Bronchoalveolar lavage in lung cancer - diagnostic value and assessment of the anti-cancer immune response

Lung cancer is the most serious neoplasm worldwide. Despite significant progress in the treatment regimens and ongoing research development, lung cancer remains the first cause of cancer death in both sexes, and 5-year survival does not exceed 15%. The failure of host defense against this solid tumor is well known. The mechanisms of escaping from immune surveillance include, among others, changing of cancer cells' antigenicity, impaired function of antigen-presenting cells, enhancing apoptosis of tumor-infiltrating cytotoxic cells, and immune response inhibition by regulatory cells. To recognize these mechanisms well is very important in anti-cancer therapy. The small number of resectable cases of lung cancer causes very low availability of tumor environment examination. The cellular pattern and cytokine concentration in bronchoalveolar fluid (BALF), which can be performed during diagnostic bronchofiberoscopy, reflects the changes in tumor milieu. The character of BAL fluid qualifies this material for analysis by flow cytometry with precise evaluation of lymphoid cell phenotype and measurement of the surface and cytoplasmic molecules' regulatory properties. The results of previous studies have shown that the BAL fluid composition well characterized the local immune response in patients with lung cancer. However, many of the cases resulted from the influence of tobacco smoke, which is inextricably connected with cancer. Furthermore, BAL fulfills the diagnostic criteria in peripheral tumors and in disseminated malignant changes in the lung. We discuss the usefulness of this well-standardized method in the diagnosis of lung cancer and in the assessment of the local immune response prior to systemic treatment.