title: Prediction of lymph node metastasis and perineural invasion of biliary tract cancer by selected features from cDNA array data.
abstract: OBJECTIVE
  To better understand the nature of the malignancy of biliary tract carcinoma and evaluate the feasibility of its prediction by gene expression profiles.
  
  
  RESULTS
  We explored the gene expression profiles characteristic of progression and invasiveness in the cDNA array data obtained from 37 biliary tract carcinomas (15 bile duct, 11 gallbladder, 11 of ampulla of Vater). We pre-selected 51 and 100 genes for the presence versus absence of lymph node metastasis and perineural invasion on the basis of statistical difference. To search optimized sets of genes for prediction, we applied a sequential forward feature selection, minimizing leave-one-out error rates on a k-nearest neighbor classifier. We could predict lymph node metastasis and perineural invasion with an accuracy of 94 and 100%, respectively. When the 6-stage IA cancers without perineural invasion were precluded, a marked difference in gene expression (147 gene), discriminable with 100% accuracy, was noted between positive versus negative perineural invasion, suggesting that the acquisition of invasive character is rather a later molecular pathological event in biliary tract cancer.
  
  
  CONCLUSIONS
  The present method provides a powerful means of classifying biliary tract carcinomas. We also suggest that perineural invasion is an important target of array databased pattern classification, which may predict patient outcomes and facilitate the determination of the extent of surgery to minimize the risk of recurrence.
authors.affiliation: Department of Surgical Oncology, Division of Cancer Diagnostics and Therapeutics, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Murakawa
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Tada
authors.forename: Minoru
authors.initials: M
authors.lastname: Takada
authors.forename: Eiji
authors.initials: E
authors.lastname: Tamoto
authors.forename: Gaku
authors.initials: G
authors.lastname: Shindoh
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Teramoto
authors.forename: Akihiro
authors.initials: A
authors.lastname: Matsunaga
authors.forename: Kazuteru
authors.initials: K
authors.lastname: Komuro
authors.forename: Motoshi
authors.initials: M
authors.lastname: Kanai
authors.forename: Akiko
authors.initials: A
authors.lastname: Kawakami
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Fujiwara
authors.forename: Nozomi
authors.initials: N
authors.lastname: Kobayashi
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Shirata
authors.forename: Norihiro
authors.initials: N
authors.lastname: Nishimura
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Okushiba
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kondo
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Hamada
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Katoh
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshiki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Moriuchi
mesh_terms: D001659:Biliary Tract / Q000294:innervation; D001661:Biliary Tract Neoplasms / Q000235:genetics* / Q000473:pathology*; D002277:Carcinoma / Q000473:pathology* / Q000556:secondary*; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D009361:Neoplasm Invasiveness; D009420:Nervous System / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis; D011237:Predictive Value of Tests; D011379:Prognosis