[Free serum amino acids in patients with tumors of different sites--tumor-induced imbalances].

We analysed 10 free serum amino acids of altogether 8 different malignant organ localisations before therapy and compared this with reference levels. We investigated asparaginic acid, glutaminic acid, glycine, alanine, valine, methionine, leucine, isoleucine, tyrosine and phenylalanine. All investigated amino acids with the exception of methionine show an elevated level compared to normal one. After successful therapy the elevated levels returned to normal ones and could be found increased in recurrent diseases. The analysis of amino acids in serum is a good method in therapeutic monitoring.