title: Differences in the efficacy of S-1 monotherapy according to histological type in pretreated patients with advanced non-small cell lung cancer.
abstract: S-1 is a novel antimetabolic agent that inhibits thymidylate synthase. The expression of thymidylate synthase is higher in squamous (Sq) non-small cell lung cancer (NSCLC) than in non-Sq NSCLC. The aim of this retrospective study was to assess the efficacy of S-1 monotherapy for advanced NSCLC according to the histological subtype.
  
  
  
  We reviewed the clinical records of patients with advanced NSCLC treated with S-1 monotherapy as second- or third-line therapy between May 2005 and July 2012 at the Shizuoka Cancer Center.
  
  
  
  A total of 71 patients were included in this retrospective study. Patient characteristics were similar in the Sq NSCLC (n = 15) and non-Sq NSCLC (n = 56) groups, except with regard to gender and smoking status. The overall response rates were 0% (95% confidence interval [CI] 0-17%) for Sq NSCLC and 11% (95% CI 3-19%) for non-Sq NSCLC (P = 0.33). For Sq NSCLC and non-Sq NSCLC, the median progression-free survival times were 2.1 and 2.8 months (P = 0.02), respectively, and the median overall survival times were 6.1 and 10.1 months (P = 0.01), respectively.
  
  
  
  S-1 monotherapy may be more effective in patients with non-Sq NSCLC than in those with Sq NSCLC.
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan; Department of Medical Oncology, Oita University Hospital Oita, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Hisamatsu
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Haruyasu
authors.initials: H
authors.lastname: Murakami
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Akamatsu
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Madoka
authors.initials: M
authors.lastname: Kimura
authors.affiliation: Division of Clinical Trial Coordination office, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Keita
authors.initials: K
authors.lastname: Mori
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Hisao
authors.initials: H
authors.lastname: Imai
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ono
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan; Department of Respiratory Medicine, School of Medicine, Juntendo University Tokyo, Japan.
authors.forename: Takehito
authors.initials: T
authors.lastname: Shukuya
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Tetsuhiko
authors.initials: T
authors.lastname: Taira
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Hirotsugu
authors.initials: H
authors.lastname: Kenmotsu
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Tateaki
authors.initials: T
authors.lastname: Naito
authors.affiliation: Division of Diagnostic Radiology, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Endo
authors.affiliation: Division of Diagnostic Pathology, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakajima
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Division of Thoracic Oncology, Shizuoka Cancer Center Shizuoka, Japan; The Third Department of Internal Medicine, Wakayama Medical University Wakayama, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Yamamoto
keywords: Histology; S-1 monotherapy; non-small cell lung cancer; thymidylate synthase