Author of

• 11745

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  P2.11 - Poster Session 2 - NSCLC Novel Therapies (ID 209)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Medical Oncology
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/29/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 11770

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    P2.11-025 - Erlotinib versus Radiation Therapy for Brain Metastases in Patients with EGFR-Mutant Lung Adenocarcinoma (ID 1904)

    09:30 - 09:30  |  Author(s): K. Beal
    • Abstract

    Background
    Radiation therapy (RT) is a principal modality in the treatment of patients with brain metastases (BM). However, given the activity of EGFR tyrosine kinase inhibitors (EGFR-TKIs) in the central nervous system, it is uncertain whether upfront brain RT is necessary for EGFR mutated lung adenocarcinoma patients with BM treated with EGFR-TKIs.

    Methods
    We identified all patients treated from 2006-2012 with EGFR-mutated NSCLC with BM at our institution. We evaluated the clinical outcomes of these patients who developed brain metastases and received EGFR-TKI and/or CNS radiotherapy. Endpoints included intracranial progression (ICP), extracranial progression (ECP) and overall survival (OS). All endpoints were measured from development of BM.

    Results
    222 patients were identified. Patients were excluded if they were on an EGFR-TKI prior to the development of BM (n=57), if they possessed a de novo EGFR-TKI resistance mutation (n=6), or if there was incomplete data (n=48). Of the remaining 111 patients, 64 were treated initially with erlotinib, 32 with whole brain RT (WBRT), and 15 with partial brain radiation (PBI). Median follow-up was 20 months (mos). Median age was 61 years (range 26-89). Patients were predominantly female (68%), stage IV at diagnosis (92%), never-smokers (61%), RPA class II (87%), and neurologically asymptomatic (82%). Patients had a median of 4 BM (range 1-30) with a median largest diameter of 10mm. In the erlotinib group, erlotinib was given as monotherapy in 91% and combined with chemotherapy in 9% of patients. 38% of these patients (n=24) eventually received WBRT or PBI a median of 17 mos after diagnosis of BM (range 5-40 mos). Median OS for the whole cohort was 29 mos with a 2-yr OS of 59%. There was no significant difference in OS between the WBRT (median 35 mos) and erlotinib (median 26 mos) groups (p=0.59 by Cox model) though patients treated with PBI had a longer OS (median 64 mos). On univariate analysis, KPS (p<.001), RPA class (p<.001) and PBI (vs. erlotinib, p=.005) were significant, with only RPA class (p=.007) and KPS (p<.001) remaining significant on multivariate analysis. Median time to intracranial progression (ICP) was 17 months for the entire cohort. There was a longer time to ICP in patients who received WBRT (median 24 mos) vs. erlotinib upfront (median 16 mos, p<.05), though this effect was no longer significant on multivariate analysis. Patients in the erlotinib or PBI group were more likely to fail intra-cranially as a component of first failure (58% and 71%, respectively), while upfront WBRT patients were more likely to fail extracranially first (76%).

    Conclusion
    The survival of EGFR-TKI naïve patients with EGFR-mutated NSCLC with BM is notably long, whether they receive upfront erlotinib or brain RT. We observed longer intracranial control with WBRT, but this effect is potentially due to other confounding variables. Though retrospective, this analysis suggests that deferring brain RT in favor of EGFR-TKI is a reasonable strategy for patients with EGFR-mutated NSCLC with BM.