title: Long-term health status as measured by EQ-5D among patients with metastatic breast cancer: comparison of first-line oral S-1 and taxane therapies in the randomized phase III SELECT BC trial.
abstract: The goal of chemotherapy for metastatic breast cancer (MBC) is to prolong survival and maintain health-related quality of life. This study aimed to evaluate long-term health status of patients with MBC who participated in the phase III randomized SELECT BC trial.
  
  
  
  In the SELECT BC trial, patients were randomly allocated to the S-1 or taxane (paclitaxel or docetaxel) arm. Health status was assessed by EQ-5D at pre-treatment, 3 and 6 months after randomization, and every 6 months thereafter to the extent possible. Least square mean scores were assessed to compare EQ-5D index values between groups. Time to deterioration analysis was also performed by defining the minimally important difference of EQ-5D as 0.05 or 0.1.
  
  
  
  The number of patients for EQ-5D analysis was 175 and 208 in the taxane and S-1 arms, respectively. Least square mean EQ-5D index values up to 60 months were 0.741 (95 % CI [0.713-0.769]) in the taxane arm and 0.748 [0.722-0.775] in the S-1 arm. The EQ-5D index value during PFS up to 12 months in the S-1 was superior to the corresponding index value in the taxane (0.812 [0.789-0.834] vs. 0.772 [0.751-0.792], P = 0.009). Time to deterioration analysis also revealed that S-1 significantly delayed the deterioration of EQ-5D index value during the period before progression (P = 0.002 and 0.003).
  
  
  
  Our findings suggest that the EQ-5D index value was higher in patients treated with S-1 during first-line chemotherapy. Considering non-inferiority of S-1 in terms of OS, obtained quality-adjusted life years may be greater in the S-1 arm.
authors: Department of Health and Welfare Services, National Institute of Public Health, 2-3-6 Minami, Wako, Saitama, 351-0197, Japan. t.shiroiwa@gmail.com.
authors: T
authors: T
authors: Shiroiwa
authors: Department of Health and Welfare Services, National Institute of Public Health, 2-3-6 Minami, Wako, Saitama, 351-0197, Japan.
authors: T
authors: T
authors: Fukuda
authors: Department of Biomedical Sciences, College of Life Sciences, Ritsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, 525-8577, Japan.
authors: K
authors: K
authors: Shimozuma
authors: Kanagawa Academy of Science and Technology (KAST), 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012, Japan.
authors: M
authors: M
authors: Mouri
authors: Department of Biostatistics, School of Public Health, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors: Y
authors: Y
authors: Hagiwara
authors: Breast and Endocrine Surgery Department, Okayama University Hospital, 2-5-1 Shikata-cho, Kita-ku, Okayama, 700-8558, Japan.
authors: H
authors: H
authors: Doihara
authors: Department of Surgery, Hokkaido P.W.F.A.C. Asahikawa-Kosei General Hospital, 24-111 Ichijo dori, Asahikawa, Hokkaido, 078 8211, Japan.
authors: H
authors: H
authors: Akabane
authors: Department of Surgery, Iwate Medical University, 19-1 Uchimaru, Morioka, Iwate, 020-8505, Japan.
authors: M
authors: M
authors: Kashiwaba
authors: Department of Breast Surgery, Sendai Medical Center, 2-8-8 Miyagino, Miyagino-ku, Sendai, Miyagi, 983-8520, Japan.
authors: T
authors: T
authors: Watanabe
authors: Department of Integrated Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo-ku, Tokyo, 112-8551, Japan.
authors: Y
authors: Y
authors: Ohashi
authors: Division of Breast and Medical Oncology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa, Chiba, 277-8577, Japan.
authors: H
authors: H
authors: Mukai
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy / Q000523:psychology*; D004338:Drug Combinations; D005260:Female; D006304:Health Status; D006801:Humans; D008875:Middle Aged; D010094:Oxonic Acid / Q000627:therapeutic use*; D011788:Quality of Life; D019057:Quality-Adjusted Life Years; D011795:Surveys and Questionnaires; D043823:Taxoids / Q000627:therapeutic use*; D005641:Tegafur / Q000627:therapeutic use*
chemical_list: D004338:Drug Combinations; D043823:Taxoids; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid
keywords: Breast cancer; EQ-5D; Health-related quality of life; Randomized controlled trial; S-1; Taxane