Survival outcome assessed according to tumor response and shrinkage pattern in patients with EGFR mutation-positive non-small-cell lung cancer treated with gefitinib or erlotinib

Masayuki Takeda, Isamu Okamoto, Kazuhiko Nakagawa

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39 Citations (Scopus)


INTRODUCTION:: Somatic mutations in the epidermal growth factor receptor gene (EGFR) are associated with a marked therapeutic response to EGFR-tyrosine kinase inhibitors (TKIs) in patients with advanced non-small cell lung cancer (NSCLC). Clinical indicators of the likely survival benefit of EGFR-TKI treatment in NSCLC patients with EGFR mutations have not been identified, however. We therefore evaluated progression-free survival (PFS) and overall survival (OS) according to tumor response and tumor shrinkage pattern in such patients. METHODS:: Among 145 EGFR mutation-positive NSCLC patients treated with EGFR-TKIs, 68 individuals were selected for analysis. RESULTS:: Of the 68 selected patients, 6 achieved a complete response (CR), 42 a partial response (PR), and 14 stable disease (SD). Both PFS and OS were significantly longer in patients who achieved a CR or PR than in those who experienced SD. Multivariate analysis showed that a response (CR or PR) to EGFR-TKIs was significantly associated with both PFS and OS. Among the CR/PR group, the median maximal tumor shrinkage relative to baseline was 56%, and the median time to response (TTR) was 4.2 weeks. The subsets of these patients who experienced rapid tumor regression (TTR of ≤4.2 weeks) or a high degree of tumor shrinkage (≥56%) did not show a more favorable PFS or OS compared with those who experienced slow tumor regression or a low degree of tumor shrinkage. CONCLUSION:: Response (CR or PR) may represent the optimal surrogate for efficacy among EGFR mutation-positive NSCLC patients treated with EGFR-TKIs.

Original languageEnglish
Pages (from-to)200-204
Number of pages5
JournalJournal of Thoracic Oncology
Issue number2
Publication statusPublished - Feb 1 2014


All Science Journal Classification (ASJC) codes

  • Oncology
  • Pulmonary and Respiratory Medicine

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