A Study of Tarceva vs. Avastin+Tarceva for Advanced NSCLC With EGFR m(+)

Inclusion Criteria: * Pathologically confirmed stage IIIB \& IV non-small cell lung cancer other than squamous cell carcinoma * Patients with one or more measurable lesion based on Response Evaluation Criteria in Solid Tumors (RECIST 1.1) * Locally diagnosed sensitive EGFR mutation positive (Exon 19 deletion or L858R) * ECOG performance 0\~1 * Age ≥ 19 years and - No previous treatment Adequate organ function by following: * ANC ≥1,500/uL, hemoglobin ≥9.0g/dL, platelet ≥100,000/uL * Serum bilirubin \< 1 x UNL, AST (SGOT) and ALT (SGPT) \< 2.5 x UNL, If Liver metastasis, Serum bilirubin \< 3 x UNL, AST (SGOT) and ALT (SGPT) \< 5 x UNL * Serum Cr ≤ 1 x UNL * Patients who have had undergone radiotherapy are acceptable if patients meet all of the following criteria: * No history of irradiation to pulmonary tumor lesions. * In case of palliative irradiation to bone lesions in lung: at least 12 weeks must have passed at the date of registration since the last irradiation of the sites. * In case of irradiation to non-pulmonary sites: at least two weeks must have passed at the date of inclusion since the last irradiation of the sites * At the time of registration, at least the following period has passed since last date of the prior therapy or procedure: * Surgery(including exploratory/ examination thoracotomy): 4 weeks * Pleural cavity drainage: 1 weeks * Pleurodesis without anti-neoplastic agents (inclusive of BRM such as Picibanil): 2 week * Biopsy accompanied by incision (including thoracoscopic biopsy): 2 week * Procedure for trauma (exclusive of patients with unhealed wound): 2 weeks * Transfusion of blood, preparation of hematopoietic factor: 2 week * Puncture and aspiration cytology: 1 week * Other investigational product: 4 weeks * Written informed consent form Exclusion Criteria: * Previous history of malignancy within 3 years from study entry except treated non-melanomatous skin cancer, uterine cervical cancer in situ, or thyroid cancer * Prior chemotherapy or systemic anti-cancer therapy for metastatic disease but postoperative adjuvant or neoadjuvant therapy of 6 months or more previously is allowed * Patients who received previous treatment for lung cancer with drugs * Symptomatic or uncontrolled central nervous system (CNS) metastases * Patients with increased risk of bleeding, clinically significant cardiovascular diseases, a history of thrombosis or thromboembolism in the 6 months prior to treatment, gastrointestinal problems, and neurologic problems * Any significant ophthalmologic abnormality * Pre-existing parenchymal lung disease such as pulmonary fibrosis * Known allergic history of Erlotinib or Bevacizumab * Interstitial lung disease or fibrosis on chest radiogram * Active infection, uncontrolled systemic disease (cardiopulmonary insufficiency, fatal arrhythmias, hepatitis) * Pregnant or nursing women