title: DPC4 expression in the small intestinal adenocarcinomas.
abstract: BACKGROUND
  Small intestinal adenocarcinomas (SACs) are rare malignancies of the alimentary tract with uncertain carcinogenesis.
  
  
  METHODS
  We investigated the expression of deleted in pancreatic cancer 4 (DPC4) in 188 cases of surgically resected SACs, using tissue microarray technology.
  
  
  RESULTS
  Twenty-four of the 188 tumors showed complete loss of Smad4/DPC4 expression in cytoplasm (score, 0; 12.8%). Eighty-four and 31 cases were moderately and strongly positive, respectively (score, 2 and 3; 44.7% and 16.5%, respectively) and 49 cases were focally or weakly stained (score, 1; 29.1%). Immunohistochemistry analysis showed that the expression of Smad4/DPC4 was related to an increased risk of lymphatic invasion but not to other clinicopathological features of the tumors (tumor location, differentiation, growth pattern, T stage, direct invasion, vascular invasion, and nodal metastasis). There was no significant association between Smad4/DPC4 expression and patient survival.
  
  
  CONCLUSIONS
  The present research is the first study to evaluate Smad4/DPC4 expression in a large sample of SACs with clinicopathologic correlation. Future studies should focus on the immunohistochemical and molecular characteristics of SACs to clarify their tumorigenesis.
authors.affiliation: Department of Pathology, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: Sun Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Eunsil
authors.initials: E
authors.lastname: Yu
authors.forename: Young Kyung
authors.initials: YK
authors.lastname: Bae
authors.forename: Kee-Taek
authors.initials: KT
authors.lastname: Jang
authors.forename: Joon Mee
authors.initials: JM
authors.lastname: Kim
authors.forename: Han-Ik
authors.initials: HI
authors.lastname: Bae
authors.forename: Seung-Mo
authors.initials: SM
authors.lastname: Hong
authors.forename: Ghil Suk
authors.initials: GS
authors.lastname: Yoon
keywords: Adenocarcinoma; Immunohistochemistry; Intestine, small; Smad4/DPC4