Affiliations: [a] Department of Pathology, Kitasato University School of Medicine, Kanagawa, Japan | [b] Department of Pathology of Biological Responses, Kitasato University Graduate School of Medical Science, Kanagawa, Japan | [c] Department of Urology, Kitasato University School of Medicine, Kanagawa, Japan | [d] J-Pharma Co., Ltd., Kanagawa, Japan
Correspondence:
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Corresponding author: Nobuyuki Yanagisawa, Department of Pathology, Kitasato University School of Medicine, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0374, Japan. Tel.: +81 42 778 9020; Fax: +81 42 778 9124; E-mail: [email protected]
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.
