Author of

• 10801

  +

  P1.11 - Poster Session 1 - NSCLC Novel Therapies (ID 208)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Medical Oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10838

    +

    P1.11-038 - The significance of ALK rearrangement in selected advanced non-small cell lung cancer: ALK expression provides insights into ALK target therapy (ID 2757)

    09:30 - 09:30  |  Author(s): Z. Yuan
    • Abstract

    Background
    ALK rearrangements are detected in 3%~7% in unselected non-small cell lung cancer (NSCLC) and accurate determination of ALK rearrangements are the key importance to screen appropriate candidates for ALK inhibitor therapy. Previous studies showed that IHC could be a promising prescreening method. However, the correlation between IHC results and clinical outcomes had not been confirmed. This study aimed to elucidate clinical significance of ALK rearrangement in selected advanced NSCLC patients and evaluate a possible association between ALK expression and clinical outcomes in ALK positive crizotinib-treated patients.

    Methods
    ALK status was assessed by FISH, immunohistochemistry (IHC) and quantitative RT-PCR(qRT-PCR) in 173 selected advanced NSCLC patients who were aiming at undergoing ALK screening for crizotinib therapy. Clinicopathologic data, genotype status and survival outcomes were analyzed. In addtion, we correlated ALK expression with clinical outcomes in crizotinb treated patients including two patients with concurrent ALK rearrangement and EGFR mutation.

    Results
    ALK positive detection rate was 35.5% (59/166), 36.3% (61/168), 27.9% (34/122) by FISH, IHC and qRT-PCR, respectively. Among the 166 advanced NSCLC patients who were successfully underwent ALK screening by FISH, 20 patients with EGFR mutation, 87 patients with wild type status and 2 (3.4%, 2/59) patients with concurrent ALK rearrangement and EGFR mutation. Of the 59 patients with FISH-positive ALK rearrangement, 45 received crizotinib in the phase II clinical trial (PROFILE 1005), 8 were enrolled in the phase III clinical trial (PROFILE 1014) and 6 did not participate in any clinical trial. ALK-positive patients have distinct clinicopathological features. ALK FISH-positive and crizotinib-treated patients (PROFILE 1005) had a median progression-free survival (PFS) of 7.6 months and longer overall survival (OS) compared with crizotinib-naïve (P<0.0001) or wild type cohorts (P=0.0138), but there was no significant difference in OS compared with EGFR mutation patients(P=0.8959). ALK positive and negative patients divided by qRT-PCR in the ALK FISH crizotinib-treated patients had no different in clinical outcomes. ALK expression was not associated with PFS (P=0.792) and OS (P=0.325). However, when used IHC expression as a dichotomous variable, moderate and strong ALK expression had a decreased risk of death (P=0.026). The two patients with concurrent EGFR mutation and ALK rearrangement had difference in ALK expression, response to TKIs and crizotinib, and overall survival.

    Conclusion
    In the era of ALK-targeted inhibitors, enriching NSCLC patients according to clinicopathologic characteristics could highly improve ALK detection rate for molecular target therapy. IHC could be a supplementary method to provide more clues for clinical trial design and therapeutic strategies for NSCLC patients who harbor ALK rearrangement including patients with double genetic aberration of ALK and EGFR.