title: Plasma free amino acid profiling of five types of cancer patients and its application for early detection.
abstract: BACKGROUND
  Recently, rapid advances have been made in metabolomics-based, easy-to-use early cancer detection methods using blood samples. Among metabolites, profiling of plasma free amino acids (PFAAs) is a promising approach because PFAAs link all organ systems and have important roles in metabolism. Furthermore, PFAA profiles are known to be influenced by specific diseases, including cancers. Therefore, the purpose of the present study was to determine the characteristics of the PFAA profiles in cancer patients and the possibility of using this information for early detection.
  
  
  RESULTS
  Plasma samples were collected from approximately 200 patients from multiple institutes, each diagnosed with one of the following five types of cancer: lung, gastric, colorectal, breast, or prostate cancer. Patients were compared to gender- and age- matched controls also used in this study. The PFAA levels were measured using high-performance liquid chromatography (HPLC)-electrospray ionization (ESI)-mass spectrometry (MS). Univariate analysis revealed significant differences in the PFAA profiles between the controls and the patients with any of the five types of cancer listed above, even those with asymptomatic early-stage disease. Furthermore, multivariate analysis clearly discriminated the cancer patients from the controls in terms of the area under the receiver-operator characteristics curve (AUC of ROC >0.75 for each cancer), regardless of cancer stage. Because this study was designed as case-control study, further investigations, including model construction and validation using cohorts with larger sample sizes, are necessary to determine the usefulness of PFAA profiling.
  
  
  CONCLUSIONS
  These findings suggest that PFAA profiling has great potential for improving cancer screening and diagnosis and understanding disease pathogenesis. PFAA profiles can also be used to determine various disease diagnoses from a single blood sample, which involves a relatively simple plasma assay and imposes a lower physical burden on subjects when compared to existing screening methods.
authors.affiliation: Molecular Pathology and Genetics Division, Kanagawa Cancer Center, Yokohama, Japan. miyagi@gancen.asahi.yokohama.jp
authors.forename: Yohei
authors.initials: Y
authors.lastname: Miyagi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Higashiyama
authors.forename: Akira
authors.initials: A
authors.lastname: Gochi
authors.forename: Makoto
authors.initials: M
authors.lastname: Akaike
authors.forename: Takashi
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Miura
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Saruki
authors.forename: Etsuro
authors.initials: E
authors.lastname: Bando
authors.forename: Hideki
authors.initials: H
authors.lastname: Kimura
authors.forename: Fumio
authors.initials: F
authors.lastname: Imamura
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Moriyama
authors.forename: Ichiro
authors.initials: I
authors.lastname: Ikeda
authors.forename: Akihiko
authors.initials: A
authors.lastname: Chiba
authors.forename: Fumihiro
authors.initials: F
authors.lastname: Oshita
authors.forename: Akira
authors.initials: A
authors.lastname: Imaizumi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyano
authors.forename: Katsuhisa
authors.initials: K
authors.lastname: Horimoto
authors.forename: Osamu
authors.initials: O
authors.lastname: Tochikubo
authors.forename: Toru
authors.initials: T
authors.lastname: Mitsushima
authors.forename: Minoru
authors.initials: M
authors.lastname: Yamakado
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Okamoto
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood*
chemical_list: D005230:Fatty Acids, Nonesterified