Multicenter Randomized Controlled Trial Adjuvant Chemotherapy vs Observation in pStage Ib Lung Adenocarcinoma

Researchers developed the nomogram which evaluate the risk of recurrence after surgical resection, and found that the stage 1 NSCLC patients with more than 104 point of nomogram showed similar recurrence rate to the recurrence rate of stage 2 NSCLC patients. Thus those stage 1 NSCLC patients at high recurrence rate are considered to show positive effect of adjuvant chemotherapy and perform the study to prove this hypothesis. Applying the nomogram, the patient scored lower than 104 is categorized into low risk group and is to be grouped as the observation group which adjuvant chemotherapy will not be given. The high risk group patients (the nomogram scored larger than 104) are randomly divided into the treatment group and the observation group. Then, the clinical result on the recurrence between the observation group and the treatment group will be compared. \- Regimen of the adjuvant chemotherapy: The most commonly used 1st line chemotherapy regimen which is vinorelbine plus cisplatin will be admitted for 4 cycles. Also the three days before and the after the estimated day are permitted as allowance. Intravenous administration of vinorelbine (25mg/m2), the 1st and the 8th day of the each cycle, every 3 weeks. Intravenous administration of cisplatin (75mg/m2), the 1st day of the each cycle, every 3 weeks.