Author of

• 13580

  +

  P1.04 - Poster Session/ Biology, Pathology, and Molecular Testing (ID 233)

  • Event: WCLC 2015
  • Type: Poster
  • Track: Biology, Pathology, and Molecular Testing
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/07/2015, 09:30 - 17:00, Exhibit Hall (Hall B+C)

  • 13589

    +

    P1.04-009 - Max Collapse and Fibrosis below 5 cm Predict the Prognosis of pT1 Lepidic Predominant Adenocarcinoma (ID 2605)

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

    Background:
    According to the International Association for the Study of Lung Cancer , American Thoracic Society, and European Respiratory Society (IASLC/ATS/ERS) classification, lepidic predominant pattern in pT1 lung adenocarcinoma is divided into adenocarcinoma in situ　(AIS),　minimally invasive adenocarcinoma (MIA), and lepidic predominant invasive adenocarcinoma (LPIA) by using new diagnostic criteria. However the new criteria have many item to diagnose MIA. So we simply classified the pT1 lepidic predominant adenocarcinoma by using only collapse and fibrosis below 5cm as invasive component, and we evaluated prognosis of MIA.
    
    Methods:
    A total of 231 patients treated for pT1 lepidic predominant lung adenocarcinoma by complete resection at National cancer center hospital east, Chiba, Japan from January 2003 to December 2010 were assessed. We excluded multiple tumor and mucinous invasive adenocarcinoma from the analysis. We classified 187 patients into AIS, MIA, LPIA, according to the IASLC/ATS/ERS classification. The MIA was defined as group A. In the LPIA, we defined invasive component as collapse and fibrosis 5 cm below, and reclassified into MIA and LPIA. Reclassified MIA and LPIA were defined as Group B and C respectively. We analyzed the prognosis of these patients retrospectively.
    
    Results:
    AIS, Group A, Group B, Group C were 52　(22.5%), 29 (12.5%), 39　(16.9), 111 (48.1%) respectively. Positive lymphatic invasion and, or vascular invasion and, or pleural invasion in Group A, Group B, Group C were 0 (0%), 4 (1.2%), 24 (21.6%) respectively. There are significant difference in 5-year recurrence free survival (5y-RFS) between Group A and B (5y-RFS rate 100% versus 88.1%; p = 0.022), and Group A and C (5y-RFS rate 100% versus 88.1%: p = 0.046).
    
    Conclusion:
    Max collapse and fibrosis below 5 cm correlated with the prognosis of pT1 lepidic predominant adenocarcinoma. Max collapse and fibrosis below 5cm is more simpl and easy method to measure invasive component than the new IASLC/ATS/ERS classification. This method may have potential to diagnose MIA instead of the IASLC/ATS/ERS classification.