Urinary
nucleosides are associated with many types of
cancer. In this study, six targeted urinary
nucleosides, namely
adenosine,
cytidine,
3-methylcytidine,
1-methyladenosine,
inosine, and 2-deoxyguanosine, were chosen to evaluate their role as
biomarkers of four different types of
cancer: lung cancer, gastric cancer, colon cancer, and
breast cancer. Urine samples were purified using solid-phase extraction (SPE) and then analyzed using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The Mann-Whitney U test and Principal Component Analysis (PCA) were used to compare differences in urinary
nucleosides between patients with one of four types of
cancer and healthy controls. The diagnostic sensitivity of single
nucleosides for different types of
cancer ranged from 14% to 69%. In contrast, the diagnostic sensitivity of a set of six
nucleosides ranged from 37% to 69%. The false-positive identification rate associated with the set of six
nucleosides in urine was less than 2% compared with that of less than 5% for a single
nucleoside. Furthermore, combining the set of six urinary
nucleosides with
carcinoembryonic antigen improved the diagnostic sensitivity for
colon cancer. In summary, the study show that a set of six targeted
nucleosides is a good diagnostic marker for breast and
colon cancers but not for lung and
gastric cancers.