Objective: the objective of this study in china is to clarify, whether the overall survival is different between previously untreated stage IIIB/IV lung adenocarcinoma with EGFR mutations receiving first-line erlotinib plus second-line docetaxel/cisplatin and those receiving first-line docetaxel/cisplatin plus second-line erlotinib .

Inclusion Criteria:

• Male and female patients aged over 18 years
• Histologically proven lung adenocarcinoma
• clinical stage IIIB/IV
• ECOG performance status 0-2
• Had no prior anticancer agent, radiation or surgical therapy for lung adenocarcinoma
• At least one measurable lesion (according to RECIST)
• Provision of written informed consent
• Life expectancy of at least 12 weeks

Exclusion Criteria:

• History of malignant disease.
• Evidence of clinically active interstitial lung diseases (patients with chronic, stable, radiographic changes who are asymptomatic need not be excluded)
• Expected life expectancy less than 2 months
• As judged by the investigator, any evidence of severe or uncontrolled systemic disease (e.g. unstable or uncompensated respiratory, cardiac, hepatic, or renal disease)
• Aspartate aminotransferase (AST/SGOT) or alanine aminotransferase (ALT/SGPT) ≥ 2.5 x ULN if no demonstrable liver metastases (or >5 x in presence of liver metastases)
• Evidence of any other significant clinical disorder or laboratory finding that makes it undesirable for the subject to participate in the study
• Pregnancy or breast-feeding women (women of child¬bearing potential). Women of childbearing potential must practice acceptable methods of birth control to prevent pregnancy.