Variability in the anti-tumor effect of tegafur-uracil depending on histologic types of lung cancer.

Abstract

Tegafur-uracil (UFT) is an anticancer agent that inhibits thymidylate synthase (TS). The degree of TS expression in primary lung cancer (LC) is different according to histologic cell type. In this study, we examined the variability of the anti-tumor efficacy of UFT monotherapy depending on histological subtypes of LC. In the current single-institution, retrospective study, we assigned the patients with LC to three histologic groups [the squamous (Sq) non-small cell lung cancer (NSCLC)] group, the non-Sq NSCLC group and the SCLC group] and then compared the clinical response to UFT monotherapy between the three groups. Our clinical series of 149 patients include 54 cases of Sq NSCLC, 67 cases of non-Sq NSCLC and 28 cases of SCLC. For Sq NSCLC, non-Sq NSCLC and SCLC group, the overall response rates (ORRs) were 1%, 1% and 0% (P=0.522), respectively. The disease control rates (DCRs) were 38.9%, 31.3% and 10.7% (P=0.012), respectively. The median progression-free survivals (PFSs) were 2.68, 2.25 and 1.46 months (P=0.004 for three groups and P=0.773 for two groups except for the SCLC group at the log-rank test), respectively. There was no significant difference between the groups in median overall survival (OS). Our results indicate that the degree of the anti-tumor effect of UFT was higher in patients with NSCLC as compared with SCLC. But it showed no significant difference between the patients with Sq NSCLC and those with non-Sq NSCLC.