Author of

• 12791

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  P3.19 - Poster Session 3 - Imaging (ID 181)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Imaging, Staging & Screening
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/30/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 12805

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    P3.19-014 - CT Morphologic Patterns, Pathologic Subtypes, and Genetic Phenotypes: A Correlation Study in 600 Nodular Lung Adenocarcinomas (ID 2094)

    09:30 - 09:30  |  Author(s): M. Kang
    • Abstract

    Background
    Genotype manifests itself as phenotype and that the one may inform the other. In terms of phenotype, imaging has the potential to assist in noninvasively characterizing the tumor, however, there are very few investigators who have pursued that potential connection between imaging features and the genetic characteristics of lung cancer. The purpose of this study was to retrospectively correlate the CT morphologic patterns of nodular lung adenocarcinomas (ADs) with pathological and molecular phenotypes in an East-Asian cohort of patients.

    Methods
    The institutional review board approved this retrospective study, and all patients provided informed consent. 600 primary lung ADs smaller than 3 cm in diameter that were surgically resected from 592 patients (M:F=257:335; mean age, 63) were included. CT morphologic pattern of ADs was evaluated by three board-certified thoracic radiologists and was classified into four patterns: pure GGN, GGO dominant part-solid nodule (PSN), solid dominant PSN, and pure solid nodule. EGFR mutation, ALK rearrangement, and KRAS mutation were evaluated using PCR-based direct DNA sequencing and FISH. Histologic subtype was classified according to IASLC/ATS/ERS classification of lung AD. The Fisher exact test and student t-test were used to assess statistical significance.

    Results
    Figure 1 In terms of CT morphologic patterns, 17.2%,15.2%, 31.8%, and 35.8% of tumors manifested as pure GGN, GGO dominant PSNs, solid dominant PSNs, and pure solid nodules, respectively. EGFR mutation was significantly more often found in ADs that manifested as subsolid nodules (69.9%, 269/385) than in ADs presented as pure solid nodules (46.7%, 100/214) (P<.0001). ALK rearrangement was more frequent in ADs that manifested as pure solid nodule (8.5%, 13/153) than in tumors presented as subsolid nodule (1.8%, 5/281) (P=.001). KRAS mutation showed no significant difference between subsolid nodules (6.6%, 8/121) and pure solid nodules (8.5%, 5/59) (P=.760). The ratio of subsolid nodule vs pure solid nodule was 72.7% vs 27.3% in ADs with EGFR mutation and was 27.8% vs 72.2% in ADs with ALK rearrangement. EGFR mutation was more frequent in minimally invasive ADs (P=.004) and lepidic predominant ADs (P=.018). ALK rearrangement was more frequent in solid predominant ADs (P=.002) and invasive mucinous ADs (P=.030). KRAS mutation was more frequent in invasive mucinous ADs (P=.001).

    Conclusion
    EGFR mutation was significantly more often found in ADs that manifested as subsolid nodules, and ALK rearrangement was more frequent in ADs that manifested as pure solid nodule.