[Effect of Adjuvant Chemotherapy on DFS for Patients with Stage I NSCLC]

Surgical resection is the best choice for early lung cancer, but the prognosis of early postoperative lung cancer is still very different, whether or not to apply adjuvant chemotherapy is controversial. This study examines the role of postoperative adjuvant chemotherapy in patients with stage I non-small cell lung cancer (NSCLC), particularly in high-risk groups.

Patients with pathologic stage Ia and stage Ib NSCLC who underwent complete (R0) resection between January 2009 and June 2013 were identified from Peking University People's Hospital and classified into two groups based on postoperative chemotherapy or not. Kaplan-Meier and Log-rank tests were used to compare disease free survival (DFS). Scored according to the number of risk factors, all patients were divided into three groups. Kaplan-Meier and Log-rank tests were used to compare DFS between them. The effect of postoperative chemotherapy on high-risk group was observed individually.

A total of 465 patients including 284 cases of stage Ia and 181 cases of stage Ib were enrolled in this study. For stage Ia there was no significant difference between the chemotherapy group and the control group in DFS (P=0.171), but the survival curve of the chemotherapy group was located below the control group. For stage Ib there was no significant difference between the two groups either (P=0.630). But there were significant differences on DFS between the three groups according to the number of risk factors (P<0.001). The more risk factors mean the worse DFS. However, independent analyses showed no significant effect of postoperative chemotherapy on DFS in the high-risk group patients (P=0.763).

Postoperative chemotherapy does not have a positive effect on DFS in early stage non-small cell lung cancer, and chemotherapy may not be appropriate even for patients with multiple risk factors.