A significant part of our investigation is concerned with the structure elucidation of fifteen new substances that we have isolated from cancer urine. Eleven of the fifteen unknowns (E, F, G, H, J, K, L, M, N, O and P) are from the urines of colon carcinoma patients, three (unknowns D, I and Y) are from the urine of chronic myelogenous leukemia, and one (unknown X) is isolated from the breast carcinoma urine. In addition to these fifteen, three (unknowns alpha, beta and gamma) are isolated from the normal urines. Preliminary information through uv, nmr and chromatography methods indicates that these compounds can be classified into the purines, pyrimidines, imidazoles and nucleosides. We suggest that these substances are derived most probably from the anabolic and catabolic pathways of tumor nucleic acids in man. Another part of our investigation deals with the study on the source of origin and on biochemical and clinical significance of the four new substances that have recently been identified in the Principal Investigator's laboratory. The new urinary compounds are: N6-succinyladenosine (1); N'-beta-D-ribofuranosylpyridin-4-one-3-carboxamide (2); 2'-O-methyl-uridine (3); and 6-amino-3-methyl-5-(N-formylmethylamino)uracil (4). The source of origin of the compounds 2 and 4 will be determined by administration of selected radioactive precursors to normal and tumor bearing rats, followed by urinary analysis. The new anabolic modified nucleosides (1 and 2, Chart II) will be estimated by radioimmunoassay and by the GC-MS method in the urines of the patients with colon carcinoma, chronic myelogenous leukemia, Hodgkin and non-Hodgkin lymphoma and in normal subjects. On the whole this study will provide structures of several new urinary purines, pyrimidines, nucleosides and related compounds. Some of them in conjunction with other substances may well serve as quantitative tumor markers or indicators of tumor activity in assessing the treatment of certain cancers.