title: Phase II study of S-1 in combination with trastuzumab for HER2-positive metastatic breast cancer.
abstract: OBJECTIVE
  We undertook a prospective phase II study to evaluate the efficacy of S-1 plus trastuzumab combination regimen for human epidermal-growth factor receptor-2 (HER2)-positive metastatic breast cancer (MBC).
  
  
  METHODS
  HER2-positive MBC patients received oral administration of S-1 (80 mg/m2/day, days 1 to 28, every 6 weeks) and intravenous weekly trastuzumab (2 mg/kg), according to the results of a prior Phase I trial of our group.
  
  
  RESULTS
  A total of 28 patients were enrolled and received a median of 3.5 (range 1-10) cycles of treatment. Overall response rate and clinical benefit rate were 53.6% and 75.0%, respectively. Progression-free survival was 30 weeks. With regard to grade 3 and 4 adverse effects, leucopenia, neutropenia, increase in serum alanine aminotransferase, and diarrhea were observed.
  
  
  CONCLUSIONS
  Combination of S-1 and trastuzumab was tolerable and had excellent efficacy with good response and disease control in this trial.
authors: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan tsutomu-@rd5.so-net.ne.jp.
authors: Tsutomu
authors: T
authors: Takashima
authors: Department of Breast and Endocrine Surgery, Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.
authors: Takahiro
authors: T
authors: Nakayama
authors: Department of Surgery, Osaka Police Hospital, Osaka, Japan.
authors: Katsuhide
authors: K
authors: Yoshidome
authors: Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors: Hidemi
authors: H
authors: Kawajiri
authors: Department of Surgery, Sakai Municipal Hospital, Sakai, Japan.
authors: Shunji
authors: S
authors: Kamigaki
authors: Department of Medical Oncology, Kinki University Faculty of Medicine, Osaka, Japan.
authors: Junji
authors: J
authors: Tsurutani
authors: Takebe Breast Care Unit, Kagawa Japan.
authors: Takashi
authors: T
authors: Arai
authors: Department of Surgery, Rinku General Medical Center, Osaka, Japan.
authors: Toshikazu
authors: T
authors: Ito
authors: Department of Breast and Endocrine Surgery, Kinki University Faculty of Medicine, Osaka, Japan.
authors: Yoshihumi
authors: Y
authors: Komoike
authors: Department of Breast Cancer Oncology, Shonan Memorial Hospital, Kanagawa, Japan.
authors: Takako
authors: T
authors: Doi
authors: Department of Surgery, Breast Oncology, NHO Osaka National Hospital,Osaka, Japan.
authors: Norikazu
authors: N
authors: Masuda
authors: Miyauchi Clinic, Hyogo, Japan.
authors: Keisuke
authors: K
authors: Miyauchi
authors: Department of Breast and Endocrine Surgery, Hyogo College of Medicine, Hyogo, Japan.
authors: Yasuo
authors: Y
authors: Miyoshi
authors: Young Leaders' Program in Healthcare Administration, Nagoya University Graduate School of Medicine, Nagoya, Japan.
authors: Junichi
authors: J
authors: Sakamoto
authors: Department of Biostatistics and Epidemiology, Yokohama City University Medical Center, Kanagawa, Japan.
authors: Satoshi
authors: S
authors: Morita
authors: Department of Endocrine and Breast Surgery, Kyoto Prefectural University of Medicine, Kyoto, Japan.
authors: Tetsuya
authors: T
authors: Taguchi
mesh_terms: D000284:Administration, Oral; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage / Q000009:adverse effects; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000473:pathology; D018572:Disease-Free Survival; D004334:Drug Administration Schedule; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000201:enzymology / Q000473:pathology; D010094:Oxonic Acid / Q000008:administration & dosage / Q000009:adverse effects; D011446:Prospective Studies; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D005641:Tegafur / Q000008:administration & dosage / Q000009:adverse effects; D000068878:Trastuzumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D004338:Drug Combinations; D010094:Oxonic Acid; D018719:Erb-b2 Receptor Tyrosine Kinases; D005641:Tegafur; D000068878:Trastuzumab; C079198:S 1 (combination); C508053:ERBB2 protein, human
keywords: HER2-positivity; S-1; first-line therapy; metastatic breast cancer; trastuzumab