The characteristics and failure pattern of gefitinib responders with postoperative recurrence of pulmonary adenocarcinoma.

AIMS: Gefitinib shows prominent anti-tumor activity against advanced or recurrent non-small cell lung cancer (NSCLC). However, most gefitinib-responsive patients ultimately relapse. We reviewed postoperatively recurrent NSCLC patients who received gefitinib treatment, and analyzed both the clinical features and manifestations of treatment failure in patients who initially responded to gefitinib.
METHODS: From 2002 to 2006, gefitinib was administered to in 34 postoperative recurrent lung adenocarcinoma patients. There were 13 men and 21 women with a mean age of 65 years. Twenty patients had never smoked while 14 were former smokers. Epidermal growth factor receptor (EGFR) gene mutation was measured using surgical specimens of the primary tumor.
RESULTS: The study group showed 1 complete response, 16 partial responses, 7 stable diseases and 8 progressive diseases. Mutations of EGFR gene were detected in 20 of 34 patients. Only the presence of EGFR gene mutations was significantly associated with the clinical response of gefitinib in our limited study (p=0.036). In 9 of 12 responders, gefitinib treatment failed due to the appearance of new lesions.
CONCLUSIONS: Gefitinib was significantly effective for patients with mutations of the EGFR gene and most responders failed due to the appearance of new lesions without progression of the pre-existent target lesions.