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

  • 11774

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    P2.11-029 - EGFR-mutations and resulting treatment in a NSCLC population-based cohort in Central Sweden (ID 2200)

    09:30 - 09:30  |  Author(s): A. Berglund
    • Abstract

    Background
    Since the IPASS-study was published in 2009, EGFR-TKI has been the recommended first line treatment for EGFR-mutation positive (EGFR-m[+]) non-small cell lung cancer (NSCLC) patients. In Sweden, the indication for EGFR-mutation testing of NSCLC, based on national and regional consensus guidelines, has gradually shifted from clinical characteristics (age, sex and smoking status) to histological subtypes (non-squamous cell lung cancer). The aim of this study was to characterise the EGFR-mutation spectrum in a representative Swedish NSCLC cohort in relation to patient demographics, histology, prognosis and sample quality parameters. We also wanted to assess the adherence to guidelines regarding molecular testing and treatment recommendations.

    Methods
    NSCLC patients tested for EGFR mutations 2010-2012 (n=669) were identified in records at the molecular pathology unit in Uppsala that serves five regional hospitals in central Sweden. Histopathology and molecular reports were reviewed, and age, sex, stage, smoking, performance status and overall survival data were retrieved from regional and national lung cancer registries. For the EGFR-mutated sub-group a medical chart follow-up was performed to evaluate TKI-treatment and chemotherapy response. In addition, for estimation of potential clinical selection bias and true molecular testing coverage, we compared the study cohort, referred for EGFR-analysis, to the entire source NSCLC population (n=2527) in the five covered counties.

    Results
    The EGFR-tested cohort consisted of 83% adenocarcinomas (AdC), 5% squamous cell carcinomas (SqCC), 11% large cell carcinomas not otherwise specified (LC) and 1% where histology was not reported. The EGFR mutation frequency was 10% (n=66), with an expected frequency distribution within exons 18-21. Mutations were enriched in women, never smokers and AdC. The analysed tissue was collected using bronchoscopic px (29%), core needle biopsy (46%), cytology (1%), and surgical specimens (22%), with mean tumor cell fraction of 30% (range 5–85%). With regard to the subgroup in focus for TKI-treatment, i.e. patients in stage IIIb/IV with non-squamous histology, 36% were referred for EGFR-testing, with an increasing trend between 2010 and 2012 (27.9–40.1%). Of the patients with EGFR-m[+] and advanced disease 38% received EGFR-TKI in first line, 46% in later lines and 16% had not received EGFR-TKI at time of follow up. There was a trend for worse overall survival in the subgroup not receiving TKI-treatment, however this difference did not reach statistical significance.

    Conclusion
    The results regarding the EGFR mutation frequency and patient demographics is similar to previously published data on western populations. Surprisingly, despite guidelines regarding molecular testing, the majority of patients in advanced stage with non-squamous histology were not referred for EGFR-analysis and only a minority of the EGFR-m[+] patients received TKI-treatment in first line. Our results highlight the need for follow-up of treatment and diagnostic algorithms in population-based real life patient cohorts combining quality registries, pathology review and clinical records.