title: Colorectal gastrointestinal stromal tumors (GISTs): a retrospective study of reported cases.
abstract: OBJECTIVE
  Although with malignant potential, there are limited information about colorectal GISTs due to their relatively low incidence among large intestine diseases and the lack of sufficient associated case reports. The aim of the study is to obtain a better understanding of colorectal GISTs and to investigate the optimal treatment for it.
  
  
  METHODS
  Clinical data of 90 patients with colorectal GISTs published in the literature from 2003 to 2009 were analyzed with emphasis on pathology, treatment and prognosis.
  
  
  RESULTS
  The patients with tumor necrosis had a high relapse rate (p = 0.003) and a bad prognosis (p < 0.001) after surgery with negative margins (R0). Tumor necrosis had a significantly positive correlation with risk grades (p < 0.001). On the other hand, the mixed cell type had a significantly positive correlation with tumor necrosis (p = 0.016). Of the 67 cases with R0 resection, the difference of disease-free survival between the low-risk and high-risk was statistically significant (p = 0.003). Although, this was not statistically significant between the low risk and intermediate risk (p = 0.160) as well as intermediate-risk and high-risk (p = 0.229). But the high-risk had a marked relapse rate (54.8%), in comparison with the intermediate-risk (7.1%).
  
  
  CONCLUSIONS
  High-risk colorectal GISTs showed a poor outcome. A complete resection followed by routine use of tyrosine kinase inhibitors is recommended. Surgery with negative margins is the main treatment for non-high-risk group. The GISTs with tumor necrosis or mixed cell type implicate a malignant potential and a poor outcome. More attention should be paid and an extensive follow-up is warranted in this population.
authors.affiliation: Department of Colorectal Surgery, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, P R China.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Cheng
authors.forename: Dong
authors.initials: D
authors.lastname: Chen
authors.forename: Yangjing
authors.initials: Y
authors.lastname: Wang
authors.forename: Jinhai
authors.initials: J
authors.lastname: Wang
authors.forename: Jianjiang
authors.initials: J
authors.lastname: Lin
authors.forename: Wenbin
authors.initials: W
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies