Decrease in pyrrole-2-carboxylic acid excretion during lung cancer disease.

A statistically significant decrease of pyrrole-2-carboxylic acid in urine was observed in lung cancer of stage I (TNM classification) when compared to that of healthy miners (chronically exposed to radiation) from the uranium industry. The difference vanishes in stage II of the disease and reappears in stage III. While nonmalignant lung diseases (bronchopneumonia and chronic bronchitis) do not interfer in the stage I with the drop of pyrrole-2-carboxylic acid excretion, in stage III of lung cancer the decrease is less pronounced and cannot be differentiated from that found in bronchopneumonia or chronic bronchitis.