Impact of pathological stage and histological subtype on clinical outcome of adjuvant chemotherapy of paclitaxel plus carboplatin versus oral uracil-tegafur for non-small cell lung cancer: subanalysis of SLCG0401 trial.

Background: Pathological stage (pStage) and histological subtype are strong determinants of the treatment strategy for non-small cell lung cancer (NSCLC). Setouchi Lung Cancer study Group (SLCG) recently reported the results of a multicenter trial (SLCG0401) indicating that paclitaxel plus carboplatin (CBDCA/PTX) as adjuvant chemotherapy does not yield better survival than uracil-tegafur (UFT) in NSCLC patients with pStage IB-IIIA disease, while stratified analyses considering the pStage and histological subtype have not been performed.

Methods: We reanalyzed the overall survival (OS) and relapse-free survival (RFS) in 402 patients who had been randomly assigned to receive CBDCA/PTX or UFT by multivariate analysis with adjustments for the pStage and histological subtype.

Results: There were no significant differences in the OS or RFS between the two treatment settings either in the entire cohort (n = 402) and in some of subsets: pStage IB (n = 228), pStage II (n = 117), adenocarcinoma (AD, n = 265), and squamous cell carcinoma (SQ, n = 101). In pStage IIIA patients (n = 57), CBDCA/PTX yielded superior RFS to UFT [hazard ratio (HR) 0.44; P = 0.016]. Among the patients with non-AD and non-SQ histology (n = 36), UFT yielded both superior OS and RFS to CBDCA/PTX (HRs 0.16 and 0.23; P = 0.046 and 0.011, respectively).

Conclusions: There are subsets of patients in which one or the other between UFT and CBDCA/PTX is significantly more effective. Selection of adjuvant therapy for NSCLC patients needs to be made taking into consideration the pStage and histological subtype.