title: Elemental fingerprinting of tumorous and adjacent  non-tumorous tissues from patients with colorectal cancer  using ICP-MS, ICP-OES and chemometric analysis.
abstract: Tumorous and adjacent non-tumorous paired biopsies from 38 patients with colorectal cancer were analyzed by inductively coupled plasma mass spectrometry and inductively coupled plasma optical emission spectrometry after low-volume microwave digestion. 18 elements were investigated: Ag, Al, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Ni, P, Pb, S, Se and Zn. Different chemometric tools were used for data evaluation: Wilcoxon signed rank test, Hieratical clustering analysis, principal component analysis (PCA) and linear discriminant analysis (LDA). With the exception of Al, tumours were observed to have significantly more elevated concentrations of essential elements as compared to non-tumours. On the contrary, elements considered potentially carcinogenic such as Cr, Ni, Mo or Co do not display significant differences. When PCA was applied, different components were obtained for tumorous and non-tumorous tissues. When LDA was applied for the elements studied (including essential and non-essential elements) about 90% of cases were correctly classified.
authors.affiliation: Departamento de Química Analítica y Alimentaria, Área de Química Analítica, Facultad de Química, Universidad de Vigo, As Lagoas-Marcosende s/n, 36310 Vigo, Spain.
authors.forename: Isela
authors.initials: I
authors.lastname: Lavilla
authors.forename: Marta
authors.initials: M
authors.lastname: Costas
authors.forename: Pilar San
authors.initials: PS
authors.lastname: Miguel
authors.forename: Jorge
authors.initials: J
authors.lastname: Millos
authors.forename: Carlos
authors.initials: C
authors.lastname: Bendicho