Characteristics and overall survival of EGFR mutation-positive non-small cell lung cancer treated with EGFR tyrosine kinase inhibitors: a retrospective analysis for 1660 Japanese patients.
BACKGROUND
The Japan Guidelines of Lung Cancer Therapy recommend epidermal growth factor receptor-tyrosine kinase inhibitors as a first-line therapy for advanced/recurrent non-small cell lung cancer patients with epidermal growth factor receptor mutation. Although survival periods in recent reports of epidermal growth factor receptor-tyrosine kinase inhibitor treatment have been getting longer, the reasons why are unclear. We investigated the survival, prognostic factors and real-world treatment of non-small cell lung cancer patients with epidermal growth factor receptor mutation in clinical practice.


METHODS
Non-small cell lung cancer patients (n = 1660) who started first-line treatment from January 2008 to December 2012 were enrolled. Patients were diagnosed with epidermal growth factor receptor mutation-positive advanced/recurrent non-small cell lung cancer by histology or cytology samples. The primary objective was to estimate overall survival. The secondary objectives were to determine prognostic factors, real-world treatment patterns and efficacy of gefitinib treatment. We calculated the treatment exposure rate for each treatment category using the following formula: exposure rate = person-years for the treatment category/total person-years × 100.


RESULTS
The median overall survival was 30.8 months. Sex, age, histology, epidermal growth factor receptor mutation type, clinical stage and performance status affected overall survival. The exposure rates for all epidermal growth factor receptor-tyrosine kinase inhibitors, gefitinib and platinum-doublet chemotherapy were 62.1, 46.4 and 8.5% respectively. Overall 56.1% of patients were administered gefitinib as first-line therapy, and 39.0% were treated with ≥2 epidermal growth factor receptor-tyrosine kinase inhibitor regimens. The median progression-free survival in the first-line gefitinib group was 11.4 months. Factors affecting prognosis were sex, histology, clinical stage and performance status.


CONCLUSION
Epidermal growth factor receptor-tyrosine kinase inhibitors, especially gefitinib, are major components of the treatment regimens for epidermal growth factor receptor mutation-positive non-small cell lung cancer. Switching and re-challenging with epidermal growth factor receptor-tyrosine kinase inhibitors were also practiced in Japan.
['Inoue|Akira|A|', 'Yoshida|Kazushi|K|', 'Morita|Satoshi|S|', 'Imamura|Fumio|F|', 'Seto|Takashi|T|', 'Okamoto|Isamu|I|', 'Nakagawa|Kazuhiko|K|', 'Yamamoto|Nobuyuki|N|', 'Muto|Satoshi|S|', 'Fukuoka|Masahiro|M|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D044466:Asians D002289:Carcinoma, Non-Small-Cell Lung D018572:Disease-Free Survival D066246:ErbB Receptors D005260:Female D000077156:Gefitinib D006801:Humans D007564:Japan D008175:Lung Neoplasms D008297:Male D008875:Middle Aged D009154:Mutation D009364:Neoplasm Recurrence, Local D009367:Neoplasm Staging D011379:Prognosis D016016:Proportional Hazards Models D047428:Protein Kinase Inhibitors D011799:Quinazolines D012189:Retrospective Studies D015996:Survival Rate
non-small cell lung cancer EGFR tyrosine kinase inhibitor mutation gefitinib