title: Prognostic Relevance of p53 Overexpression in Gastrointestinal Stromal Tumors of the Small Intestine: Potential Implication for Adjuvant Treatment with Imatinib.
abstract: OBJECTIVE
  Although genetic p53 aberrations are correlated with the prognosis of various types of cancer, their prognostic relevance is currently unclear in patients with gastrointestinal stromal tumors (GISTs) of the small intestine.
  
  
  METHODS
  Between 1994 and 2008, 113 patients with resected localized GISTs of the small intestine were included in this analysis. Patients who received pre- and/or postoperative chemotherapy were excluded. p53 overexpression was assessed by immunohistochemical staining and defined as expression in >10 % of tumor cells.
  
  
  RESULTS
  p53 overexpression was identified in 38 patients (34 %) and was significantly associated with epithelioid histology (p = 0.040) and high cellularity (p = 0.004). Relapse-free survival (RFS) significantly differed according to p53 overexpression (5-year RFS rates, 57 vs. 78 %; p = 0.005). By multivariate analysis, which included tumor necrosis, tumor size, mitotic count, and primary genotype, p53 overexpression significantly affected RFS with a hazard ratio of 3.50 (95 % confidence interval 1.48-8.25; p = 0.004).
  
  
  CONCLUSIONS
  p53 overexpression is an independent prognostic factor in patients with small intestinal GISTs. This suggests that p53 expression can be used to further stratify recurrence risk in patients with resected GISTs of the small intestine.
authors: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Changhoon
authors: C
authors: Yoo
authors: Department of Pathology, Ajou University School of Medicine, Suwon, Korea.
authors: Young Wha
authors: YW
authors: Koh
authors: Department of Pathology Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea. youngspark@amc.seoul.kr.
authors: Young Soo
authors: YS
authors: Park
authors: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Min-Hee
authors: MH
authors: Ryu
authors: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Baek-Yeol
authors: BY
authors: Ryoo
authors: Department of Pathology Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Hye Jin
authors: HJ
authors: Park
authors: Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Jeong Hwan
authors: JH
authors: Yook
authors: Department of Surgery, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Byung Sik
authors: BS
authors: Kim
authors: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors: Yoon-Koo
authors: YK
authors: Kang
mesh_terms: D000276:Adjuvants, Immunologic; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000378:metabolism; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D005770:Gastrointestinal Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D046152:Gastrointestinal Stromal Tumors / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D000068877:Imatinib Mesylate / Q000627:therapeutic use; D007124:Immunoenzyme Techniques; D007414:Intestinal Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D009367:Neoplasm Staging; D011379:Prognosis; D015996:Survival Rate; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D055815:Young Adult
chemical_list: D000276:Adjuvants, Immunologic; D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D000068877:Imatinib Mesylate