An analytical approach based on excitation-emission fluorescence spectroscopy and chemometrics for the screening of prostate cancer through urine analysis: A proof–of–concept study

In the present feasibility study, excitation-emission fluorescence spectroscopy has been investigated, as a rapid
and accurate analytical method for the development of a tentative model for the early screening of prostate
cancer directly through urine analysis in order to provide reliable results while improving patient compliance.
Sixty-nine urine samples (46 samples from patients with histologically proven prostate cancer and 23 from
healthy donors) were provided, by the University of Pisa, Urology Unit. The excitation-emission fluorescence
measurements were performed on centrifugated urine samples at room temperature on a Perkin-Elmer LS55B
luminescence spectrometer and the corresponding data array was analysed with parallel factor analysis
(PARAFAC).
From a synergistic analysis of the obtained results, four main fluorophores, corresponding to four selected
PARAFAC factors, were recognizable in the urine excitation-emission matrices (EEMs) and the respective species
could be potential markers in the differentiation among healthy and cancer samples. PARAFAC results, in terms
of extracted scores, coupled with discriminant algorithms, allowed to develop a first attempt of healthy/cancer
discrimination model. The chemometrics models show promising correlation between some of the depicted
fluorophores and the disease state. However, considering the limited cohort (not only in terms of number but also
of representativeness), this study must be considered as a proof of concept; a more sound and statistically
relevant sampling must be performed in order to consider the confounding factors in the cohort treated and to
develop an analytical approach applicable in real scenarios.