title: Preoperative imatinib mesylate (IM) for huge gastrointestinal stromal tumors (GIST).
abstract: BACKGROUND
  Preoperative imatinib mesylate (IM) treatment has not yet been standardized. Here, we aim to further explore such therapy on patients with gastrointestinal stromal tumors (GIST) retrospectively.
  
  
  METHODS
  Patients experiencing preoperative IM were identified from January 2009 to February 2015.
  
  
  RESULTS
  A total of 28 GIST patients were identified. The patients received preoperative IM treatment for a median length of 13.5 months, ranging from 5 to 37 months. PR and SD were observed in 24 (85.7%) and 4 (15.3%) patients, respectively. The tumor shrinkage occurred predominantly within 6 to 12 months, and slight tumor shrinkage could be observed after 12 months in certain patients. Nineteen patients (67.9%) received surgery, and R0 resection was acquired in 18 (94.7%) patients. The initial mean maximum diameter was 10.5 (5.2 to 19.0) cm and decreased to 5.9 (2.7 to 19.0) cm after preoperative treatment with a median length of 12 (ranging from 5 to 36) months (P < 0.001) in patients receiving operations. Three in 7 cases of rectum GIST underwent abdominoperineal resection, and four others adopted sphincter-sparing resection. Partial gastrectomy was performed in four patients.
  
  
  CONCLUSIONS
  IM prior to surgery can effectively prevent tumor rupture and facilitate surgery with low surgical morbidity for GIST patients. Tumor shrinkage following IM occurred predominantly within 6 to 12 months, and slight tumor shrinkage could be observed after 12 months in certain patients. In selected patients, prolonged exposure to IM is seemingly advisable under close radiological surveillance.
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
authors.forename: Sumin
authors.initials: S
authors.lastname: Tang
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Yin
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
authors.forename: Chaoyong
authors.initials: C
authors.lastname: Shen
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
authors.forename: Jiaju
authors.initials: J
authors.lastname: Chen
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Yin
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China. hxwcwk@126.com.
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Department of Research Center for Public Health and Preventive Medicine, West China School of Public Health/No. 4 West China Teaching Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
authors.forename: Yuqin
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Department of State Key Laboratory of Biotherapy/Collaborative Innovation Center for Biotherapy, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
authors.forename: Jinliang
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Gastrointestinal Surgery, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China. chenzhixin@medmail.com.cn.
authors.forename: Zhixin
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D005770:Gastrointestinal Neoplasms / Q000188:drug therapy* / Q000556:secondary; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D000068877:Imatinib Mesylate / Q000627:therapeutic use*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy* / Q000473:pathology; D009367:Neoplasm Staging; D011300:Preoperative Care; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D000970:Antineoplastic Agents; D000068877:Imatinib Mesylate
keywords: Gastrointestinal stromal tumors; Overall survival; Preoperative imatinib mesylate; Progression-free survival