Tumor-associated trypsin inhibitor (TATI) in the diagnosis of lung cancer.

To evaluate the usefulness of tumor-associated trypsin inhibitor (TATI) as a marker for the diagnosis of lung cancer we determined serum levels of this peptide in 255 patients with lung cancer and in 74 patients with chronic obstructive lung disease. A reference population consisting of 151 healthy volunteers was also studied. TATI concentrations were measured by radioimmunoassay. As a cut-off point we used the 99th percentile of the TATI concentrations in a reference population, which was 32 micrograms/l. TATI does not appear to be a good tumor marker in lung cancer. Its sensitivity is poor in comparison with CEA and TPA. The correlation between TATI levels and stage of the disease and histological type was weak.