Fluorescence characteristics of human urine from normal individuals and ovarian cancer patients.

Early diagnostics of ovarian cancer is difficult, because there are no symptoms until the disease has progressed to an advanced stage. As urine contains many intrinsic fluorophores, modern fluorescence techniques are perspective candidates for new routine urine tests. The presented work deals with differences in the fluorescence of metabolites in urine of ovarian cancer patients comparing to healthy volunteers using the fluorescence excitation-emission matrices. The most serious differences were found in undiluted urine at the fluorescence emission wavelengths from 400 nm to 460 nm when excited at 310 - 390 nm. Statistical analyses of our data have shown a 5-fold reduction in the intensity of the peak at 330/420 nm (excitation/emission wavelength) for undiluted urine samples excreted by cancer patients as compared to those of normal donors. Moreover, the ratio of intensities of the peaks at 370/440 nm and at 330/420 nm is 18-times elevated in urine excreted by patients with ovarian cancer as compared to healthy urine samples. The observed changes could be interpreted as reduction of the presence of pyridoxic acid, whereas blue-fluorescing pteridines becomes dominant in excitation-emission matrices of cancer urine samples in comparison to healthy donors. We suggest pteridines, which are related to cellular metabolism, as suitable candidates for neoplasia-associated fluorescent markers in human urine. Our work showed that monitoring of human urine fluorescent metabolites offers an alternative for ovarian cancer screening.