title: Retrospective analysis of extra-gastrointestinal stromal tumors.
abstract: OBJECTIVE
  To investigate the clinicopathologic features of patients with extra-gastrointestinal stromal tumors (EGISTs) in South Korea.
  
  
  METHODS
  A total of 51 patients with an EGIST were identified. The clinicopathologic features, including sex, age, location, tumor size, histology, mitotic rate, immunohistochemical features, genetic status and survival data, were analyzed.
  
  
  RESULTS
  The median age was 55 years (range: 29-80 years), and male:female ratio was 1:1.04. The most common site was in the mesentery (n = 15) followed by the retroperitoneum (n = 13) and omentum (n = 8). The median tumor size was 9.0 cm (range: 2.6-30.0 cm) and the median mitotic rate was 5.0/50HPF. (1/50 - 185/50). KIT was analyzed in 16, which revealed 10 cases with wild-type KIT and 6 cases with an exon 11 mutation. Among 51 patients, 31 patients had undergone surgery, and 10 had unresectable disease and had taken palliative imatinib, which resulted in 22.7 mo of progression-free survival. Of the patients who had undergone surgery, 18 did not take adjuvant imatinib, and 8 of these were categorized as "high risk" according to the risk criteria. However, the relapse-free survival was not different (P = 0.157) between two groups.
  
  
  CONCLUSIONS
  Because the biologic behaviors of GISTs differ according to the location of the tumor, a more stratified strategy is required for managing EGISTs including incorporation of molecular features.
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Jun Ho
authors: JH
authors: Yi
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Byeong-Bae
authors: BB
authors: Park
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Jung Hun
authors: JH
authors: Kang
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: In Gyu
authors: IG
authors: Hwang
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Dong Bok
authors: DB
authors: Shin
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Sun Jin
authors: SJ
authors: Sym
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Hee Kyung
authors: HK
authors: Ahn
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Soon Il
authors: SI
authors: Lee
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Do Hyoung
authors: DH
authors: Lim
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Keon Woo
authors: KW
authors: Park
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Young-Woong
authors: YW
authors: Won
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Sung Hee
authors: SH
authors: Lim
authors: Jun Ho Yi, Byeong-Bae Park, Division of Hematology-Oncology, Department of Internal Medicine, Hanyang University Seoul Hospital, Seoul 133-792, South Korea.
authors: Se Hoon
authors: SH
authors: Park
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D004252:DNA Mutational Analysis; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000737:chemistry / Q000235:genetics / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D009154:Mutation; D009364:Neoplasm Recurrence, Local; D011237:Predictive Value of Tests; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome; D047368:Tumor Burden
chemical_list: D014408:Biomarkers, Tumor; D019009:Proto-Oncogene Proteins c-kit
keywords: Gastrointestinal stromal tumor; Imatinib; Prognostic factor; Risk factor; Survival