Abstract
BACKGROUND AND OBJECTIVE: The epidermal growth factor receptor tyrosine kinase inhibitor (EGFRTKI) shows favorable antitumor activity against chemorefractory non-small cell lung cancer (NSCLC). However, patients with advanced NSCLC have limited treatment options available if they are refractory to EGFR-TKI. To study the influence of the retreatment EGFR-TKI after failure of first-line TKI, we carried out this retrospective study. METHODS: Total 71 patients were analyzed who experienced treatment failure from their initial use of EGFR-TKI. After a period of time, they were retreated with TKI as tumor progression was observed. RESULTS: Of the 71 patients who received retreatment TKI, it was observed in 7% in partial response (PR), 36.6% in stable disease (SD), 56.3% in progressive disease (PD). Disease control rate (DCR) was 43.7%. Twenty-six (36.6%) patients were well controlled by retreatment with TKI monotherapy for not less than 3 months. Five (7.0%) patients had partial response. Exon 21 mutation, PFS not less than 6 months during initial treatment TKI, and the interval not less than 3 months between initial treatment, and retreatment with TKI was associated with a good progression free survival based on univariate COX analysis (P=0.034; P=0.013; P=0.046). CONCLUSIONS: It has been shown the possibility that retreatment with TKI might be useful when (1) Exon 21 has active mutation, (2) initial treatment shows a favorable PFS (≥ 6 months), and (3) there has been a period of time (≥3 months) following the termination of the initial TKI treatment.