title: Conversion therapy for inoperable advanced gastric cancer patients by docetaxel, cisplatin, and S-1 (DCS) chemotherapy: a multi-institutional retrospective study.
abstract: Conversion therapy is an option for unresectable metastatic gastric cancer when distant metastases are controlled by chemotherapy; however, the feasibility and efficacy remain unclear. This study aimed to assess the feasibility and efficacy of conversion therapy in patients with initially unresectable gastric cancer treated with docetaxel, cisplatin, and S-1 (DCS) chemotherapy by evaluating clinical outcomes.
  
  
  
  One hundred unresectable metastatic gastric cancer patients, enrolled in three DCS chemotherapy clinical trials, were retrospectively evaluated. The patients received oral S-1 (40 mg/m2b.i.d.) on days 1-14 and intravenous cisplatin (60 mg/m2) and docetaxel (50-60 mg/m2) on day 8 every 3 weeks. Conversion therapy was defined when the patients could undergo R0 resection post-DCS chemotherapy and were able to tolerate curative surgery.
  
  
  
  Conversion therapy was achieved in 33/100 patients, with no perioperative mortality. Twenty-eight of the 33 patients (84.8 %) achieved R0 resection, and 78.8 % were defined as histological chemotherapeutic responders. The median overall survival (OS) of patients who underwent conversion therapy was 47.8 months (95 % CI 28.0-88.5 months). Patients who underwent R0 resection had significantly longer OS than those who underwent R1 and R2 resections (P = 0.0002). Of the patients with primarily unresectable metastases, 10 % lived >5 years. Among patients who underwent conversion therapy, multivariate analysis showed that the pathological response was a significant independent predictor for OS.
  
  
  
  DCS safely induced a high conversion rate, with very high R0 and pathological response rates, and was associated with a good prognosis; these findings warrant further prospective investigations.
authors.affiliation: Department of Medical Oncology and Hematology, Sapporo Medical University School of Medicine, South 1 West 16, Chuo-ku, Sapporo, 060-8543, Japan. yasushis2008@gmail.com.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Medical Oncology and Hematology, Sapporo Medical University School of Medicine, South 1 West 16, Chuo-ku, Sapporo, 060-8543, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ohnuma
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nobuoka
authors.affiliation: Department of Medical Oncology and Hematology, Sapporo Medical University School of Medicine, South 1 West 16, Chuo-ku, Sapporo, 060-8543, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hirakawa
authors.affiliation: Department of Gastroenterology, Hokkaido Cancer Center, Sapporo, Japan.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Sagawa
authors.affiliation: Department of Gastroenterology, Hokkaido Cancer Center, Sapporo, Japan.
authors.forename: Koshi
authors.initials: K
authors.lastname: Fujikawa
authors.affiliation: Department of Gastroenterology, Hokkaido Cancer Center, Sapporo, Japan.
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Department of Gastroenterology, Oji General Hospital, Tomakomai, Japan.
authors.forename: Minami
authors.initials: M
authors.lastname: Shinya
authors.affiliation: Department of Gastroenterology, Otaru Ekisaikai Hospital, Otaru, Japan.
authors.forename: Shinich
authors.initials: S
authors.lastname: Katsuki
authors.affiliation: Department of Gastroenterology, Sapporo Kyoritsu Gorinbashi Hospital, Sapporo, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Gastroenterology, Steel Memorial Muroran Hospital, Muroran, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Maeda
authors.affiliation: Department of Medical Oncology and Hematology, Sapporo Medical University School of Medicine, South 1 West 16, Chuo-ku, Sapporo, 060-8543, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Okagawa
authors.affiliation: Department of Medical Oncology and Hematology, Sapporo Medical University School of Medicine, South 1 West 16, Chuo-ku, Sapporo, 060-8543, Japan.
authors.forename: Uemura
authors.initials: U
authors.lastname: Naoki
authors.affiliation: Department of Medical Oncology and Hematology, Sapporo Medical University School of Medicine, South 1 West 16, Chuo-ku, Sapporo, 060-8543, Japan.
authors.forename: Syouhei
authors.initials: S
authors.lastname: Kikuch
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Okamoto
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyamoto
authors.affiliation: Department of Digestive and Pediatric Surgery, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Shimada
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Takemasa
authors.affiliation: Department of Medical Oncology and Hematology, Sapporo Medical University School of Medicine, South 1 West 16, Chuo-ku, Sapporo, 060-8543, Japan.
authors.forename: Junji
authors.initials: J
authors.lastname: Kato
authors.affiliation: Department of Gastroenterology and Oncology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Takayama
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002945:Cisplatin / Q000008:administration & dosage; D000077143:Docetaxel; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010094:Oxonic Acid / Q000008:administration & dosage; D011182:Postoperative Care; D011379:Prognosis; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery; D016019:Survival Analysis; D043823:Taxoids / Q000008:administration & dosage; D005641:Tegafur / Q000008:administration & dosage; D016896:Treatment Outcome
chemical_list: D004338:Drug Combinations; D043823:Taxoids; C079198:S 1 (combination); D005641:Tegafur; D000077143:Docetaxel; D010094:Oxonic Acid; D002945:Cisplatin
keywords: Conversion therapy; DCS; Gastric cancer