The purpose of this study is to compare 3years of disease-free survival (DFS) of Icotinib and placebo in the treatment of patients who EGFR mutation-positive II-IIIA lung adenocarcinoma.

This study is designed to compare 3 years of disease-free survival (DFS) of Icotinib and placebo in the treatment of patients who EGFR mutation-positive II-IIIA lung adenocarcinoma.

Primary Outcome Measure:

Disease-free survival between Icotinib group and placebo group.

Secondary Outcome Measures:

Overall survival between Icotinib group and placebo group. Lung cancer symptoms and health-related quality of life (HRQoL) . Number of participants with adverse events.

Inclusion Criteria:

• Pathologically confirmed lung adenocarcinoma after surgical resection
• Stage II-IIIA disease according to 7th edition of TNM staging
• Patients must harbor sensitive EGFR gene mutation (19/21)
• Received four cycles of platinum-based adjuvant chemotherapy.There are many different kinds of chemotherapy regimens including vinorelbine, gemcitabine, docetaxel, paclitaxel, pemetrexed plus cisplatin or carboplatin.The first cycle of chemotherapy with cisplatin dose of 75 mg / m2 ± 10% or carboplatin AUC = 5 ± 10% to calculate the dose of chemotherapy

Exclusion Criteria:

• Previous systemic anti-tumor therapy, including chemotherapy or targeted therapy(Including but not limited to monoclonal antibodies, small molecule tyrosine kinase inhibitor, etc
• Presence of metastatic disease
• Other co-existing malignancies or malignancies diagnosed within the last 5 years with the exception of basal cell carcinoma or cervical cancer in situ
• Any unresolved chronic toxicity from previous anticancer therapy
• Received antitumor radiation therapy (except for the stage IIIA N2 patients who received adjuvant radiotherapy after surgery)