High Dose Icotinib in Advanced Non-small Cell Lung Cancer With EGFR 21 Exon Mutation

Inclusion Criteria: * Histologically or cytologically confirmed stage IIIB/IV lung cancer(exclude patients confirmed by sputum cytology) * Positive EGFR 21 exon mutation or 19 exon deletion * Age 18-75 years old with performance status of 0 to 2 * With a measurable disease(longest diameters \>=10mm with Spiral computed tomography (CT)and \>=20mm with conventional CT) according to RECIST Criteria * Adequate hematological, biochemical and organ functions. Exclusion Criteria: * Severe systemic disease out of control such as unstable or uncompensated respiratory,cardiac,liver,renal diseases. * Evidence of interstitial lung diseases * Evidence of any other significant clinical disorder or laboratory finding that makes it undesirable for the subject to participate in the study