Author of

• 25955

  +

  P3.01 - Advanced NSCLC (Not CME Accredited Session) (ID 967)

  • Event: WCLC 2018
  • Type: Poster Viewing in the Exhibit Hall
  • Track:
  • Presentations: 1
  • Moderators:
  • Coordinates: 9/26/2018, 12:00 - 13:30, Exhibit Hall

  • 27357

    +

    P3.01-06 - Concomitant Plasma-Genotyped T790M Positivity and Small Cell Carcinoma Transformation in EGFR-Mutated NSCLC (ID 14459)

    12:00 - 13:30  |  Presenting Author(s): Sourin Bhuniya
    • Abstract

    Background
    

    Patients of non-small cell lung cancer (NSCLC) having epidermal growth factor receptor (EGFR) gene mutation, initially show clinical response to EGFR Tyrosine-Kinase Inhibitors (TKI), but develop resistance after some months. However, the type and timing of TKI-resistance cannot be predicted as it is highly variable. Transformation to small cell lung cancer (SCLC) at progression during TKI-therapy and simultaneous acquisition of T790M EGFR-mutation is uncommonly reported.

    a9ded1e5ce5d75814730bb4caaf49419 Method
    

    Case report: Our patient is a 51 year-male, with stage IV NSCLC of adenocarcinoma subtype (TTF1 positive by IHC). He was initially treated with six cycles of pemetrexed and carboplatin to which he showed good response and was on regular follow up since September 2015. In the meantime, he was detected to have EGFR exon 21-mutation and was treated with Gefitinib for over two years. Patient was doing well and had complete disappearance of the tumour radiologically. After about 26 months of treatment he again became symptomatic. Repeat Computed tomography showed a lobulated mildly enhancing lesion 4.4 × 3 cm in right upper lobe. There were small nodules over bilateral lung fields and subpleural areas in right lower lobe, likely to be metastatic. Lytic lesions were also detected in dorsal (D2) and cervical (C5) vertebral bodies. Liquid biopsy showed T790M EGFR-mutation. Re-biopsy from right upper lobe showed transformation to neuroendocrine carcinoma (SCLC). Gefitinib was stopped and the patient was started on standard platin based doublet regimen for SCLC for the transformation. Patient has received four cycles of platin based chemotherapy and is doing well.

    4c3880bb027f159e801041b1021e88e8 Result
    

    "Section not applicable"

    8eea62084ca7e541d918e823422bd82e Conclusion
    

    This case report shows the possible underlying relationship between SCLC transformation and the T790M mutation, and that liquid biopsy approach may help overcome the problem of heterogeneity in acquired resistance to EGFR-tyrosine kinase inhibitors. In advanced NSCLC with EGFR-mutation, delayed onset of TKI-resistance can occur during TKI-treatment. Re-biopsies have increased the chance of detecting a T790M mutation and transformation. “Liquid biopsies” may potentially help identify heterogeneous genetic resistance-mechanisms; however, assessment of mechanisms such as SCLC-transformation needs tissue biopsies.

    6f8b794f3246b0c1e1780bb4d4d5dc53