title: Preoperative imatinib for patients with primary unresectable or metastatic/recurrent gastrointestinal stromal tumor.
abstract: OBJECTIVE
  Despite its rising popularity, reports on the use of preoperative imatinib mesylate (IM) in patients with advanced gastrointestinal stromal tumor (GIST) are limited. This study aims to explore the clinical efficacy of preoperative IM in patients with primarily unresectable or metastatic/recurrent GIST.
  
  
  METHODS
  Between September 2009 and February 2014, patients with primarily unresectable or metastatic/recurrent GIST treated by a single medical team were recruited and considered for preoperative IM therapy. Re-examination was conducted regularly and abdominal enhanced CT data, blood biochemistry and responses to IM were recorded.
  
  
  RESULTS
  A total of 18 patients were enrolled, including 13 with a primary tumor (7 stomach, 3 small bowel, 2 rectal and 1 pelvic tumor) and 5 with recurrent or metastatic GIST (2 with liver metastasis, 2 with anastomotic recurrence and 1 with pelvic GIST). The median follow-up time was 9.5 months (range of 3-63). The median tumor sizes before and after initiation of IM treatment were 9.1 cm and 6.0 cm (p=0.003) based on the CT findings, respectively. All patients showed a decrease in tumor burden and the median tumor size reduction was 35%. Sixteen of the 18 patients showed a partial response to IM and two possessed stable disease. Nine of the 18 patients (50%) underwent surgical resection of primary or metastatic/recurrent tumors, with a median of 7 months of IM therapy. One case each of multivisceral resection and tumor recurrence were noted.
  
  
  CONCLUSIONS
  IM as a preoperative therapy is feasible and safe for unresectable or metastatic/recurrent GIST that can effectively decrease tumor size, facilitating resection.
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chendu, Sichuan Province, China.
authors.forename: Chaoyong
authors.initials: C
authors.lastname: Shen
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chendu, Sichuan Province, China.
authors.forename: Haining
authors.initials: H
authors.lastname: Chen
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chendu, Sichuan Province, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yin
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chendu, Sichuan Province, China.
authors.forename: Jiaju
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chendu, Sichuan Province, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chendu, Sichuan Province, China.
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chendu, Sichuan Province, China.
authors.forename: Jiaping
authors.initials: J
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001549:Benzamides / Q000627:therapeutic use*; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000473:pathology / Q000556:secondary / Q000601:surgery; D006801:Humans; D000068877:Imatinib Mesylate; D008113:Liver Neoplasms / Q000556:secondary; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009362:Neoplasm Metastasis / Q000188:drug therapy; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000473:pathology / Q000601:surgery; D010879:Piperazines / Q000627:therapeutic use*; D011300:Preoperative Care; D057234:Preoperative Period; D011743:Pyrimidines / Q000627:therapeutic use*; D015203:Reproducibility of Results; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D000970:Antineoplastic Agents; D001549:Benzamides; D010879:Piperazines; D011743:Pyrimidines; D000068877:Imatinib Mesylate