Measurements of hormonal peptides in the bronchoalveolar fluid as tumor markers of lung cancer

A large number of lung cancers contains and releases a variety of neuropeptides such as adrenocorticotropic hormone (ACTH) and beta-endorphin (beta-EP). Although the plasma levels of these peptides have been extensively investigated as possible markers that may help in the early diagnosis of the disease, the data collected have shown their limited clinical usefulness. The present study was undertaken to evaluate whether corticotropin-releasing hormone (CRH), ACTH or beta-EP levels in the bronchoalveolar lavage (BAL) fluid of patients with lung cancer might have been more helpful. To accomplish this, bronchial lavages were carried out in 25 patients affected by lung cancer (17 squamous carcinomas, 4 adenocarcinomas, 2 small cell carcinomas, and 2 not classified) and 18 controls. After centrifugation, BAL fluid was extracted using cartridges of SepPak C-18 and CRH, ACTH and beta-EP levels were measured by radioimmunoassay. CRH and ACTH BAL levels in patients with lung cancer were not significantly different from those of controls. beta-EP concentrations in the BAL fluid were about 200-fold higher than those of ACTH and showed a downward trend (p = 0.08, Mann-Whitney test) in patients with cancer. No histologic tumor type was associated with particularly elevated levels of any of the peptides measured, not even the two patients with small cell carcinoma, a tumor type which tends to release higher peptide levels. Therefore we conclude that measurements of CRH, ACTH and/or beta-EP in the BAL fluid are not useful diagnostic tumor markers of lung cancer