In preliminary studies, the polyamines (primarily putrescine, spermidine and spermine), recognized as regulators of growth and differentiation of cells, were present in greater amounts in urine and serum of patients with cancer than appropriate controls. Evidence now suggests that analysis of serum polyamines may serve as a sensitive indicator of solid tumors. We wish to perform serum polyamine assays on patients with carcinoma of the colon and rectum (including Gardner's syndrome), one of the most common solid tumors, and compare such values with serum carcinoembryonic antigen (CEA) determinations from identical sera to correlate the results with the clinical status of patients. Serum polyamines will be measured using an amino acid analyzer while CEA will be determined by radioimmunoassay. The effects of 5-FU and irradiation on established cell lines of colon carcinoma will be examined, and intra- and extra-cellular polyamines and CEA content measured. These results will be utilized to interpret more precisely the metabolism and excretion of polyamines found in human sera.