Author of

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  P3.11 - Poster Session 3 - NSCLC Novel Therapies (ID 211)

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

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    P3.11-001 - Classification and regression tree analysis of patients with non-small-cell lung cancer treated with gefitinib after chemotherapy (ID 50)

    09:30 - 09:30  |  Author(s): J. Guo
    • Abstract

    Background
    Many randomized studies have shown that epidermal growth factor receptor (EGFR-) tyrosine kinase inhibitors (TKIs) are apparently advantageous over standard chemotherapy in non-small-cell lung cancer (NSCLC) patients with EGFR active mutation in front-line treatment. But the EGFR mutation status is not a compulsory guideline for second- or third-line treatment in clinical practice. which subgroup of advanced NSCLC could benefit from EGFR-TKIs in the second-or third-line setting remains elusive. To explore predictive factors of advanced NSCLC patients with the unknown status of EGFR mutation treated by gefitinib in the second-or third-line setting is warrant.

    Methods
    155 cases with advanced NSCLC who failed in previous platinum-based chemotherapy and received gefitinib as part of the Expanded Access Program (EAP) of the China Charity Federation were included in this study. Fifteen clinical variables were analyzed within the following general categories: demographic variables, smoking history, pathological and differentiation, involvement of specific metastasis sites, the number of comorbidities, and prior thoracic radiotherapy. Multivariate analysis of progression-free survival (PFS) was performed using recursive partitioning referred to as classification and regression tree (CART) analysis. This method uses recursive partitioning to assess the effect of specific variables on PFS, thereby ultimately generating groups of patients with similar clinical features on PFS.

    Results
    The median PFS in 155 patients with NSCLC who were treated with gefitinib after prior chemotherapy was 14 months (95% CI 13.4–18.6). CART was performed with an initial split on adenocarcinoma differentiation, followed by brain metastasis and prior thoracic radiotherapy. According to the analysis, four terminal subgroups were produced, and the median PFS was significantly different between the four terminal subgroups (P=0.011). The longest PFS subgroup was located in those patients with well-differentiated adenocarcinoma without brain metastasis, and received prior thoracic radiotherapy (mPFS 42 m). The poorest median PFS of 12 months was found in subgroup of patients with moderately and poorly-differentiated adenocarcinoma. The other two subgroup patients were well-differentiated adenocarcinoma without brain metastasis, and didn't receive prior thoracic radiotherapy (mPFS 18 m), and well-differentiated adenocarcinoma with brain metastasis (mPFS 13 m) respectively.

    Conclusion
    Adenocarcinoma differentiation, brain metastasis and prior thoracic radiotherapy are predictors of benefit of gefitinib in second- or third- line treatment after chemotherapy in advanced NSCLC. CART can be used to identify homogeneous patient populations in clinical practice and future clinical trials.