Urinary amino acid excretion: comparison of normal individuals and patients with bladder cancer

The excretion levels of urinary amino acids obtained from acid hydrolysates were studied by gas chromatographic analysis in 29 normal individuals and 118 patients with bladder carcinoma. Leucine and isoleucine excretion were elevated in patients with bladder carcinoma as compared with normal subjects under the same experimental condition. Mathematical computer-assisted programs developed to aid in determining clusters of amino acid variables suggested that excretion of glycine, leucine, proline, and glutamic acid in men and concentrations of valine, serine, aspartic acid, phenylalanine, and lysine in women vary according to the invasiveness of the disease. These findings suggest that measurements of urinary amino acids may provide a useful parameter for the detection and aid in the staging of bladder carcinoma.