous carcinomas lacking a driver mutation none were NRG1 positive. Thus, the incidence among Caucasian patients appears to be low and should be evaluated in studies of large NSCLC cohorts.