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.