title: L-amino acid transporter 1 may be a prognostic marker for local progression of prostatic cancer under expectant management.
abstract: BACKGROUND
  Oncocytic L-amino acid transporter (LAT) 1 could be a target of new molecular therapy against malignancies.
  
  
  OBJECTIVE
  To assess the correlation between overexpression of LAT1 and local progression (LP) in prostatic carcinoma (PC) patients under expectant management (EM).
  
  
  METHODS
  This retrospective study analyzed 109 patients with PC who received EM from 1991 to 2006. The expression of LAT1, LAT2, and CD98, as well as Ki-67 labeling indices (LI), was analyzed immunohistochemically in first biopsy or TUR samples diagnosed as adenocarcinomas.
  
  
  RESULTS
  Of the 109 patients, 44 (40%) showed LP on clinical examinations, whereas 65 showed stable disease (SD). LAT1 score and intensity were significantly higher in the LP than in the SD group, as well as among Gleason score (GS)-low (GS < 7) patients who were associated with low-risk. When the LP group was subdivided by D'Amico risk category (low-, intermediate- and high-risk groups), each showed higher LAT1 expression than the SD group. LAT1 expression did not correlate with GS or Ki-67 LI.
  
  
  CONCLUSIONS
  Independently of GS, aberrant overexpression of LAT1 in prostatic adenocarcinoma could predict LP under EM. Although prostate biopsy samples are small, LAT1 may be a novel prognostic biomarker of LP.
authors.affiliation: Department of Pathology, Kitasato University School of Medicine, Kanagawa, Japan.|Department of Pathology of Biological Responses, Kitasato University Graduate School of Medical Science, Kanagawa, Japan.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Yanagisawa
authors.affiliation: Department of Urology, Kitasato University School of Medicine, Kanagawa, Japan.
authors.forename: Takefumi
authors.initials: T
authors.lastname: Satoh
authors.affiliation: J-Pharma Co., Ltd., Kanagawa, Japan.
authors.forename: Kiyomi
authors.initials: K
authors.lastname: Hana
authors.affiliation: Department of Pathology, Kitasato University School of Medicine, Kanagawa, Japan.|Department of Pathology of Biological Responses, Kitasato University Graduate School of Medical Science, Kanagawa, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Ichinoe
authors.affiliation: Department of Pathology, Kitasato University School of Medicine, Kanagawa, Japan.|Department of Pathology of Biological Responses, Kitasato University Graduate School of Medical Science, Kanagawa, Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Nakada
authors.affiliation: J-Pharma Co., Ltd., Kanagawa, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Endou
authors.affiliation: Department of Pathology, Kitasato University School of Medicine, Kanagawa, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Okayasu
authors.affiliation: Department of Pathology, Kitasato University School of Medicine, Kanagawa, Japan.|Department of Pathology of Biological Responses, Kitasato University Graduate School of Medical Science, Kanagawa, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Murakumo
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D000368:Aged; D000369:Aged, 80 and over; D027182:Amino Acid Transport System y+ / Q000096:biosynthesis / Q000235:genetics; D014408:Biomarkers, Tumor / Q000096:biosynthesis* / Q000235:genetics; D018450:Disease Progression; D027301:Fusion Regulatory Protein 1, Light Chains / Q000096:biosynthesis / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D019394:Ki-67 Antigen / Q000096:biosynthesis; D027283:Large Neutral Amino Acid-Transporter 1 / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology / Q000601:surgery; D020728:Transurethral Resection of Prostate
chemical_list: D027182:Amino Acid Transport System y+; D014408:Biomarkers, Tumor; D027301:Fusion Regulatory Protein 1, Light Chains; D019394:Ki-67 Antigen; D027283:Large Neutral Amino Acid-Transporter 1; C420646:SLC7A8 protein, human
keywords: L-type amino acid transporter 1; Prostatic carcinoma; expectant management; immunohistochemistry; prognosis