Determination of incidence and partial characterization of tumor‐associated antigens found in the urine of patients bearing solid tumors

Urine samples from patients with solid tumors and from donors without malignant disease were concentrated and tested for the presence of tumor-associated antigens. In the complement-fixation assay using serum from a source autologous with the source of the urine, 87.4% of cancer patients were positive, while only 6.9% of control donors were positive. When serum from an allogenic source was used, 94.7% of cancer patients and 35.1% of control donors were positive. Absorption of a cancer patient's serum with autologous tumor cells removed antibody activity to autologous and allogeneic urine samples. Normal lymphocytes, skin, or muscle-cell suspensions were ineffective as absorbents. The excretion of antigen into urine is dependent upon the presence of tumor. Surgical removal of tumor resulted in cessation of antigen excretion. The urine remained antigen-negative as long as the patient remained disease-free. The antigenic activity was heat-stable and comprised molecules of greater than 1,000,000 daltons which could be dissociated into smaller molecular weight active fractions by treatment with 6 M urea.