Author of

• 18272

  +

  P3.01 - Poster Session with Presenters Present (ID 469)

  • Event: WCLC 2016
  • Type: Poster Presenters Present
  • Track: Biology/Pathology
  • Presentations: 1
  • Moderators:
  • Coordinates: 12/07/2016, 14:30 - 15:45, Hall B (Poster Area)

  • 18289

    +

    P3.01-017 - Primary Lung Adenocarcinomas with Enteric Differentiation: A Retrospective Analysis (ID 5024)

    14:30 - 14:30  |  Author(s): P. Conte
    • Abstract

    Background:
    Primary lung enteric adenocarcinoma is a rare histologic type sharing morphologic features with colorectal adenocarcinoma. Few reports are described in literature, and no specific indications are available to address treatment.
    
    Methods:
    We retrospectively collected primary lung adenocarcinomas defined as enteric according to the 2011 International Association for the Study of Lung Cancer classification and analyzed clinical, immunohistochemical and molecular data. Immunohistochemistry (IHC) for CDX2, CK20, CK7 and TTF1 were performed and EGFR, RAS and ALK status was determined as standard procedures.
    
    Results:
    The series included 18 patients diagnosed and treated at our Institution between 2012 and 2015. Gastrointestinal primitive lesions were excluded using [18]FDG-CT-PET and endoscopic examination. Median age was 60.5 years, patients were predominantly males (M:F 12:6). More than a half of patients (56%) were never or former smokers. IHC characterization identified 14 cases expressing at least one intestinal differentiation marker (CDX2 and/or CK20), while TTF1 was expressed in five cases. At time of diagnosis, 15 cases (83%) were stage IV, while 3 patients were stage II and underwent systemic progression within one year from radical surgery. Most frequent metastatic sites were bone (44%), adrenal gland (32%) and pleura (28%). Exon 18-19-20-21 EGFR mutations were assessed in 15 patients, resulting in 3 (20%) rare mutations (exon 19 I745insKIPVAI; exon 18 G719A; exon 20 S768R) and no common sensitizing EGFR mutations. No RAS or ALK alterations were found. For metastatic disease, 15 patients were able to receive first-line treatment: 12 patients received platinum-based doublet (with the addition of bevacizumab in two cases), one capecitabine (n: 1), two patients received EGFR inhibitors. Eight patients were able to receive second-line systemic treatment and one patient was treated with fluoruracil, oxaliplatin and bevacixumab. Three patients obtained radiological response following chemotherapy and two of them received fluoropyrimidine. Median overall survival from metastatic diagnosis was 10 (95%CI: 8-NA) months and median progression-free survival was 6 (95% CI: 2-NA) months, but great heterogeneity in outcome was noticed and three EGFR, RAS wild-type patients live more than 30 months from diagnosis of metastatic disease. The presence of rare EGFR mutations was associated with no smoking history and worse outcome; best radiological response to EGFR inhibitors was progression.
    
    Conclusion:
    Primary lung enteric adenocarcinoma has heterogeneous clinical behavior and is mainly refractory to standard chemotherapy. It presents specific epidemiological features and deeper genetic characterization is ongoing to define different subgroups and try to improve therapeutic approach.