RESUMEN
BACKGROUND: It has been proven that cytokeratins (CKs) are useful tumor markers for the follow-up, treatment monitoring and prognosis evaluation of lung cancer and among these, tissue polypeptide antigen (TPA) plays an important role. Nevertheless, only a small number of studies have been reported about their diagnostic capacity. Bronchoalveolar lavage (BAL) can be divided into two fractions: bronchiolar (BF) and alveolar (AF). For the above reasons, our aims were (1) to analyze the diagnostic usefulness of TPA in the BAL of lung cancer patients and (2) to observe if, in lung cancer patients, TPA levels in the two BAL fractions are different. This should mean that the study of tumor markers in the BAL should be carried out in both fractions to increase their diagnostic capacity. METHODS: We studied 289 BALs divided into two phases. In phase I, TPA was analyzed in the BAL of six groups of subjects (healthy persons, chronic bronchitis, asthma, respiratory infections, diffuse interstitial pulmonary diseases and lung cancer). In phase II, TPA was studied in both BAL fractions of a group of patients with lung cancer. RESULTS: We observed that TPA levels were significantly higher in the BAL of patients with bronchogenic neoplasias. In these patients, TPA was increased in the BF of the lavage in relation to the AF. In smoker patients with pulmonary carcinomas, TPA was higher in the AF of the BAL than in the lavage of non-smokers. This did not occur in the BF. We found no relation between the TPA concentrations and cancer histology. CONCLUSIONS: We believe that TPA is a useful tumor marker with diagnostic capacity and this capacity is increased when it is studied in the two BAL fractions. Smoking habit may play a role in the secretion of tumor markers by the tumor cells.