A Phase II Study of Erlotinib in Benefitted Patients With Asymptomatic Brain Metastases Advanced Non-Small Cell Lung Cancer By Chemotherapy.

This is a non-randomized open-label uncontrolled phase II trial evaluating efficacy and toxicity of erlotinib in patients with asymptomatic brain metastasis advanced NSCLC who was benefitted by first line chemotherapy. Patients with stage IV NSCLC who have one or more asymptomatic brain metastasis who was benefitted by first line chemotherapy will receive oral erlotinib 150mg once daily until disease progression or unacceptable toxicity. These patients' direct DNA sequencing of tumor tissue EGFR exons 18-21 will be analyzed The response was evaluated by RECIST criteria after the patient received erlotinib 6 weeks.If the patients present with progress disease of brain metastasis after the therapy of erlotinib, the patients will receive irradiation of brain metastasis.If the response is stable disease,partial response or complete response,he will be examined by brain MRI every 12 weeks.