Fibronectin in bronchoalveolar lavage fluid in lung cancer:: Tumor or inflammatory marker?

Objective: To evaluate the potential value of the level of fibronectin (FN) in the bronchoalveolar lavage fluid (BALF) as a lung tumor marker. Method: We compare the results of determinations in the tumor-bearing and tumor-free lungs of 38 patients with lung cancer, in 19 patients with benign lung diseases and in 13 healthy control subjects. FN was determined in BALF by a competitive ELISA and was also measured in plasma with a nephelometric assay. FN levels in BALF are expressed also referred to total protein content (ng FN/mg TP). Results: The distribution of FN levels in BALF was not gaussian, and the levels in cancer patients were significantly greater than in healthy controls or in the contralateral lung. There was no significative difference in the levels in cancer compared with several benign conditions. In this study we observed a positive correlation between FN levels and total protein and polymorphonuclear leukocytes in BALF in the lung cancer and benign diseases group: Conclusion: These results do not support the possibility that FN levels in BALF were a general marker of lung cancer, and suggest that FN may mark the existence of pathologic lung processes associated with inflammation and, perhaps, tissue repair after bronchopulmonary injury.