S1 vs.Pemetrexed Plus Carboplatin in Patients With EGFR Wild Type Stage IIIB or IV Nonsquamous NSCLC

Inclusion Criteria: 1. Chemotherapy-naive patients with histologically or cytologically confirmed nonsquamous NSCLC, classified as stage IIIB not amenable to curative treatment or stage IV; EGFR wild type. 2. At least one unidimensionally measurable lesion according to the Response Evaluation Criteria in Solid Tumors 3. Eastern Cooperative Oncology Group performance status of 0 or 1 4. 18 \<age\<75 years 5. Patients had adequate bone marrow reserve and organ function. 6. Prior radiation therapy was permitted if it was completed at least 4 weeks before study treatment and patients had fully recovered from its acute effects 7. Written informed consent was obtained directly from every patient 8. Estimated life expectancy of at least 12 weeks. 9. Patient compliance and geographic proximity that allow adequate follow up. 10. Male and female patients with reproductive potential must use an approved contraceptive method, if appropriate during and for 3 months after the study. Women with childbearing potential must have a negative serum pregnancy test within 7 days prior to study enrollment. Exclusion Criteria: 1. Brain metastasis associated with central nervous symptoms (patients were eligible if symptoms were controlled by steroids or other treatments); 2. Serious infections or other serious complications. 3. Uncontrolled third-space fluid retention before study entry. unable to interrupt aspirin and other nonsteroidal anti-inflammatory drugs or if they were unable or unwilling to take folic acid, vitamin B12, or corticosteroids 4. Have a prior malignancy other than NSCLC, carcinoma in situ of the cervix, or nonmelanoma skin cancer, unless that prior malignancy was diagnosed and definitively treated at least 5 years previously with no subsequent evidence of recurrence. 5. Pregnant or breast feeding. 6. A distinct history of drug allergies